This week several people on our TriggerPoint Yoga Facebook page were talking about muscle memory and why repetitive movements will cause the muscles to shorten and cause joint pain and stiffness. I decided that this would be the topic for today’s blog post.
Muscle memory, according to Wikipedia, is only discussed in terms of how it works with the body to do repetitive movements such as playing the piano so your fingers move easily across the keys, or typing without thinking about where the letters are located simply because you’ve trained your fingers to find the right combination of letters. But that’s only half of the explanation for the term “muscle memory,” the other half is how it relates to repetitive strain injuries.
I doubt that anyone is interested in hearing the really technical reason so we’ll leave that for people to investigate further if this is of interest to them. The short answer is, when a muscle fiber is repeatedly contracted and released over and over it creates a toxic by-product that then causes the fiber to tie into a spasm that feels just like a knot in the muscle. Another repetitive strain on the muscles happens when you shorten a muscle and then stay that way for an extended period of time, such as when you drive a long distance and your hand is gripping the wheel for hours. It will be easy to describe this if we look at how the muscles can shorten and cause the exact same symptoms as carpal tunnel syndrome.
While muscles from your neck to your hand can cause the tingling and numbness you feel in your thumb and first two fingers, let’s concentrate on the muscle of your forearm that will cause the wrist pain associated with carpal tunnel syndrome. There are two groups of muscles we’ll focus on here: your flexor muscles are on the underside of your forearm and your extensor muscles are on the top side of your forearm. When your contract your flexor muscles you will curl your hand into a fist and down toward the inside of your wrist, and when you contract your extensor muscles your hand will totally open and then move up back (like when you do a push-up).
If you use a computer for hours, whether it’s for work or fun, or if you play tennis, the piano, or any of a million activities that make your fingers &/or wrist curl and open, you are using your flexors and extensors. This is a classic repetitive strain injury and it’s very common. Another classic repetitive strain injury happens when you shorten a muscle and then stay that way for hours, in fact, sitting is the #1 reason for low back pain, but that’s such a long story that we won’t go into it here. If you have low back pain you can read about here.
The muscle fibers had to contract to pull you into the shortened length, for example, gripping the steering wheel. As they stay that way, muscle memory sets in and the fibers actually change their length to the now shorter length. The problem comes in when you try to move in the opposite direction, for example opening your hand and pulling it back to push your car door shut. The fibers are too short to make that movement and since the flexor tendons pass through your carpal tunnel (at your wrist) along with your median nerve, the tight tendons entrap the nerve within the tunnel and your fingers tingle &/or go numb.
Everyone pays attention to your numb fingers, but most of the time the tight muscles are ignored. I’ve found that simply releasing the tight muscles, reversing the muscle memory of the muscles, will take the pressure off the median nerve and your fingers come back to normal again.
So, while muscle memory will cause joint pain (in this case, the wrist) anywhere in your body, it’s easy enough to reverse the pain by simply properly treating the muscle fibers to return them to their proper length. This is true whether it’s shorten muscles causing headaches or low back pain, or a shortened muscle putting pressure on your sciatic nerve.
Having said all of this, I’ve seen over and over how some simple self-treatments will reverse muscle memory, so it doesn’t ever need to become an issue.
Wishing you well,