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Skeletal Series 11: The Human Foot

4 Sep

The human foot is as distinctive and as complex as the human hand (D’Août et al.  2010).  The foot, or Pes, forms the distal terminus of the leg.  It helps to perform the two basic important functions of shock absorption and propulsion during bipedal locomotion, both of which require a high degree of stability.  The foot bones are the serial homologs of the hand bones an each foot individually is comprised of 26  individual skeletal elements as opposed to the hand’s 27  individual skeletal elements, indicative of the differing evolutionary roles of both limbs with the digits undergoing reduction and modification in mammals (White & Folkens 2005: 225).

As White & Folkens (2005: 292) note, the ‘human foot has changed dramatically during its evolution from a grasping organ to a structure adapted to bipedal locomotion’, where ‘mobility, flexibility and grasping ability has been lost’.  As humans are bipedal walkers the feet must take the full weight of the body during locomotion and this is reflected in hard and soft tissue anatomy (D’Août et al. 2008, D’Août et al. 2010, Gosling et al. 2008, Jarmey 2003).  The diagram below demonstrates the robust and compact nature of the pes elements.

Foooooot

The human foot, highlighting the articulated individual skeletal elements in dorsal and lateral view. Note the arch of the foot, the size of the calcaneus and general robusticity of the bones in comparison to the hand bones (Image credit: WebMD 2013).

Excavation

The excavation of the human skeleton should, where possible, be conducted with patience and great care for the recovery of all skeletal material possible (Brothwell 1981).  The elements that make up the foot, a total of 26 individual bones altogether (see below), are sturdy and largely compact bones, although it is likely that there will not be complete recovery of the distal phalanges due to their smaller size.  In supine and crouched burials the foot bones are likely to survive, although care must be taken when excavating at an unknown burial depth (Larsen 1997).  In cremation remains of individuals from archaeological sites it is still possible for certain elements to be recognised and described, especially in the case of the compact tarsal bones (Mays 1999).  In crowded burial grounds where the body is laid out in a supine position (lying flat on the back), as n the photograph below, burials often intersect each other, cutting off the lower part of the legs (Mays 1999).  This is a common feature in crowded burial grounds, and care must be taken when excavating and assigning individual skeletal elements to specific individual skeleton’s (Brothwell 1981).

bones brodsworth 07pic3 - Copy

A photograph of a Medieval burial ground near Brodsworth, Yorkshire, UK, from the 2007 excavation. Note the orientation and sequential laying of supine burials, and how the lower portion of the legs have been covered or destroyed by other burials. Courtesy of the University of Hull and the Brodsworth project.

Basic Musculature and Skeletal Anatomy

There are 26 bones in the human foot which are grouped into 7 tarsals, 5 metatarsals and 14 phalanges, for a total of 33 joints, of which 20 are actively articulated (See image below for skeletal elements in articulation, and Gosling et al. 2008, Mays 1999, White & Folkens 2005, for further reference).  The main joints of the foot itself include the transverse tarsal joint and tarsometatarsal joint (see figure below).  The talocrural (ankle) joint, the articulation between the leg and the foot, forms an important part of the stability of the foot, one of the main differences behind the pes and the manus (the wrist is extremely movable and flexible in comparison to the ankle).  Unlike the hand the foot cannot grasp and is not capable of fine motor movement, however the adipose tissue and plantar fascia (or aponeurosis) is tightly packed underneath the heel (calcaneus bone) for shock absorption during locomotion (Gosling et al. 2008: 304).  The stability of the ankle joint is strengthened by the wedge shaped articulation of the talus and calcaneus bones and by the strong collateral ligaments helping to tightly pack the anatomy during movement (Gosling et al. 2008: 304-305).

footbones

The individual sections and bones of a right sided human foot, which includes the tarsals, metatarsals, and phalanges from proximal to distal (Image credit: Encyclopedia Britannia 2007).

It is important to note here the two main arches of the human foot, the transverse arches and the medial and lateral longitudinal arches.  The functional anatomy of the arches allows the foot to remain stable during the pressures and energy exertion of locomotion but also retain flexibility so that it can grip different surfaces whilst enhancing forward propulsion (Gosing et al. 2008: 309).  The transverse arch is located along the cuneiforms, the cuboid bone and all of the metatarsal bases, and simply forms a domed shaped which strengthens the foot during locomotion.  The medial longitudinal arch is the highest of the arches and runs along the instep of the foot, alongside the calcaneus, talus, navicular, and cuneiform bones and up to the first three metatarsals (Gosling et al. 2008: 309).  The lateral longitudinal arch is lower and flatter than the media arch and runs alongside the calcaneus, the cuboid, and the fourth and fifth metatarsals (Gosling et al. 2008: 2010).

The arches are supported in their skeletal frame by a complex arrangement of extrinsic and intrinsic muscles, ligaments and tendons.  The sole of the foot contains numerous intrinsic muscles which mimic the muscles found in the hand, which include digitorum (flexor/abductor) and lumbrical muscles, whilst the plantar view houses the inter-osseus planar muscles (Gosling et al. 2008: 284).  It is worth remembering that the majority of the larger muscles that articulate and move the foot are located in the leg itself (soleus, gastrocnemius, and the anterior/posterior tibial muscles).  Although I will not discuss the soft tissues further, I highly recommend the ‘Human Anatomy Colour Atlas and Textbook’ by Gosling et al. (2008) as a key reference source.  The book has a high number of quality dissection photographs and anatomical diagrams clearly highlighting the different muscle, ligament and tendon structures.

Skeletal Elements: Tarsals

The 7 tarsal bones of the foot help to form the longitudinal and transverse arches of the foot, which is often called the tarsus.  The talus articulates superiorly with the distal tibia and fibula, the calcaneus forms the heel of the foot and supports the talus (White & Folkens 2005: 291).  The navicular sites between the 3 cuneiforms and the head of the talus (White & Folkens 2005: 292).  The 3 cuneiforms and the cuboid act as a second row of tarsal bones and articulate with the proximal heads of the 5 metatarsals.

tarsals_labeled

Dorsal view of the tarsal elements and proximal metatarsals (Image credit: University of Cincinnati).

The Talus

The talus (astragalus in animals) is the 2nd largest tarsal and sits atop of the calcaneus, between the tibia and the fibula.  It is distinct in it’s saddle shape, with a head (that sides medially when viewed from above) and a body that forms the posterior portion of the bone.

The Calcaneus

The largest tarsal, forming the heel bone, the calcaneus is located inferior of the talus and supports the distal portion of the foot.  An intact calcaneus is extremely distinct, and can be sided by placing the ‘heel’ away from you and the articular surfaces superiorly, and the shelf (sustentaculum tali) should point the side it is from.

The Cuboid

The cuboid is located on the lateral side of the foot, between the calcaneus and the 4th and 5th metatarsals.  It is distinct in appearance because of its large size with a cuboidal body.  There is no articular surface on the lateral side of the bone, and the inferior surface has a pronounced cuboid tuberosity.

The Naviculuar

The navicular sits snugly between the talus and the cuneiform elements, and has a distinct concave proximal surface.  A tubercle points medially when viewed from the view of the talus.  It is similar in shape to the scaphoid carpal.

The Cuneiforms:

Medial

The medial cuneiform is the largest of the three cuneiforms, sitting between the navicular and base of the first metatarsal.  It is less of a wedge shape than the other two cuneiforms, and distinguished by it’s ‘kidney-shaped facet for the base of the first metatarsal’ (White & Folkens 2005: 298).

Intermediate

This cuneiform is the smallest of the cuneiforms and is located between navicular and the 2nd metatarsal base.  It articulates on either side with the lateral and medial cuneiforms.  The non-articular dorsal surface is key for siding, with a projecting surface points towards the side it comes from when the concave facet is pointed away from the holder (White & Folkens 2005: 298).

Lateral

Located at the centre of the foot, and intermediate in size between the intermediate and medial cuneiform, the lateral cuneiform sits at the base of the foot.  It articulates distally with the 2nd, 3rd and fourth metatarsal bases, proximally with the navicular, medially with the intermediate cuneiform and laterally the cuboid (White & Folkens 2005: 299).

Metatarsals

The 5 rays of the metatarsals are typically labelled as MT 1-5, with MT1 representing the hallux, or the big toe (as the thumb is named the pollex).  The metatarsals are all ‘tubular bones with rounded distal articular facets (heads) and more squarish proximal ends (bases)’ (White & Folkens 2005: 300).  They are more easily sided by the morphology of their bases.  It is important to note that each of the tarsals in the distal row (either of the 3 cuneiforms or the cuboid above) articulates with one or more of the metatarsal bases (White & Folkens 2005: 300).  The first metatarsal is the most massive and squat, whilst all non hallucial metatarsals articulate with each other.  The fifth metatarsal bears a distinctive blunt styloid process on it’s lateral side that makes it fairly identifiable.

metatarsal-phalangeal-joint

A basic dorsal view of the metatarsal and phalangeal bones in the right foot. Note that the hallux (first digit medially) has only a proximal and a distal phalanx whilst the other digits have a proximal, intermediate and distal phalanx (Source).

