Co-contraction of the agonist muscles (the prime movers, who mostly get the credit) and the antagonist muscles (the opposing muscles that create stability and support in the joint) occurs to ensure smooth and controlled movement.

The goal of yoga is to build health. First stabilize a joint, then work to mobilize it. This is especially important for the core joints of the spine, pelvis, shoulders and knees. All joints will benefit from co-contraction of surrounding muscles.