Consider The Arm: Explain The Difference Between The Biceps And The Triceps

Consider the arm. The biceps and the triceps are on two sides of the upper arm bone (humerus) and attach to the fore arm bones (radius and ulna) from the inside and outside of the elbow joint. Contraction of the bicep causes your arm to fold. Contraction of the triceps causes your arm to extend
, your biceps muscle is attached to your shoulder blade at one end and to your ulna in your forearm at the other end. When the biceps contracts, it shortens and pulls the ulna toward the shoulder blade (the ulna is attached to the elbow joint). This movement allows you to lift your forearm and a given load.
Full Answer

Different muscle groups are responsible for the action of the major joints in the leg. For example the muscles of the buttocks, hips