Phalanges

The foot phalanges are the same in design as the hand phalanges with heads, bases and shafts but are much shorter and squatter than the hand phalanges.  Again they come  in three rows, with 5 proximal phalanges4 intermediate phalanges and 5 distal phalanges;  it should be noted that the MT1 hallux has, as does the thumb (pollex), only the proximal and distal phalanges with no intermediate phalanx, and is remarkably more chunkier then either of the other four rays.

Each Proximal Phalanx displays a ‘single, concave proximal facet for the metatarsal head and a spool-shaped surface distally’ (White & Folkens 2005: 306).

Each Intermediate Phalanx displays a ‘double proximal articular facet for the head of the proximal phalanx’, and again have a trochlea shaped distal articular facet (White & Folkens 2005: 306).

Each Distal Phalanx displays a double articular proximal facet for the head of the intermediate phalanx and a terminal tip of the bone, resulting in a non-articular pad (White & Folkens 2005: 307).

These phalanges are all much shorter than their companions in the hand, with the foot phalanges having a more circular shaft cross section compared to the D shape  shaft of the hand phalanges.  Foot phalanges generally display a more constrictive shaft than hand phalanges, although it can be difficult to side them and it is best done with a full replica or whole specimens for comparative analysis (White & Folkens 2005: 308).  

Further Online Sources

  • A detailed map of each element and the surrounding musculature (as well as relaxing classical music!) can be found on the website of the UMFT Department of Anatomy and Embryology site.  Be aware there are detailed anatomical prosection and dissection diagrams, but it is a free, fascinating and wonderful source (and with the music especially relaxing!).
  • A number of websites have detailed diagrams and photographs of the foot from a medial/lateral and a dorsal/planar view, including this site and this one.
  • Finally, do you know your tarsal bones? Test yourself here!

Bibliography

Brothwell, D. R. 1981. Digging Up Bones: The Excavation, Treatment and Study of Human Skeletal Remains.  Ithica: Cornell University Press.

D’Août, K., Pataky T.C., De Clercq, D. & Aerts, P. 2009. The Effects of Habitual Footwear Use: Foot Shape and Function in Native Barefoot Walkers. Footwear Science1 (2): 81. doi:10.1080/19424280903386411 

D’Août, K., Meert, L., Van Gheluwe, B., De Clercq, D. & Aerts, P. 2010. Experimentally Generated Footprints in Sand: Analysis and Consequences for the Interpretation of Fossil and Forensic Footprints. American Journal of Physical Anthropology141: 515–525. doi: 10.1002/ajpa.21169

Gosling, J. A., Harris, P. F., Humpherson, J. R., Whitmore I., & Willan P. L. T. 2008. Human Anatomy Color Atlas and Text Book. Philadelphia: Mosby Elsevier.

Jarmey, C. 2003. The Concise Book of Muscles. Chichester: Lotus Publishing. 

Jurmain, R. Kilgore, L. & Trevathan, W.  2011. Essentials of Physical Anthropology International Edition. London: Wadworth.

Larsen, C. 1997. Bioarchaeology: Interpreting Behaviour From The Human Skeleton. Cambridge: Cambridge University Press.

Marsland, D. & Kapoor, S. 2008. Rheumatology and Orthopaedics. London: Mosby Elsevier.

Mays, S. 1999. The Archaeology of Human Bones. Glasgow: Bell & Bain Ltd.

White, T. & Folkens, P. 2005. The Human Bone Manual. London: Elsevier Academic Press.

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Documentary on Fibrodysplasia Ossificans Progressiva

24 Nov

There was recently a documentary on Channel 4 (in Britain) that highlighted an individual with Fibrodysplasia Ossificans Progressiva (FOP), a progressive bone disease in which the bodies natural repair mechanism causes fibrous tissues (including ligaments, tendons and muscles) to become ossified when damaged or hurt.  Typically lumbered with the name Stone Man Syndrome, the genetic disease itself is thankfully very rare with a rough prevalence of around 1 in every 2 million people.  A total of 700 cases have thus far been confirmed out of presumed 2500 cases worldwide at the current time.  The disease is ultimately devastating for the individual affected as it can lead to full ossification of every joint in the body, whilst the ossification of the fibrous tissues is typically a very painful process.  A full introduction to the disease can be found here on the emedicine website.

The program, entitled ‘The Human Mannequin‘, dealt with teenager Louise Wedderburn’s attempts to break into the fashion industry, despite her having this terrible disease.  The information byline for the show asked if the ‘notoriously image conscious fashion industry (would) accept her?’.  However, as the program progressed, it was clear to see that Louise had the tenacity necessary and had started to make clear progress towards her ideal career by gaining work placements at well recognised fashion magazines, and by starting to make her name known in the industry through her fighting spirit.

This program clearly was not about the disease itself, but about one person realising their dreams despite the disease.  As such, there was minimal background information regarding the history of the disease or of the prognosis of Fibrodysplasia Ossificans Progressiva.  Instead this program helped to raise of the profile of a dynamic young individual who, despite having this disease, is determined to make the most of her life.  The viewer was allowed access into what life is like for a person suffering this disease, both for the drawbacks and the numerous hospital visits, but also for the everyday glimpses of how you can still live your life and make a positive impact.  I would wholeheartedly recommend watching the program if you have the chance.

Perhaps the most famous sufferer of FOP is a person called Harry Eastlack (1933-1973), who bequeathed his skeleton to medical science whilst he was alive in the hope that his bones may one day help future researchers uncover a cure or help ease the pain of fellow sufferers.  Dying just short of his 40th birthday through complications arising via FOP, Harry Eastlack had became entombed within his own skeleton towards the end of his life as every joint ossified and fused completely, leaving only his lips free to move.

A photo of Harry Eastlack’s back and ribcage, with evidence of excess bone growth and ossification of the muscles, tendons and ligaments (via IFOPA).

Today researchers and medical staff at the College of Physicians in Philadelphia and the Mutter Medical Museum use his skeleton to help test and compare lab results and learn and study about the effects of FOP via his remains; Harry’s skeleton is only one of the few existing skeletons in the world with FOP and provides a very important source of knowledge, both for the medical world and the general public.

There are no known instances of FOP disease in the archaeological record, likely because it is so rare and the fact that prehistoric/historic individuals would not have likely survived as long as individuals do today with the condition.  However it is worth reading up on the disease just in case, and I would, once again, recommend watching the program.  As so often in the fields of archaeology and human osteology, we only get to investigate the bones of the dead themselves, they cannot tell us directly their lives or suffering so we must, as osteoarchaeologists, beware of what the bones can tell us.

Further sites of interest:

Anatomy of Human Dissection: An Introspection

27 Sep

It was to be the last time that we saw his body on the table.  In the intervening weeks we had come to know his features with intimacy and respect.   Outside the wind had turned fierce, whilst the clouds, a deep shade of grey and pregnant with snow, streamed across the sky as winter proper closed in.  The Medical Teaching Unit had largely emptied over the past week, the last teaching week before the Christmas break.  Only the aspiring human osteologists and palaeoanthropologists now remained and filled the cavernous light blue coloured room.  With glistening scalpels and silver probes, the last examination of our beloved participant took place.  Pairs of nervous eyes and trembling hands ran through what we had been taught.   We touched and felt the cold body as we reeled off the list drilled into us by the 12 weeks of dissection classes.  Each muscle,  its attachment; insertion; action; nerve; blood supply; ligaments and tendons, were ticked off, one by one.  Each major actor in the human musculoskeletal system was to be identified and admired.  Just as in field archaeology, as in the body.  There are layers, superficial and deep, to be uncovered and appreciated, and then to be reflected back as we investigated further.

It had taken some getting used to at first, the chemical smell and the sights of the MTU.  The individuals who had donated their bodies were to be found wrapped up on their metallic trays, waiting with eternal patience in the centre of the room.  I couldn’t help but notice the sad fact of the bodies different lengths, from adult to child.  It was a hive of activity, bristling with groups of medical students crowding around different individuals on their cold slabs.  The medical students commandeered the central space every week, as they deconstructed the body to heal it.  Tucked away in the side of the main room, we learnt about the intricacies of the fleshed body; how movement is dictated by flexion and extension of passive and active striated skeletal muscle groups.  Each week we would start with a new aspect on our adopted individual and help uncover that week’s muscle group.

The first exam had been taken some 5 weeks before, and we now stared at the second, a mere day or two away.  Our focus this time was the lower half of the body, from the pelvis down to the toes.  The almost fan-like gluteal muscles provided a staunch launching pad from which to run down the thighs, past tensor fascia latae and the iliotibial band on the lateral aspect, to curve with the sartorius on the anterior aspect, as we reached and admired the complexity of the knee joint.  As we uncovered and cleaned each section free of adipose fat, we unveiled the vastus, adductors and hamstring muscle groups.  Whilst running a discussion on what constituted the delicate femoral triangle, I couldn’t help but think of my own numerous surgeries.  Of the many times I have had a scalpel part my skin on the lateral aspect of my thighs.  That scar tissue, on my body as a permanent fixation, serves as a reminder that I too have been laid on a table, ready to be examined and explored; that ultimately, there is no difference between the living and the dead- it is just a different state of being, of matter in the universe.

