Antagonistic muscle action

3.1.1.1 The structure and functions of the musculoskeletal system

What you need to know

Describe the major muscle groups operating at the shoulder, elbow, hip, knee, and ankle joints.
Identify the bones located at these major joints.
Explain the action of prime movers (agonists) and antagonists in movement.
Understand how muscle groups work isometrically and isotonically.
Differentiate between concentric and eccentric (isotonic) muscle contractions.