So You Lose a Little Muscle—So What?

Any of my former students who read the Memo should remember the following definition quite well:

A motor unit is a nerve and all the muscle fibers to which it attaches.

It’s called a unit because both sides of that equation are important. Muscle fibers contract when stimulated by a nerve. Reduce the number of fibers that the nerve can attach to, and the muscle won’t generate as much force. Losing a little strength is no big deal, right? How about walking up a flight of stairs? Or even being able to maintain balance while standing? Yes—it’s a big deal.

Sarcopenia is the progressive loss of muscle strength and function as people age. How much loss? Just look at the picture from the Journal of Physiology: the loss of muscle is obvious and with that, a loss of function. Let that sink in. I’ll talk about whether anything can be done about it the rest of the week.

What are you prepared to do today?

Dr. Chet

 

Reference: J Physiol. 2018 Mar 11. doi: 10.1113/JP275520.