Flexion means bending in the joint – for example, if you clench your fist, you flexed your fingers. Bending the knee is called knee flexion. Opposite...
Extension is a movement occurring in the joint – for example, straightening the leg from the flexed knee position is extension. Opposite would be flexion
Distal signifies the distance from reference point being compared. The foot is more distal from the knee, in reference to the trunk. Opposite would be proximal.
