Which of the following pairs are types of joint actions?

Flexion and extension are fundamental types of joint actions that occur at various joints in the body. Flexion refers to a movement that decreases the angle between two body segments, effectively bringing them closer together, such as bending the elbow or knee. Extension is the opposite movement, increasing the angle between the segments, like straightening the arm or leg.

This pair of actions is essential for understanding human movement, particularly in exercise and rehabilitation contexts, as they are frequently involved in everyday activities and various physical exercises. Mastery of these movements is crucial for anyone working in fitness or physical therapy, as they form the basis for more complex movements and can help in assessing a client's range of motion and functional abilities.

While the other pairs mention a variety of movements, they do not encapsulate the specific nature of joint actions as clearly as flexion and extension. For instance, contraction and relaxation denote muscle actions rather than joint movements. Stretching and compressing might imply some joint involvement but do not define standard joint actions. Turning and tilting refer to movements that can involve joints but again lack the precision that flexion and extension have in defining typical joint action ranges.