We had already uncovered the startlingly array and complexicity of the upper body in previous dissection sessions.  The human body, like any living creature, is a marvelous machine developed over millions of years of evolution.  Nothing is perfect however.  Homologies from a common ancestor, ‘the same organ in different animals under every variety of form and function’, are to be found throughout the animal kingdom, and the human as a part of this, has many.  They are well documented, and I shan’t digress here.  However, it is important to note the expected variation within species and between species.  The detailed analysis of fossil hominids depends on this fundamental approach, even as new batteries of investigations are used.

And now, the week before Christmas, the main hall stood empty.  No bodies lay on their metallic tables, and there was no crowd of bustling medical students hunched over, investigating and desiccating the minutiae of life.  It was as if even the bodies had gone home for the bleak mid-winter break.  As we finished testing each other on the soleus or the gastrocnemius, we carefully de-bladed the scalpels, washed all of the tools, and placed them back inside our student dissection kits for the last time.  We silently thanked the individual’s generous bodily donation, and placed the plain cloth over the body and carefully tucked it in.  As I made my way to a nearby exit, my fellow colleagues were already outside breathing the fresh cold winter air.  As I opened the exit door I was accompanied by a lonely radio playing a mournful 1950s song.  Knowing that I would not be back in this place again, I closed it and bid the room a fond farewell.

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The University of Sheffield MSc Human Osteology program is the only UK based University that offers the teaching and education of human musculoskeletal anatomy by first hand dissection.  Other UK Universities offering Osteological Masters degrees only teach musculoskeletal anatomy in the lecture theatre.  I firmly believe that my education was enhanced by this opportunity.  At all times the people who donated their bodies to the Medical Teaching Unit were respected and treated with dignity.  The staff displayed professionalism and esteem, and encouraged us all to smile and to learn about the wonders of the human body.

Related and Further Information:

  • The Chirurgeon’s Apprentice has an interesting article on vivisection in Early Modern England, and the medical advances and reactions to this method of dissection.
  •  An article in the Lancet by Lindsey Fitzharris (2012: 108-109), author of the above blog, discusses the effects of human dissection on early modern doctors and today’s medical practitioners .  
  • Guardian article citing the difficulties of obtaining skeletons for academic study, and the difficult process of donating bodies for medical and clinical science, with quotes from Dr Tim Thompson and Dr Piers D. Mitchell
  • At the Museum of London, there is a current exhibition on ‘Doctors, Dissection and Resurrection Men‘ (until April 2013) detailing the excavation of 262 burials from Royal London Hospital with extensive evidence of dissection, along with faunal remains.  The exhibition “reveals the intimate relationship between surgeons pushing forward anatomical study and the bodysnatchers who supplied them; and the shadowy practices prompted by a growing demand for corpses” (MoL 2013).

 

Skeletal Series Part 10: The Human Leg

15 Mar

We shall continue our look at the human skeleton with the next installment of the Skeletal Series blog posts with a consideration of the leg elements.  Previously covered was the hip and we shall now cover the femur (upper leg), patella (kneecap) and the tibia and fibula (the two lower leg elements).  The evolution of the leg mirrors that of the arm, from ancient fins to rod bearing segments, and as per the arm the leg contains a single upper bone with two lower bones making up the limb ending in the quite unique foot or Pes (White & Folkens 2005: 255).

The femur is the human body’s longest and sturdiest bone that helps to take the whole weight of the body during ambulation (Schwartz 2007: 151).  The tibia is the larger of the lower leg bones and it is easier to tell it apart from its slimmer lateral partner, the long and angular fibula.  The patella is the body’s largest sesamoid bone, safely ensconced in its muscle pouch in the anterior portion of the knee.  The human knee is particularly interesting as it ‘locks’ when stood straight up and unlocks with the aid of the popliteus muscle by laterally rotating the distal femur, which helps critically stabilise the knee.

The basic bones of the human leg (Image credit: Sheri 2012).

Excavation

During excavation of the supine skeleton in-situ, the lower limb bones tend to survive well because of their structural design and bone density.  In extended burials, and dependent on burial and soil conditions, the lower limb bones are often well-preserved and relatively easy to distinguish from the rest of the body.  As always, care must be taken when excavating the soil on top of and around the lower body.  The fibula can often be found fragmented or broken due to its lateral positioning and the effect of the weight of the soil and associated tibia lying close to it (Larsen 1997).  Even in cremated or burned skeletal tissue samples, particular features and landmarks of the lower limb long bones can easily be identified, and sometimes even sided as larger fragments can sustain slightly higher temperatures and minimal warping (White & Folkens 2005).

A medieval cemetery excavation during the 2007 Brodsworth community project (Image credit: the universities of Hull & Sheffield field school).

Leg Anatomy and Elements

The lower limb in the modern human is an interestingly adapted limb to bipedal walking, and as such it has changed anatomically from our nearest cousins (the great apes) to cope with our locomotion (Jurmain et al. 2011).  In this section we’ll cover the basic gross anatomy of each bone with a more in-depth look at the knee component after.  As mentioned elsewhere (and on this blog herelong bone growth is typically through the distal metaphysis (distal border of the diaphysis of the limb) and its epiphysis through the growth plate.

Growth of the long bones in a juvenile knee joint (the femur is located proximally, with tibia distal and fibula laterally. (Image credit: Danna 2011).

Femur

The femur, as stated, is the longest limb bone with several distinctive bony elements.  It is a fairly distinct bone with a high level of robusticity and dense, compact bone due to it being the main supporting limb doing ambulation.  The head of the femur fits into the acetabulum of the hip bone (ilium, ischium and pubis bones).   Unlike the humerus and the glenoid cavity joint, it has a direct ligament attachment between femoral bone and acetabulum, the ligamentum teres, which fits it snugly from the fovea capitis depression on the femoral head into the hip joint, helping to stabilise the joint (White & Folkens 2005: 255).  It is also heavily walled with muscles, from the trunk of the torso down to the knee, with the gluteal (lateral-posterior),  adductors (medial), quadriceps (anterior) and hamstring (posterior) muscle groups acting on the bone at various points (Gosling et al. 2008).  

Main anatomical landmarks of the femur.  For further information see Hawks 2011.

The main osteological features found on the femur include the greater and lesser trochanter’s, which are found in the proximal half of the femur, just below the femoral neck.  The greater and lesser trochanter’s act as muscle attachment sites for the gluteal muscles, amongst others, and sometimes a third trochanter can been seen just distal of the lesser (White & Folkens 2005).  Directly posterior, and running down the length of the shaft of the femur, is the linea aspera, one of the main attachment points for a variety of muscles, including the vastus and adductor muscle groups.

At the proximal femoral end the linea aspera collects the spiral, pectineal and gluteal lines (White & Folkens 2005: 257).  The lateral and medial condyles mark the distal articular surface with the tibia bone of the lower limb.  Alongside the medial edge of the medial epicondyle (just above the medial condyle) lies the adductor tubercle, the insertion point for the adductor magnus muscle (Gosling et al. 2008: 260).  The femur can be easily sided as the trochanters are medial and posteriorly positioned, with the linea aspera running directly posteriorly and the adductor tubercle located medially on the medial epicondlye.  The mid-section shaft of the femur is tear shaped, with the round body in the anterior position and the top of the  ‘tear’ pointing posteriorly.

Patella

The patella is the human skeletal systems largest sesamoid bone, and can be found in the anterior muscular pouch on the knee joint, anchored by the quadriceps tendon and patellar tendon on the distal anterior femoral surface (see diagram below).  It does not attach or articulated directly with any other bone.  The patella functions to ‘protect the intricate muscles and ligaments inside the knee joint, to increase area of contact between the patellar ligament and the femur, and to lengthen the lever arm of the quadricep muscles’ (White & Folkens 2005: 270).  The apex of the patella is the most distal point of the bone, and the smooth posterior articular facet rides the ligaments and muscles located anteriorly of the distal femur.

knee joint

The complex knee joint and associated ligaments that keep the joint stable. Image credit: The Healthy Dancer.

Tibia

The tibia is a distinctly shaped bone with an proximal medial and lateral condyles, medial and laterally intracondylar eminence’s (set posteriorly on the superior surface), an anterior proximal tibial tuberosity, the curved ‘tri-blade’ of the body (anterior, medial and posterior crests, with the medial malleolus marking the distal extremity of the bone (White & Folkens 2005: 273-79).  The landmarks on the tibia represent muscle origin and insertion points, such as the soleal line on the posterior aspect of the proximal tibia, which represents the soleus muscle origin.  The tibia is connected to the laterally positioned fibula with a strong interosseus membrane connecting the two throughout the length of the fibula, with articulations at the proximal and distal segments of the tibia (Gosling et al. 2008: 277).  Distally, the tibia articulates with the talus, the first tarsal bone of the foot.  To easily side the tibia, the malleolus is located on the medial distal aspect of the tibia, and the tibial tuberosity represents the anterior facing proximal end of the bone.

