Six basic determinants of gait (Saunders et al, 1953):
The body uses strategies to maintain the centre of gravity in a horizontal plane, to increase efficiency, to decrease energy expenditure the classic six determinants of gait.
1. Pelvic rotation – the pelvis rotates in the transverse plane 4 degrees forward on the swing limb and 4 degrees backward on the stance limb.
2. Pelvic tilt – the pelvis tilts down 5 degrees in relation to the horizontal plane on the side opposite to that of the weightbearing limb.
3. Knee flexion after heel strike in the stance phase – at heel strike the knee is fully extended and at foot flat the knee is flexed 15 degrees
4. Foot and ankle motion – at heel strike the foot is dorsiflexed and the centre of rotation of the ankle is elevated. At foot flat the foot plantarflexes and the centre of rotation on the ankle is lowered. At push off the heel lifts from the floor and the centre of rotation of the ankle raises again.
5. Knee motion – at heel strike, when the centre of rotation of the ankle is high, the knee joint begins to flex. During midstance when the ankle centre is low the knee joint flexes a second time. The net effect of this close relation between the motions of the foot, ankle, and knee is to smooth the pathway of the centre of gravity.
6. Lateral displacement of the pelvis – the centre of gravity must shift over the stance foot to provide balance, otherwise the person will fall over the unsupported limb.
Some recent evidence suggests wrong. See Podiatry Arena