Muscles involved in movement are classified functionally as agonists (primary movers), synergists (assistants or stabilizers), and antagonists (oppose the movement). Agonists generate torque against resistance and include prime movers that are most mechanically involved in an exercise, while synergists enhance efficiency or stability without being the main drivers. However, muscle roles are context-dependent, influenced by individual mechanics, technique, and even intent—highlighting the complexity of assigning strict roles in functional analysis.
This article introduces the foundational concepts of anatomical directions, planes, and motions, which are essential for analyzing and communicating human movement. Understanding these terms helps practitioners describe joint positions, segment motion, and exercise mechanics with clarity. Whether you are coaching calisthenics or studying biomechanics, this knowledge forms the basis of effective movement analysis.