Labelled Tibia and Fibula.

The main anatomical landmarks of the right tibia and fibula, with the anterior position on the left and the posterior on the right hand side. (Image credit: Wikipedia 2012).

Fibula

The fibula is the thinner of the two lower legs bones, and does not bare any substantial weight (White & Folkens 2005).  It’s primarily importance is providing the lateral border of the ankle joint, with which it articulates with the calcaenous bone.  The head of the fibula, located superiorly, can be easily complicated with the distal malleolar articular surface, and to add to the woes of identification, the body of the fibula, without the proximal or distal segments, is nearly impossible to identify because of its irregularity.  The interosseous crest is located medially, and serves as the attachment for the interosseus membrane which spans between the length of the tibia and fibula.  To side an intact fibula quickly, use the posterior facing malleolar fossa, which can be found on the distal articular surface of the fibula.  The fibula has also been used as marker of sex (Sacragi & Ikeda 1995) and although this method is rarely used, it could be useful in a forensic or archaeological context where the skeletal remains may be limited.

Further Information

  • Although not mentioned here, please take the time to get associated with the fleshy articular pads between the femur and tibia (be aware as this is a fleshed photo).

Bibliography

Gosling, J. A., Harris, P. F., Humpherson, J. R., Whitmore I., & Willan P. L. T. 2008. Human Anatomy Color Atlas and Text Book. Philadelphia: Mosby Elsevier.

Hawks, J. 2011.  Femur: major landmarks and how to side it. From www.johnhawks.net. Accessed 2012.

Jurmain, R. Kilgore, L. & Trevathan, W.  2011. Essentials of Physical Anthropology International Edition. London: Wadworth.

Larsen, C. 1997. Bioarchaeology: Interpreting Behaviour From The Human Skeleton. Cambridge: Cambridge University Press.

Roberts, C. & Manchester, K. 2010. The Archaeology of Disease Third Edition. Stroud: The History Press.

Sacragi, A & Ikeda, T. 1995. Sex Identification From The Distal Fibula. International Journal of Osteoarchaeology. 5: 139-143. (access required).

Schwartz, J. H. 2007. Skeleton Keys: An Introduction to Human Skeletal Morphology. New York: Oxford University Press.

White, T. & Folkens, P. 2005. The Human Bone Manual. London: Elsevier Academic Press.

Skeletal Series Part 9: The Human Hip

22 Jan
In this post I shall be discussing and looking at the three main elements that make up the human pelvis (or the pelvic girdle, a homology to the shoulder girdle).  The bones that make up the pelvis are the Ischium, Ilium & the Pubis.  The Sacrum has been discussed in an earlier post on the spine.  During the development of the hip, these three elements remain singular, fusing together during adolescence to become one single unit during early maturity to become the Os Coxa (White & Folkens 2005: 246).

The main elements in the human hip, and as a whole Referred to as the Os Coxa. NB acetabulum faces laterally.

The hip is a fantastic wealth of skeletal knowledge.  The two most basic and fundamental traits of the person, the age and biological sex of the individual, can be found in articles by Brooks & Suchey (1990) and by Patriquin et al. (2005), which both use morphological features of the pelvis to estimate sex and age of the individual under study.  Many muscles also insert and attach along the borders, rims and edges of the pelvis, especially anchoring those that are key in movement during bipedal locomotion (Schwartz 2007: 147).  The hip, and its component parts, are most distinctive in shape and size.  Odd looking, hard to figure out at first, and looking like nothing else (a top heavy hourglass is one view), the Os Coxa can can be hard to identify and orientate, especially in smaller fragments.

Juvenile ilium (top), ischium (bottom right) and pubis (bottom left) (Image credit: Bone Clones 2006).

Excavation
Unfortunately during excavation, the first thing that the pick ax, spade or trowel is likely to hit is the most anterior part of the hip, the pubic symphysis, as in most human burials the body lies prone and face up, in a supine burial (see Brothwell: 3 for other burial positions).  This can lead to destruction of this joint, which can lead to loss of information on age and sex of the individual.  However, during normal inhumation excavation the grave cut can be clearly distinguished, and a pattern of working from top to bottom or bottom to top can help limit the amount of damage during excavation (White & Folkens 2005).

The author excavating a Medieval skeleton in Germany in 2011. Note the damaged anterior aspect of the Pubic Symphysis, which is outlined in red.

Pelvic Anatomy and Elements:
Acetabulum
The acetabulum  makes up the socket to receive the head of the femur (thigh), and is equally made up of a portion of the three elements of the hip which fuse during early adolescence.  This joint is necessarily much more stable then the non-weight bearing shoulder joint- it is much deeper, has the ligamentum teres (a ligament that attaches to the femoral head and the hip) and is covered by much stronger and denser musculature (White & Folkens 2005: 246).  As the main weight bearing joint, the bone is also much denser with thicker cortical bone.
Ilium
The ilium is the largest of the three parts of the os coxa, and sits superiorly above the ischium and pubis, and it is often described as ‘blade like’ (Schwartz 2007: 148) as it is a thin but strong plate of curved bone.  On the lateral side of the blade, three gluteal lines (anterior, inferior & posterior) are visible which are the muscle attachment sites for the large gluteal muscles.  The main landmarks along the upper ridge is the iliac crest, which can be felt on yourself, and begins anteriorly with the anterior superior iliac spine and ends in the posterior superior iliac spine (White & Folkens 2005: 247).  The auricular surface of the medial ilium articulates with the sacrum (and is a very useful age estimator- Buckberry & Chamberlain 2002).  The greater sciatic notch is also generally a good indicator of the biological sex of the individual.

Anatomical landmarks on the right hip (Image credit: Pearson Education 2010).

Ischium
The ischium is the butt bone, literally the bone which takes the weight whilst we are sitting on a chair!  The key features of this element of the hip is that a lot of muscles attach to the posterior ischial tuberosity.  The ischial tuberosity muscle attachments include the origins of the hamstring muscles (semimembranosus, semitendinosus, adductor magnus & biceps femoris) (White & Folkens 2005).  Alongside the pubic bone, the ischium also includes the obturator foramen, a gap (in life covered by a membrane) where a number of internal gluteal muscles converge and provide stability for the hip.
Pubis
The pubic bone makes up the anterior part of the hip as a whole and includes a cartilaginous joint, just above the genitalia in living individuals.  The pubic symphysis, as this joint is called, is also a good indicator of biological sex because of the shape below it (the  pubic arch) and also age because of age related changes in the bony surface of the pubic symphysis (Schwartz 2007: 230).  The pubic bone also includes a superior and inferior pubic ramus, literally the corpus of the bone, which help support numerous muscle attachments, namely the adductors (adductor brevislongus & magnus) of the medial compartment of the thigh.

The  major landmarks of the pelvic bones in anatomical position.

Discussion

For the discussion on the hip we shall talk about septic arthritis (SA).  SA is mostly common in the hip and knee, and rarely presents in the elbow or shoulder.  Although it is rare in the archaeological record, it is nonetheless recorded in a number of examples (i.e. Yukon individuals in the Natural Museum of National History in Washington, US), and it pays to be able to recognise it (Roberts & Manchester 2010: 154).  The condition is fairly uncommon, and the aetiology of SA is when an infection reaches a joint, normally through one of three means- i) the haematogenous route (most common), ii) a penetrating injury or iii) its spread from metaphysis (Marsland & Kapoor 2008).  The bacteria, or germ, normally infects the synovial fluid which may be inflamed from disease or trauma, and ‘proliferation of bacteria cause an inflammatory response by the host with numerous leucocytes migrating into the joint’ (Marsland & Kapoor 2008: 136).

Main outcome of septic arthritis (Image credit: http://www.aidmyarthritis.com).

At this point the variety of enzymes and breakdown products that are produced helps to damage the articular cartilage very quickly, and if left will produce permanent damage (Waldron 2009: 89).  The prognosis is good if treated promptly, however in the archaeological record this is quite unlikely due to the high risks of re-infection and complications such as joint destruction, avascular necrosis (mostly at the hip) & the ‘seeding of infection’ to other places (Marsland & Kapoor 2008: 137).  Again, the diagnosis of septic arthritis in the archaeological record is hindered by confusion with similarities to tuberculous infection, and difficulties in diagnosing multiple diseases that may present themselves on any one individual (Roberts & Manchester 2010: 154).  In the hip, the surface and surrounding area (lunate surface) of the acetabulum would be highly damaged, with a rough appearance and feeling as the bony lytic destruction took hold (Waldron 2009).

