Arms and Forelimbs, Human, Polar bear & Seal

I just spent Saturday morning studying the Extensor muscles of the human forearm. It is truly fascinating to see how all the muscles that extend both the hand at the wrist and the fingers originate on the bony prominence of the humerus called the Lateral Epicondyle. In a similar way, all the flexors originate on the opposite, inner bump called the Medial Epicondyle. The rest is a matter of muscle, tendon and what I consider puppetry – a matter of pulling strings to make things move at joints..

Speaking of joints, it is worth being aware of the nature of the different joints throughout the body. Whether hinge, ball and socket or compound joint, they will determine the movement of the limb.

On my way out of the College I stopped to look at the specimens they have on display. One of my favorites is the Polar Bear forelimb. Massive, powerful and sadly riddled with arthritis, it resembles the human but on a much bigger and mightier scale. Years ago when I worked in the Ungava area of Quebec (Nunavik now) I always was concerned about not meeting a polar bear out on the land or along the coast knowing their power and having heard many stories of their capabilities in the kill.

Below my study of the arm is another study of the forelimb of a Grey Seal. Predator and Prey. And still the same bones as our arms and hands, and yet different for its own function.

I intend to return soon to finish both sheet. I’ll post them as soon as done.