Biomech
5-28-99

Peripheral Nerves
•	don't offer any strength
•	do have weaknesses
•	read in book, he's going to go fast
•	require a lot of oxygen 
•	has a very good blood supply—all along has a & v coming into it
•	outer covering of the nerve has more stretch than the axon
•	if channel is intake, have a very good chance of regeneration
•	1mm/day regeneration 
•	crush and cut injury—regenerates but know where it will go b/c outer covering has been damaged
•	stretch a nerve and block venous return, which in turn blocks arterial supply—ischemia
•	upper extremity should remain the same throughout life
•	lower extremity will diminish as we age

Muscle
•	function is to move bone
•	table 5-2, Biomechanics of Skeletal Muscle
•	work—positive or negative
•	concentric contraction—muscle tension equals external load.  Muscle shortens
•	eccentric contraction—lengths
•	isokinetic—maximal muscle movement
•	isotonic—holds everything in place
•	isoinerial

Makeup
•	table 5-3 p104
•	Type I—repetitive movement, red, slow, fiber diameter is slow
•	Type IIA—fast, intermediate, red
•	Type IIB—lots of power, real fast, right now
•	innervation determines what type the muscle will be
•	a training program can change the types but not very much
•	soleus—posture
•	gastroc—movement
•	when train for one sport, increase on type of muscle and decrease the other
•	this makes the person weaker for some types of movements
•	makes more prone to injury

Drugs and Muscles
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