The function of the human hand is unlike that of any other
animal and its’ anatomy is fascinating and complex. However, in fitness, the hand is often taken
for granted. Understanding hand anatomy and alignment will help you to improve
your full body alignment and stability in core conditioning exercises like
plank, push ups, and any arm balance poses.
The skeletal structure of the hand & wrist is very
similar to the skeletal structure of the feet.
(see previous post: START WITH A STRONG FOUNDATION). There are 27 bones in each hand, which means our hands
contain ¼ of the bones in our body. The
bones can be divided into 3 groups: carpals (8 bones), metacarpals (5 bones),
and the phalanges (14 bones).
The muscles of the hand are divided into the intrinsic &
extrinsic muscle groups.
Intrinsic muscles are located within the hand itself. Extrinsic muscles are located in the forearm
and attach to the hand through a network of tendons. The majority of muscles that flex and extend
the wrist, and many of the muscles that move the fingers are extrinsic muscles.
The hands are innervated by three nerves: the median nerve (innervates the muscles that help with fine motor or "pinch" function), the ulnar nerve (innervates the muscles that help with a strong hand grasp or grip), and the radial nerve (innervates the wrist extensors helping to control positioning and stability of the hand).
The nerves that innervate the hand all originate in the
brachial plexus. The brachial plexus is
a network of nerves that begin at the spinal cord in the neck (cervical
spine). These nerves control movement
and sensation in the hand, wrist, elbow and shoulder by carrying messages from
the brain to the muscles and other connective tissues. The nerves extend from
the brachial plexus and continue down the through the forearm and ultimately
enter the hand through small canals in the wrist. The most well known of these canals is the
carpal tunnel. The median nerve travels
through the carpal tunnel to enter the hand.
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| credit: http://cochiro.com |
Just as in the feet, the hand bones form arches that are
essential to complex manipulation of objects.
These arches also function as support structures whenever we are bearing
weight in our hands. By maintaining the
arches of the hands through proper alignment and use of all of the intrinsic
and extrinsic hand muscles, you can keep the nerves free from pressure and
injury and create a strong foundation that will translate into better alignment
through the entire kinetic chain.
Here is a really great, simple video demonstration of proper
hand foundation. Click on the video "hands foundation".
Next time you practice any exercise that requires bearing
weight in your hands, take the extra time to focus on your hand
foundation. You’ll find you can hold
plank poses and arm balances longer, increase your push up count, and
ultimately improve not only your upper body strength but your core strength as
well!