Bibliography

Brooks, S. & Suchey, J. M. 1990. Skeletal age determination based on the os pubis: a comparison of the Acsádi-Nemeskéri and Suchey-Brooks methods. Human Evolution 5– N.3: 227-238.

Brothwell, D. R. 1981. Digging Up Bones: The Excavation, Treatment and Study of Human Skeletal Remains.  Ithica: Cornell University Press.

Buckberry, J.L. & Chamberlain, A.T.  2002.  Age estimation from the auricular surface of the ilium: a revised methodAmerican Journal of Physical Anthropology 119: 231-239.

Larsen, C. 1997. Bioarchaeology: Interpreting Behaviour From The Human Skeleton. Cambridge: Cambridge University Press.

Marsland, D. & Kapoor, S. 2008. Rheumatology and Orthopaedics. London: Mosby Elsevier.

Mays, S. 1999. The Archaeology of Human Bones. Glasgow: Bell & Bain Ltd.

Patriquin, M.L., Steyn, M. & Loth, S.R. 2005.  Metric analysis of sex differences in South African black and white pelvesForensic Science International 147: 119-127.

Roberts, C. & Manchester, K. 2010. The Archaeology of Disease Third Edition. Stroud: The History Press.

Schwartz, J. H. 2007. Skeleton Keys: An Introduction to Human Skeletal Morphology. New York: Oxford University Press.

Waldron, T. 2009. Palaeopathology: Cambridge Manuals in Archaeology. Cambridge: Cambridge University Press.

White, T. & Folkens, P. 2005. The Human Bone Manual. London: Elsevier Academic Press.

Skeletal Series Part 7: The Human Arm

30 May

In this post we shall focus on the main bones located in the arm.  They are the Humerus, Radius & Ulna.  The previous post on the shoulder elements (Scapula & Clavicle) can be found here.  It should be noted that the bones discussed  in this post, known as the forelimb, are the homologs to the bones in the leg, the hind limb.

The Human Arm, And The Bones Under Discussion

Articulation of arm with the distal humerus and proximal radius and ulna making the elbow joint (Image credit: Wikipedia 2011).

Excavation

As noted in previous Skeletal Series posts care should be taken with excavating human remains, and the maxim that ‘context is everything’ should be well noted with detailed plans of the in-situ remains made.  It is likely that some damage will have occurred to the smaller ulna and radius as they are more fragile then the larger and denser humerus bone.  A record of the condition of the bones should be made, alongside what contextual information is available (Mays 1999, White & Folkens 2005).

Arm Anatomy & Function

The humerus articulates proximally with the scapula and clavicle, as discussed in the last entry (See diagram below).  The distal humerus articulates with the proximal radius and ulna head.  This articulation makes up the elbow, which will be discussed in detail below.  At the distal end of the radius and ulna the carpals are located, which make up the wrist.  These, alongside the other elements in the hand, will be discussed in the next Skeletal Series post.

The individual brachium and antebrachium skeletal elements and major skeletal landmarks, as seen in articulation with the full limb (image credit: Wikipedia 2011).

The function of the forelimb is to provide a rigid limb to help hold, grab and move surfaces and objects.  The shoulder girdle and arm bones have moved away from our evolutionary history of weight-bearing limbs, and have become essential in helping humans to manipulate and move objects with astounding dexterity (Jurmain et al 2011).

Elbow Joint

The elbow joint (image credit: CK-12).

This joint in particular is important to understand as it is a key hinge joint.  The diagram below helps to mark out the distal humerus with the proximal radius and ulna in articulation.  The elbow is one of the strongest points of the body in terms of bone hitting strength.  The two main movements of the elbow are flexion and extension of the humerus and ulna, alongside the pronation of the radius and ulna in turning the arm over (White & Folkens 2005).  The joint itself has a large synovial membrane that protects the articulation points of the bone, whilst the main muscles involved are the Brachialis & Brachiaoradialus (at the anterior side) and the Triceps Brachii & Aconaeus towards the posterior side.  The lateral and medial muscles are the Supinator and Extensor muscles, alongside the Flexor muscles and Flexor Carpi Ulnaris muscles (White & Folkens 2005, but also here).

Anterior elbow joint in articulation, highlighting the major skeletal landmarks of the three bones that make up the joint. Image credit: here.

The Humerus

The humerus is the largest bone in the upper body, and ‘compromises of a proximal end with a round articular head, a shaft, an irregular distal end’ (White & Folkens 2005: 203).  It articulates with the Glenoid cavity (or fossa) of the scapula, and as mentioned, the proximal radius and ulna at the distal end.  The humerus head faces medially, whilst the surgical (or anatomical) neck is the groove that encircles the head for the attachment of the joint capsule (White & Folkens: 203-4).  Both the Greater and Lesser Tubercle are muscle attachment eminences that help move and rotate the upper arm.  On the Greater tubercle (the more posterior and large of the tubercles) rugosities for the insertion of the rotator cuff muscles are round, which help in rotation and adduction and abduction of the arm (White & Folkens 2005).

Main skeletal landmarks of the humerus (click to enlarge). Image credit: Google 2011.

The Shaft of the humerus is variably triangular in section, going from more cylindrical at its proximal end to more triangular in shape towards the distal end (Larsen 1997).  The Deltoid tuberosity is an important feature located on the lateral side of the shaft.  It is the insertion site of the deltoideus muscle, and is recognised by its roughened appearance.  Towards the distal end of the humerus we have several key features that are easily identifiable in recognising this as an upper limb element.

The Olecrannon Fossa is the largest of three hollows located posteriorly at the distal end, and accommodates the olecrannon process of the ulna during forearm extension.  The Capitulum is the rounded eminence that forms the lateral portion of the distal humeral surface, and it articulates with the head of the radius (White & Folkens 2005: 211).  The Lateral and Medial Epicondyle are the non articulating projections of bone, the medial is more prominent than the lateral epicondyle.

The humerus is relatively easy to recognise by the certain features picked out above, but parts can be confused with the tibia and femur.  With the femur, the head has a distinct depression called the Fovea Capitis whilst the humerus lacks this feature (Mays 1999).  The humeral shaft is smaller and less triangular than the tibial shaft.  When siding remember that the olecrannon fossa is posterior and the medial epicondyle is larger, and the humeral head faces medially.  The deltoid tuberosity is found laterally (White & Folkens 2005: 214).

The Ulna

The Ulna is the longest and thinnest bone of the forearm, and articulates proximally with trochlea of the humerus and head of the radius.  Distally, it articulates with the ulnar notch of the radius and an articular disk that separates it from the carpals.  The Olecrannon of the ulna is located on the most proximal part of the ulna; it is the insertion point for triceps brachii muscle.  The Trochlea Notch articulates with the trochlea articular surface of the humerus.  The Coronoid Process is the ‘anterior beak shaped projection at the base of the semilunar notch’ (White & Fokens 2005: 219).  The Radial Notch  is the small articular surface for the radius, and is located along the lateral side of the coronoid process.  The Radial Articulation (Ulna Head)  is the distal, lateral round articulation that conforms to the ulna notch on the radius.  The distal and proximal ends of the ulna are fairly distinctive and indicative of the element, however as White & Folkens (2005) and May (1999) point out, the shafts could be mistaken for radial or fibular shafts.

The ulna and the radius and their associated skeletal landmarks, click to enlarge. Image credit: Wikipedia 2011.

The Radius

The radius is a relatively small bone and shortest of the three in the forelimb.  Its name was gained for the action it goes through as the ‘turning movement about the capitulum of the humerus’ (White & Folkens 2005: 214).  At the proximal end it articulates with the humerus and medially with the ulna on both proximal and distal ends, whilst also distally it articulates with two carpal bones of the wrist.

The Head is a round articular structure at the proximal end of the radius, and as stated above articulates with both the humerus and ulna.  The Neck is a slender segment between the head and the radial tuberosity.  The Radial Tuberosity is a blunt rugged structure on the anteromedial site of the proximal radius that marks the insertion for the biceps brachii muscle (Mays 1999).  The  Styloid Process is a sharp projection located on the lateral side of the distal radius whilst the Ulnar Notch is a concave articular hollow on the medial corner of the distal radius.

Discussion: Wrist Fracture

Colle’s fracture is a break at the distal end of the radius and ulna that results in a ‘dinner fork deformity‘ with dorsal angulation, and displacement of the fracture with radial angulation.  The counterpart to this is Smith’s fracture which is the same but the fracture is displaced in the opposite direction, ie palmar (Marsland & Kapoor 2008: 96).

Smiths fracture highlighting the displacement of the distal radius. Image credit: Wikipedia 2011.

