Or, more to the point, “At What Joints Should There Be No Movement During a Specific Exercise?”
But that’s a crummy title…
When we exercise, we tend to focus solely on the movement at hand. Though the movement is important, it’s far from the whole picture. While we’re using some muscles to create motion at certain joints, we’re also using several other muscles to resist motion pretty much everywhere else. Or, at least, we should be.
Resisting motion gives us a solid base from which to create stable positions, generate maximal force, and remain injury-free while doing so.
Think about a bicep curl. Standing, single-arm, with a dumbbell (just so we’re all on the same page). Where is the motion? That’s easy: the elbow joint (with a little bit of pronation and supination of the hand).
But the arm is hanging from the shoulder, so there’s tension there to resist the motion of the arm falling out of its socket. The fingers are resisting motion so the weight doesn’t fall to the ground. The muscles of the core are resisting any motion in the spine. Even the muscles of the feet are constantly on watch just to maintain balance.
Most of the above example happens without even thinking about it, but that is not always the case. In the squat, for example, it’s important to consciously resist inward motion of the knees on the way up (more on this next week). In a push-up, it’s important for the health of the shoulders to resist letting them creep up by your ears. In pretty much every exercise I can think of, it’s important to resist movement of the lumbar spine by remaining braced and tight.
(Remember: we're talking about movement in the joints. The spine is technically going to move in relation to your lower body and even the ground, but no parts of the spine are going to move in relation to each other.)
Consciously bracing and preparing to resist movement will not only help keep you from moving under load through compromised positions (which could lead to injury or pain in the long run), it will protect against straining or pulling muscles that wouldn’t otherwise be ready for action (which is, obviously, pretty immediate).
Ever picked something up and tweaked your back? Chances are, the sudden resistance made the muscles of your back go “Holy crap!” and tighten up as a reflex. And now that they think there’s some instability around them, they remain tensed to avoid future mishaps. It then takes awhile to convince them to relax.
Sometimes resisting movement takes care of itself, sometimes it doesn’t. Either way, it’s important to think about. So next time you’re about to perform an exercise (or pick up a baby or put something away on a shelf or sit down in a chair or carry groceries up the stairs), take a second to think not only about what is moving, but what’s not moving. In the beginning, this will require a lot of thought and awareness. Eventually, though, it’ll be just become another unconscious habit.