Complex sentence: The force of the contraction, which is associated with the exhale, can initiate movement of the body through space; the release may be considered a relatively passive return to a "normal" state, or alternatively as an equally active outward propulsion of energy.
Split into simpler sentences: The force of the contraction, which is associated with the exhale, can initiate movement of the body through space. The release, associated with the exhale may be considered a relatively passive return to a "normal" state, or alternatively as an equally active outward propulsion of energy.