It can be challenging to lift the arms in this relationship to gravity, with the spine in extension. If the latissiums dorsi are used to extend the spine (rather than the deeper, intrinsic spinal muscles), they will inhibit the movement in the arms.

This position of the legs uses a complex interaction among adductors, medial rotators, and hip extensors. This is because many of the muscle actions that lift and support the body in this position create other actions that must be neutralized by opposing or synergistic muscles. For example, because the gluteus maximus, a powerful hip extensor, also rotates the legs, it’s preferable to use the hamstrings for hip extension. Additionally, the gluteus medius and minimus, which help with internal rotation, also happen to abduct the leg, so the adductors will kick in to keep the legs together. Therefore,m there are always lots of synergistic actions going on. People will have different priorities, or challenges, depending on where they start and their preexisting patterns of strength/weakness and flexibility/tightness.