Expand the Inner Radius
If you side-bend your torso to the right, your left side will get longer. That’s true regardless of movement quality. But, what is your right side doing?
With less healthy movement, the right side will become crimped and pinched because too much contraction is used. The angle of bending becomes too severe. Tissue is compressed.
With skilled movement, the right side remains as long as possible, and the left side gets even longer. The general statement is: don’t over-compress the inner curve of bend. Stay long.
This principle can be applied throughout the body. For example, if you twist to the right with your whole body (feet to head), there are many places that might become overly shortened. Try to resist that. Go for length. Imagine that the body gets longer as you twist – like a spring uncoiling.
This principle can also be applied to a single joint movement. As an example, consider elbow flexion, where the hand is brought closer to the chest. Muscles from both the upper arm and lower arm cross the elbow joint. A less healthy way to flex the elbow is to over-tighten the upper arm and lower arm flexion muscles. That would unnecessarily pinch the crease in your elbow while the outside of the elbow expands.
A better way to do the same elbow movement is to use the least amount of flexion force needed. The outside of the elbow still expands, but the crease in the elbow isn’t pinched. This “long” elbow flexion spares the joint from compression and restriction, and the elbow should function well into old age.
Now suppose that you are standing straight, and there is no intentional bending or twisting. Most people will find that compressions exist anyhow. Over the years, compressions have worked their way into the body. After years of habit, they feel normal. For example, knees might become bent and can’t be straightened. Alternately, knees could become hyper-extended. In either case, muscles on one side of the knee are tighter than on the opposite side. Those knees will work better by loosening the tight side.
Try a whole-body thought experiment. Imagine that a very soft painless hose is placed into your mouth and down into the throat. The hose divides at two levels. One branch passes down each arm, goes through the inside bend of the elbow, and extends to the fingertips. The second branch travels down the front of the spine, splits at the legs, enters each leg, passes the back bend of each knee, and extends into the toes. Do you have the picture? Now, don’t crimp the hose.
This visualization relays the same general principle.
When in doubt, go for length and keep joints open. This is done by visualizing that the inner curve stays long.