These type of fractures often occur because of trips or falls onto outstretched hands, as an automatic safety device by the body.  In modern contexts they also happen in a variety of sport environments.  These types of breaks are often easy to treat with splints and plaster casts, although they sometimes require surgery to correct the breaks and/or angles.  The patients can often be left with a visible deformity, but likely without any pain whatsoever (Marsland & Kapoor 2008: 96).  In archaeological examples these type of fractures can be found in any number of contexts or cultures.  It is important to note that, as Larsen (1997) says, many human cultures’ skeletal series often exhibit these breaks, and it can shed light into pathways of differing lifestyles.  Larsen also notes that whilst there is a large osteological literature on injuries in comparison to more population based studies which would help to highlight inferences on accidents and conflict in both historic and prehistoric societies (1997: 109).

Further Information

Bibliography

Jurmain, R. Kilgore, L. & Trevathan, W.  2011. Essentials of Physical Anthropology International Edition. London: Wadworth.

Larsen, C. 1997. Bioarchaeology: Interpreting Behaviour From The Human Skeleton. Cambridge: Cambridge University Press.

Marsland, D. & Kapoor, S. 2008. Rheumatology and Orthopaedics. London: Mosby Elsevier.

Mays, S. 1999. The Archaeology of Human Bones. Glasgow: Bell & Bain Ltd.

Roberts, C. & Manchester, K. 2010. The Archaeology of Disease Third Edition. Stroud: The History Press.

Waldron, T. 2009. Palaeopathology: Cambridge Manuals in Archaeology. Cambridge: Cambridge University Press.

White, T. & Folkens, P. 2005. The Human Bone Manual. London: Elsevier Academic Press.

Skeletal Series Part 5: The Human Rib Cage

6 May

As we covered the vertebrae in the previous post in the skeletal series, we shall move on to the last elements in the axial skeleton (bar the clavicle and scapula in next post).  The elements of the appendicular skeleton will follow shortly.

Excavation

As before, great care must be taken when excavating the ribs.  I have carried out micro-excavation of juvenile remains, (when I volunteered at Humber Field Archaeology) that consisted of the vertebrae, half of the ribcage and parts of the pelvis in-situ, and it took a while.  During excavation of human remains on site, it is very unlikely that the rib cage will be in its natural anatomical position.  Due to the soil and weight of the earth above the body, and the movement in the intervening period between burial and excavation, the ribs are likely to be broken and misplaced.  As always keep a look out for finer skeletal finds.

The Rib Cage

The focus of this post will be the sternum, which is made up of the Manubrium, Corpus Sterni (or Gladiolus) and the Xiphoid Process alongside a look at the ribs, all of which help to form the rib cage.  It is necessary to note here that variation in the number of ribs, as of the vertebrae discussed previously, can differ in people and in archaeological populations (Mays 1999: 15).  The function of the rib cage, as the main upper part of the torso in the human body, is to protect the vital organs that lie within the protective enclave of the ribs.  They include the majority of the torso organs such as the heart, liver, lungs, kidneys and partially the intestines.  The rib cage also helps breathing by the function of the intercostal muscles lifting and lowering the rib cage, aiding inhalation and exhalation.  The ribs are attached dorsally to the vertebrae, with articulating facets for the tubercle end of the ribs for the thoracic vertebrae (White & Folkens 2005).

Main anatomical elements of the rib cage. (Image credit: Wikipedia 2011).

Rib Cage Anatomy, Terminology and Elements

The number of ribs present in the typical human skeleton is of 12 paired rib elements (a total of 24 altogether). Ribs project from proximal articulating facets with thoracic vertebrae, slant forward, and depending on the rib pair under consideration, articulate at the distal end with either the sternum, hard cartilage or ‘float’ freely (Jurmain et al 2011).  Ribs usually increase from size from rib 1 to rib 7, and decrease in size from rib 7 to rib 12 (White & Folkens 2005: 185).

Posterior view of ribs and their articulating vertebrae partners. (Image credit: Wikipedia 2011).

The Upper 7 ribs on each side of the cage connect distally directly to the sternum via cartilage, whilst the 8th, 9th and 10th ribs connect indirectly to the sternum.  The last 2 ribs are often called ‘floating’ ribs because they have ‘short cartilaginous ends that lie free in sides of the body wall’ (White & Folkens 2005: 181).

The basic landmark anatomy of a rib includes the head, neck, tubercle which articulates with the thoracic vertebrae & the long shaft of the rib.  In the picture below the head of the ribs are medial whilst the sternal ends are lateral.  The side that is superior is called the cranial edge, whilst the inferior is called the caudal edge.  It can be fairly easy to side a loose or partial rib as the Cranial edge is fairly thicker and blunter when compared to the grooved and sharp caudal edge (White & Folkens 2005: 192).

The rib cage laid out from 1st to 12th ribs, note the size and shape morphology. Occasionally an individual will have only 11 paired ribs or may have an extra pair, this is natural variation. (Image credit: Shutterstock).

Distinctive Rib Cage Elements

  • The 1st rib is most unusual and can usually be identified the easiest.  It is particularly blunt, broad and thick, as well as this it has no caudal groove (Roberts & Manchester 2010).
  • The 2nd rib serves as an intermediary to the 1st and 3-9th more regular ribs.  It has a large tuberosity for the serrator anterior muscle half way along its length (White & Folkens 2005: 187).
  • The 11th rib lacks a tubercle and the sternal end is often pointed.
  • The 12th rib is shorter then the 11th rib and may be even shorter then the 1st rib.  It lacks the angle and costal groove, and is often easy identifiable (May 1999).

Sternum

As stated the sternum is made of 3 individual bones, those of the manubrium, corpus sterni and the Xiphiod Process.  As made clear by the diagrams below, there are 7 facets located laterally for the anterior of the ‘true’ ribs alongside the corpus sterni and manubrium.  The sternum is composed of these three elements in adulthood but develops from 6 segments (White & Folkens 2005: 181).

The manubrium is the thickest and squarest part of the sternum bones and should be easily identifiable as such.  At the superior corners there are clavicular notches located, which articulates with the right and left clavicles.  The clavicles and scapula help to form the shoulder girdle and will be discussed in the next post.

The three individual elements of the sternum, with the manubrium (proximal), corpus sterni (centre) and xihoid process (distal) highlighted. (Image credit: Wikipedia 2011).

Lateral view of sternum elements with the individual rib facets highlighted. (Image credit: Wikipedia 2011).

The corpus sterni is rather thin in comparison to the manubrium, and it is often said to be ‘bladelike’.  Again, costal notches are present as seen in the above picture.  They cater for ribs 2-7 (Mays 1999).

The xiphoid process can be found inferior to the corpus sterni but, depending on the age of the person involved, may not be found in archaeological samples.  The process shares the seventh costal notch.  This bone is often highly variable in shape, and is late to ossify (White & Folkens 2005: 184).

A Pre-contact Peruvian Case Study

The site of Pacatnamu, in the Jequetepeque River valley on the northern Peru coast, provides a site where mutilated human remains and contextual information has been unearthed (Larsen 1997: 137).  At this Moche site (100-800 AD), evidence has been found of executed captives who were thrown into a trench at the bottom of an entrance to a ceremonial precinct (Verno 2008: 1050).  The skeletal group found & studied was composed of 14 adolescent and young adult males, who were recovered from 3 superimposed layers at the site.  The superimposed layers were indicative of 3 distinct burial episodes (Larsen 1997: 137).  From the evidence on the skeletal elements, it seems that weathering took place after death but before burial.  The evidence is backed up by the palaeoenvironmental remains of the presence of the pupal cases of muscoid flies (Verano 1986).

Pacatnamu mass burial archaeological site and the second layer (Image credit: Verano 2008).

It seems that the display of the decomposing bodies, together with a lack of a proper burial, was clearly intentional.  In the topmost layer of the burial episodes, multiple stab wounds were found on both the vertebrae and rib elements.  This pattern is broken by the bottom and middle layer where the pattern is more towards decapitation or throat slashing as evidence by cutmarks on the cervical vertebrae (Larsen 1997: 137).  Of particular interest is the evidence of five individuals from the middle and lower deposits that have bisected manubriums with evidence of fractured ribs, which is suggestive of the chest cavity being opened forcibly (Verano 1986).

Larsen (1997: 137) remarks that on the ‘basis of the age distribution, sex, and evidence of healed and unhealed injuries (rib fractures, depressed cranial fractures), Verano (1986) speculates that they were war prisoners’.   The conclusion is well supported from the cultural representations in the art and architecture of the Moche culture.  Many cultures throughout the world made, and continue to make, sacrifices of various kinds; in particular it is thought that for pre-contact South American cultures human sacrifice represented ‘the most precious form of sacrifices, and seems to have been reserved for particularly important rituals and events’ (Verano 2008: 1056).

It has also been noted that the capture and killing of enemies was a common practise in communities in pre-contact South America.  Such killings can also incur within ritual presentations and displays.  There are many such examples throughout South American, and indeed throughout the Americas (Teotihuacan, Punta Lobos, Sipan) (Verano 1986).  A careful consideration through the integrated studies of the archaeological sites, bioarchaeological study of the human material, together with careful ethnographic comparisons, can help to understand the processes and results of human sacrifice in South American cultures.

