joint movements

When you tell someone 'bend your arm', it is clear enough at the dinner table — but a clinical note that says 'the arm moved a bit' is useless. Medicine therefore gives each direction of joint movement a precise name, so that any clinician, anywhere, reading the chart pictures exactly the same motion. These terms are the shared grammar of the body's movement.

The core pairs come from the planes. Flexion and extension are the forward-and-back movements: flexion usually bends a joint and decreases its angle (bending the elbow), extension straightens it (straightening the elbow). Abduction and adduction are sideways movements: abduction moves a limb away from the body's midline (lifting the arm out to the side), adduction brings it back toward the midline. Rotation turns a part around its long axis — internal (medial) rotation turning it inward, external (lateral) rotation turning it outward. Some joints have special names: at the forearm, pronation turns the palm down and supination turns it up; at the ankle, dorsiflexion lifts the foot up and plantarflexion points it down. The point of the vocabulary is precision — 'flexion' is unambiguous in a way that 'bent' is not.

These words are the working units of nearly every rehabilitation goal and measurement. A note that a shoulder has '90 degrees of flexion' or that an ankle 'lacks dorsiflexion' tells the whole team precisely what is limited and what to work on. The honest caveat is that the named movements are clean single-plane ideas, while a real task — putting on a seatbelt, climbing stairs — blends several of them; so restoring each isolated movement does not by itself guarantee the smooth, combined motion daily life needs.