Can One Muscle Really Turn Off Another? A Look at Reciprocal Inhibition
Photo By Pearson Scott Foresman [Public domain], via Wikimedia Commons
To answer this question, we need to define the term reciprocal inhibition:
Reciprocal inhibition: Muscles on one side of a joint relax, in order to accommodate a contraction on the other side of the joint.
For example, the triceps muscles (on the back of the upper arm), relax to allow movement of a dumbbell during a biceps curl (contraction of muscles on the front of the upper arm). Now, this is great when you’re in the weight room doing 3 sets of 15 for each of the major muscle groups. We don’t want our biceps and triceps fighting each other. We generally want to avoid battle between our quads and hamstrings. But what if we’re talking about a sustained contraction, one that you might maintain for, oh let’s just say 8 hours, during a typical work day?!
One of the main muscles that’s chronically contracted when we sit in chairs is the psoas. This is a deep muscle that attaches at the top of your thigh, and allows you to lift your leg out in front of you. In a sitting posture, the muscle is constantly contracting, and through this same mechanism of reciprocal inhibition, the muscle on the other side of the joint is going to relax. What’s on the other side of the joint from the psoas? The GLUTE MAX! The gluteal muscles get “shut off” thanks to tight hip flexors, a condition known as DEAD BUTT SYNDROME. The glutes don’t fire as quickly and as strongly as they should, and this results in symptoms like hip, butt, and leg pain. This condition is not good, but it can be treated through a combination of releasing the tightness in the psoas and strengthening the glutes.
A bigger problem develops if this is left untreated, since now the largest muscle on the back of the body is not working! We are amazing at compensating, so now some smaller muscles in the area try to take over the work. As you can imagine, things don’t go quite as smoothly. Read more about how this problem results in piriformis syndrome and sciatica.
To find out whether you have Dead Butt Syndrome, piriformis syndrome, or sciatica, call your Oakland sports chiropractor at (510) 465-2342.