Further Information

Bibliography:

Jurmain, R. Kilgore, L. & Trevathan, W.  2011. Essentials of Physical Anthropology International Edition. London: Wadworth.

Larsen, C. 1997. Bioarchaeology: Interpreting Behaviour From The Human Skeleton. Cambridge: Cambridge University Press.

Mays, S. 1999. The Archaeology of Human Bones. Glasgow: Bell & Bain Ltd.

Roberts, C. & Manchester, K. 2010. The Archaeology of Disease Third Edition. Stroud: The History Press.

Verano, J. W. 1986. ‘A Mass Burial of Mutilated Individuals at Pacatnamu‘. In C. B. Donnan & G. A. Cock. (eds.) The Pacatnamu Papers. 1. pp.117-138. Los Angeles: Museum of Cultural History, University of California.

Verano, J. W. 2008. ‘Trophy Head-Taking and Human Sacrifice in Andean South America. In H. Silvermann & W. Isbell.(ed.) Handbook of South American Archaeology. pp.1045-1058. Los Angeles: Springer.

White, T. & Folkens, P. 2005. The Human Bone Manual. London: Elsevier Academic Press.

Gough’s Cave Skull Cups

9 Apr

The surgery went very well, and I’m glad to be out of hospital so soon.  As I entered the house again, my eyes fell greedily upon the latest edition of the British Archaeology magazine.  An article that caught my eye in particular was the latest developments concerning the various excavations, and new modern scientific investigations analysis at the Upper Palaeolithic site of Gough’s Cave located in the Mendip Hills, Somerset, southern England.

It has turned out that the cave has the earliest directly dated human skull cups.  This was reported in the media a few months ago, but now an in-depth article has come out on the online PLoS ONE journal.  The 2011 article, written by Silvia M. Bello, Simon A. Parfitt and Chris Stringer, can be found here and it is open access.

Palaeogeography At The Time of use of Goughs Cave (Figure 1, Bello et al. 2011).

The Upper Palaeolithic Site of Gough’s Cave

Now, this is big news.  The site of the butchered animal and human remains is dated to the Magdalenian period of the Upper Palaeolithic, around 14,700 BP (BP simply stands for Before Present) during the end last of the glacial period (Last Glacial Maximum).  The artefacts that have been found in this particular period at Gough’s Cave include flint tools, carved reindeer antler and mammoth ivory; a particular key find is the reindeer antler baton, a fine example of the craftmanship of the humans that used to live and roam this area.

Now the finds we are most concerned with are the evidence of the defleshing of the human remains, and the very probably use of human skulls as drinking vessels.  According to the articles stated above, the human remains were found with fauna including (in descending commonest order) wild horse, red deer, wolf, brown bear, lynx, saiga antelope, arctic fox and arctic hare (Stringer Et al, in BA magazine 2011:16).  The animal remains showed evidence of butchery, in accordance with using the flesh for food.  The co-mingled human remains, mostly cranial elements with post cranial elements also showed butchery marks, and do not seem to be deliberately buried.

A selection of the human cranial elements found, highlighting the breaking and fracturing of the cranial elements during reshaping (Source: Natural History Museum).

Human Cranial Remains and Modifications

The remains subjected to new scientific analysis included 41 elements, 37 from skulls and the rest from mandibles (lower jaw).  From the study of remains it has been suggested that they represent at least 5 individuals, including a young child, two adolescents, a young adult and an older adult (Stringer et al 2011: 19).  There were three complete mandibles alongside three skulls caps present (see above).

Although it had been suggested from earlier excavations, it is now thought that the bones did not suffer much from post-depositional effects (ie weathering or trampling).  Many of the elements have evidence of stone cut marks; most were done by slicing, some chopping but signs of scraping were seen as rare.  The skulls had less evidence of percussion marks whilst cut marks were particularly evident.  Importantly they showed no sign of fire damage (such as colour changes or flaking) and all cuts are ectocranial (Bello et al 2011).

Highlighting the main points of reshaping of the human crania (Figure 8 in Bello et al. 2011).

Carefully placed ectocranial percussion marks on the vault of the crania (Source: Natural History Museum).

The processing of the head can be clearly discerned:

A) The head was detached from the body, probably whilst the body was either frozen or in the grip of rigor mortis.  Cuts at the base of the skulls and on the cervical vertebrae indicate this took place shortly after death.

B) The mandible was removed next, evidence is seen by post-mortem scratches on teeth of both mandible and maxilla alongside percussion fractures (Bello et al 2011).

C) The major muscles of the skull were removed next (Temporalis & Masseter muscles in anatomical position) alongside the removal of the lips, ears, tongue, and the possible extraction of eyes and cheeks.

D) Cut marks along the parietal and occipital elements indicate scalping as well.

E) Finally, ‘the face and base of the skull was struck off with minimum damage to the vault, and the broken edges were chipped away to make the more regular’ (Stringer et al 2011).

Key Points

Evidence for cut marks on human bones in the Magdalenian period have also been found in the Rhine Valley in Germany, Dordogne area in France.  Sites such as Le Placard in Charente & Isturitz in Oyrenees-Atlantiques (see above location map), both in France have evidence for similar skull modification and processing.  Strikingly at Isturitz, one example even has carvings of animals in the skull elements.

However, as pointed out in an earlier article on cannibalism, post cranial elements found (including metatarsals with evidence of being chewed by humans) are thought to be an example of ‘nutritional cannibalism’, even with the large amount of faunal remains co-mingled with the human remains.  The slicing marks present on these post cranial elements are consistent with the striking of ‘green’ (fresh) bone.  An interesting experimental archaeological test involved two researchers having their students chew fresh sheep and  pig bones.

This was carried out in order to test if the bite marks found were similar to bite marks on human metatarsal and radius elements found, amongst other bones (Fernandez-Javlo & Andrews 2011).  The results helped to provide evidence that the chewing marks on the human bones (including a distal rib fragment) were probably caused by human teeth themselves.

Rib chewing-archaeology style.  In experimental tests archaeologists found that volunteers chewing ribs replicated the marks made on archaeological material human rib samples at Upper Palaeolithic sites (Fernandez- Jalvo & Peters 2011).

As stated above, the skull elements was treated remarkably different with careful processes present.  There was a distinctly high number of cut marks on the cranial elements present.  Alongside this, a lack of trauma indicates that this is not for mutilation purposes, as seen at some American sites (Stringer et al 2011: 20/Larsen 1997).  At sites where nutritional cannibalism has been documented, the skull is often fractured and broken in aiding access to the brain tissues within.  At Gough’s cave, the skulls have been carefully prepared with flints and carefully processed.

This hints at possible uses of the skull-caps as containers for liquids or holders for other objects.  Ethnographic and historical sources have pointed to various cultures preparing and using human skulls as containers, war trophies or as libation instruments.  Classically, Herodotus portrayed the Scythians as people who drank from the skulls of their enemies, whilst in ‘Buddhism human skull bowls have been used as libation vessels.  In India, the use of skull cups seems to be still practiced by the Agori sub-sect’ (Stringer et all 2011: 20).  Very interestingly, the article by Bello et al (2011) remarks that there are few archaeological finds for skull-caps, in consideration of the wide temporal and geographical spread of ethnographic and historical evidence.  One example is the Neolithic site at Herxheim in Germany, previously discussed in a blog post by Kate Brown.

In conclusion, the Gough’s Cave skulls-cups have been securely dated, and are the only ones found so far in the British Isles.  The mystery still remains why they took part in this painstaking process.

Bibliography

Bello, S. M. Parfitt, S. A. & Stringer, C. B. 2011. ‘Earliest Directly Dated Skull-Cups‘. PLoS ONE. (Open Access Article).

Bones Don’t Lie. 2011. Cheddar’s Cranial Cups.  Blog Site.

Fernandez-Jalvo, Y. & Andrews, P. 2011. When Humans Chew Bones. Journal of Human Evolution. 60 (1): 117-123.

Larsen, C. 1997. Bioarchaeology: Interpreting Behaviour From The Human Skeleton. Cambridge: Cambridge University Press.

Stringer, C. B. et al. 2011. Gough’s Cave, SomersetBritish Archaeology. May-June.

Guest Blog: ‘Cannibalism In Archaeology Part 1: Recognition and Debate’ by Kate Brown.

12 Mar

Kate Brown is a current archaeological undergraduate student at the University of Sheffield.  Her research interests include Osteology, Zooarchaeology, Mesoamerican archaeology, and Scandinavian archaeology alongside the study of funerary rituals in human culture.

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Cannibalism in Archaeology

Cannibalism is generally defined as the conspecific consumption of human flesh (White 1992). It is often used to support perceptions of savagery or primitiveness; however, the reasons for cannibalistic activity are often complex, and indicative of a basis in more than simply hunger, with evidence for this based across a long time period around the world (Hogg 1958).

