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A Right To Bear Arms: A Traumatically Introduced Ursus Phalanx

31 May

Whilst browsing a recent edition of the International Journal of Palaeopathology I came across this article by Richards et al. (2013) titled ‘Bear Phalanx Traumatically Introduced Into A Living Human: Prehistoric Evidence‘; it is an eye-catching title I am sure you will agree!  Although it is common for skeletal remains to display traumatically introduced pathologies (see Roberts & Manchester 2010 and Waldron 2009), it is rare for palaeopathological case studies to document traumatically inserted foreign objects into a human skeleton, much less so to find a bear claw crushed into a human arm.  Yet this is exactly the case that Richards et al. (2013) document in a female skeleton dating from a Middle Period (500BC-300AD) Prehistoric Californian shellmound site called Ellis Island.

The individual, PHMA 12-2387, was found during archaeological excavations conducted in1906-1907 of the shellmounds that formerly lined the San Francisco Bay area, and the excavation recovered a total of 160 burials from the highly stratified shellmound middens (Richards et al. 2013: 48).  The shellmounds along the San Francisco Bay were inhabited by hunter-gatherers during the Middle Period, who focused their efforts on the near shore marine rich resources.  Interestingly the habitation period of the area at and around Ellis Island reflects occupation, abandonment and re-occupation over a 2000 year long span.  Following the osteological analysis of the nearly complete skeletal remains of PHMA 12-2387, it was concluded that the skeleton likely represented an adult female (biological sex based on pelvic features) aged between 30-40 years old (based on dental eruption and wear stage, epiphyseal and sutural closure, pubic symphysis and joint  surface morphology) at the time of death, who was buried supine with both her upper and lower limbs flexed (Richards et al. 2013: 49).

Now here is the interesting part.  Following the qualitative analysis of the normal ranges of joint and bone surface morphology of other shellmound individuals (N=159) and the comparison of the careful analysis of CT scans taken of the arms of PHMA 12-2387, it was concluded that the upper limbs bones of PHMA 12-2387 were large and strongly muscled, which were representative of a middle aged female who had suffered ‘traumatic injury that involved the left cubital fossa region, both forearms, and the right shoulder girdle’ (Richards et al. 2013: 50).  The right upper limb displays a bending fracture in the mid shaft of the ulna, which was complicated by the non-union of the break during the healing process.  Found within the left humerus cubital fossa was a Ursus (bear) phalanx, which had been driven in by a likely crushing trauma to a depth of 5 to 7mm into the dense cortex of the humeral shaft (See Figure 1).

Beartraumarichardsetal20133333

The CT scans of the upper limbs of PHMA 12-2387, where A represents varying views of both remaining limbs, and B shows the traumatically fractured right ulna and crushing injury of left cubital fossa of the humerus (See Richards et al. 2013: 50 for further information).

The injuries to this individual undoubtedly affected her movement.  The right upper limb would have suffered from problems with restricted range of the elbow joint, and restricted pronation and supination of the forearm due to the non-union fracture, whilst the trauma of the phalanx fractured through olecranon process and likely severed the m. triceps brachii, a major forearm extensor.  This likely resulted ‘in unopposed forearm flexion’, although pronation and supination of the forearm was ‘less affected’, with the bone material adapting to, and reflecting, the changes (Richards et al. 2013: 51).  The Ursus phalanx became fused within the injury of PHMA 12-2387′s left arm, and remained there until her death.

Although hypothetical situations are documented by Richards et al. in a  trauma reconstruction, it is likely thought that the upper limb injuries occurred at the same time as each other, and that the Ursus phalanx represented a part of a decoration (possibly a necklace) worn by the individual in question.  The mechanism of the introduction of the phalanx is likely to have been a devastating crushing injury which rammed the phalanx into the bone, as documented by the surrounding tissue damage.  Richards et al. 2013 (52-53) suggest that the individual was wearing a possible necklace of ‘claws’, with the phalanx having a shamanic connotation or reflecting a high status within the Middle Period horizon cultures.  Ethnographic accounts of Central Californian tribes indicate that shamans were ‘an integral part of the political, economic and legal institutions’ (Richards et al. 2013: 52).  A number of scenarios regarding her possible role within a society are postulated, and although no firm conclusion can be made, the case calls for a unique perspective for a personal osteobiography during the Californian prehistoric period.

Importantly this case study of this unfortunate individual highlights the coming together of the historical, the ethnographic, the osteological and the anatomical.  Whilst the hypothetical situation of the cause of the trauma can be discussed and postulated, it nevertheless stimulates a worthwhile discussion on the role of shamanistic behaviour in prehistoric California and it adds to the importance of understanding the injuries on the living individual, a living osteobiography.  It is an important article and well worth the full read.

Bibliography:

Richards, G., Ojeda, H., Jabbour, R., Ibarra, C., & Horton, C. (2013). Bear phalanx traumatically introduced into a living human: Prehistoric evidence International Journal of Paleopathology, 3 (1), 48-53 DOI: 10.1016/j.ijpp.2013.01.001

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

Waldron, T. 2009. Palaeopathology. Cambridge: Cambridge University Press.

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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

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 Arm Bones And Major Landmarks, As Seen In Articulation With The Full Limb.

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

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 In Articulation

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 Landmarks of Humerus (Click to enlarge.)

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, click to enlarge.

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).

Colles’ Fracture

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.

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