What type of movement occurs at a) the hip and b) the knee during the downward phase of a squat?

First, think about the plane of movement that the action is occuring in. During a squat, the body looks the same when you cut it vertically down the middle. The movement is therefore occuring in the sagittal plane. The two movements that occur in this plane are flexion and extension therefore it must be one of these two. a) FlexionThe angle at the hip is getting smaller as you bend your trunk forwards towards your legs therefore it is flexion rather than extension. b) FlexionAgain this is due to a decrease in the angle between the bones at the joint.