A Still From Cannibal Holocaust (1980)

There are two major classifications of cannibalism; exocannibalism, the eating of persons outside the cultural or social group, and endocannibalism, where members within the social or cultural group are consumed by other members (White 1992). These can further be broken down into the respective reasons behind the act of cannibalism, or the method of consumption:

Survival cannibalism – Also referred to as obligatory or emergency ration cannibalism. Actual or perceived starvation leads to cannibalistic consumption.

Aggressive cannibalism – Consumption of enemies. Can be interpreted as a form of reveng

Affectionate cannibalism – Consumption of friends or relatives. Thought to ‘keep them close’.

Ritual cannibalism – Also known as ceremonial cannibalism. The consumption of human flesh as a part of spiritual belief or ritual undertaking.

Gastronomic cannibalism – Cases of cannibalism that are neither starvation nor ritually motivated.

Auto-cannibalism – self consumption

How is it Recognised?

 
 

Hammerstone abrasions from impact (White 1992, 152)

In an archaeological context, cannibalism can be very difficult to recognise. A majority of the following archaeological standards must be met to prove the presence of cannibalistic consumption at a site (Villa et al. 1986):

–          Skull modification in order to expose the brain

–          Facial mutilation

–          Evidence of cooking, including burnt bone and fragment end polishing, which is a result of cooking in course  ceramic pots

–          Dismemberment or butchery marks. Similar to that seen on animal remains on the site if present

–          Pattern of missing elements. Post processing discard again similar to the treatment of animal bones if present

–          Green-stick splintering of long bones. This facilitates the extraction and consumption of bone marrow, which is highly nutritious

–          Cut marks

–          Bone breakage

–          Anvil and hammerstone abrasions

–          A significant number of missing vertebrae

Shaft breakage types (White 1992, 135)   Cutmarks on front of skull (White 1992, 170)

The Cannibalism Debate

When discussing cannibalism, the argument against such interpretations cannot be ignored. As well as the evidence and interpretations supporting cannibalism, there are, as always, other schools of thought.  Because archaeological evidence of cannibalistic activity is so varied and often circumstantial, this has been used to discredit any interpretations of cannibalism. Paul Bahn (1990) is well known for his work on cannibalism, and scepticism of interpretations of such activity at a site. Even with a protein only occurring in humans being found in a human coprolite at the Anasazi site of Mancos, in the South West of the USA (Whittell 1998), Bahn remains unconvinced.

Most opposition stems from the reliability of the evidence, both archaeological and ethnohistorical.

Cannibalism in Brazil described by Hans Staden (1557)

Because it is so circumstantial and subject to interpretation, it can be seen as inaccurate to derive interpretations of cannibalism from. Especially in ethnohistorical accounts of cannibalism, prejudices and the desire to promote themselves above ‘savages’ are relatively clear, and this is used to discredit them as an archaeological source (Arens 1979). Some have argued that this completely removes them from being used in terms of research into cannibalism, because such biases could have caused them to fabricate stories of the natives in order to elevate themselves above them. However, even though they may be subject to personal views and opinions, they are still a valid description of cannibalistic activities.

Recent research may yet put to rest the constant debate around cannibalism in archaeology. Hannah Koon (2003) of York University has conducted extensive research on the effects that cooking can have on bones, and how this can be visible in the archaeological record.

What began as research into heat induced morphological changes in bone collagen based on earlier research by Jane Richter (1986) has become one of the most high profile advancements in the cannibalism debate in recent years. Although the initial use of her work was in forensics, and not archaeological, it has been demonstrated to be particularly important in the debate surrounding cannibalism. In observing that the collagen structure of bones changes and deteriorates when heated, or more specifically boiled, it can be inferred within reasonable doubt that cannibalism must happen in at least some cases, as the cooking of human remains is extremely unlikely unless there is the intent of consumption.

Analysis using this new technique is currently being carried out on some of the human remains that have previously been recovered from Herxheim, a site in Germany with evidence of what has been interpreted as cannibalistic consumption (Boulestin et al. 2009), which I will cover in more detail in a later post. However, to my knowledge the results of this analysis is as of yet unpublished.

The Problem With Cannibalism

The main problem surrounding the interpretation of any cannibalistic consumption is that it is such a sensational subject, both within archaeology and outside it. There is the significant potential for any modern attitudes, semantics and social constructions we have created around the word cannibalism to affect any interpretations and research based around it. The current approach regarding and leading to conclusions of cannibalism can be quite restrictive and leading, with judgements based on associated archaeological interpretations as well as ethnohistoric accounts being used to both prove and disprove instances of cannibalism (White 1992). Following this approach can lead to the exclusion of many of the necessary indicative features of cannibalism, because under such an approach they become inconsistent with such instances.

Ideally, sites with suspected episodes of cannibalism should be approached on an individual basis, which would ensure an objective approach to something that can differ so dramatically across the archaeological record both in manifestation and survival of evidence.

Part two can be found here.

Bibliography

Arens, W. 1979. The Man-Eating Myth. Oxford: University Press

Bahn, P. 1990. Eating People Is Wrong. Nature 348.

Boulestin, B., Zeeb-Lanz, A., Jeunesse, C., Haack, F., Arbogast, R., Denaire, A. 2009. Mass Cannibalism in the Linear Pottery Culture at Herxheim. Antiquity 83

Cannibal Holocaust. 1980. Online image available at https://lh6.googleusercontent.com/-NoQMPjLASeI/TW3DHg2iR3I/AAAAAAAAKu0/WoY_CZF7vOw/s1600/cannibal_holocaust.jpg last accessed 12th March 2011

Cannibalism in brazil described by Hans Staden. 1557. Online image available at http://spaghettiforever.wordpress.com/2010/08/27/cannibalismwikipedia/ last accessed 12th March 2011

Hogg, G. 1958. Cannibalism and Human Sacrifice. London: Hale.

Koon, H., Nicholson, R., Collins, M. 2003. A practical approach to the identification of low temperature heated bone using TEM. Journal of Archaeological Science 30, 11

Richter, J. 1986. Experimental study of heat induced morphological changes in fish bone collagen. Journal of Archaeological Science 13, 5

White, T.D. 1992. Prehistoric Cannibalism at Mancos 5MTUMR-2346. Princeton: University Press

Whittell, G. 1998. Tell-tale protein exposes truth about cannibals. The Times 8th November 1998.

Villa, P., Bouville, C., Courtin, J., Helmer, D., Mahieu, E., Shipman, P., Belluomini, G., Branca, M. 1986. Cannibalism in the Neolithic. Science 233

The Basic Muscles In The Human Body

10 Mar

The muscles are the main contractile tissues of the body involved in movement.  They cause motion and produce force that the body uses to move and manipulate the body.  There are both conscious and subconscious movements of muscles in the body system of a human as a whole.  Each muscle also has its own blood supply, arteries and veins, alongside  its own nerve connections.  Depending on the class of muscles we are looking at, or taken as a whole, the human body consists of around 640+ skeletal muscles.  As we are just looking at the basics to help understand where they are in relation to the major skeletal elements, I will not go into an in-depth discussion here just yet.

There are three kinds of muscles we need to know.

A) Firstly there is the skeletal muscle, which is used for locomotion and skeletal movement.  These muscles are often anchored by Tendons.  A tendon is simply a fibrous connective tissues, from the muscles to the bone elements.  A Ligament is often found in the joints of the body, and are connective fibrous tissues from bone to bone.  The movement of skeletal muscle is often a conscious decision.  The major muscles of the bum, the gluteal muscles, are some of the largest in the human body and are classed as skeletal muscle because they help locomotion of the thighs during ambulation.

B) The second type of muscle is the Smooth Muscle.  The smooth muscles are often found within the organs and structures of organs.  These movements tend to be subconscious, and help in the normal regulation of the human body.  An example of smooth muscle movement is in the use of swallowing food down the esophagus when eating, which involves the peristalsis movement.

C) The third type of muscle is the Cardiac Muscle.  As these muscles are only found within the heart, inside the pericardium sac; therefore detailed knowledge of this muscle collection is not needed when studying osteology.  The cardiac muscles are similar to the skeletal muscles.  However, they are subconscious as the heart beats at a fast and steady rate.

Below is the basic diagrams of the main muscles used in the movement of the modern  human body…

Anterior Muscles of the Human Body

Posterior Muscles of the Modern Human Body

Although this post was originally wrote a fairly long time ago, I have now finished the anatomy module of my MSc course here at the University of Sheffield.  This module composed of dissecting a human cadaver to help understand the vital soft tissues (muscles, nerves, arteries and fat) that are vital in the movement of a human.  I cannot say how vital this experience was in understanding the isolated, and even fully laid out, human skeleton.  It is vital in my opinion that practitioners of human osteology are given the chance to see how the flesh articulates, combines and moves with the skeletal anatomy.  Indeed, understanding the neuronal impulse from the brain, that then flows along the nervous system to engage the muscles to move,  and the skeleton to sustain and support that movement, is really key to understand the different elements, or systems, that make up the human body.