vol 2
1. The Hip
2. The Knee
3. The Ankle
4. The Foot
1. The Hip
2. The Knee
p 78 , one degree freedom of – flexion-extension
ให้ extremity of limb move toward /away from – root
controllng distance ระหว่าง body/ground
esesential – axial compression – under action of gravity
knee ยังมี accessory or 2nd degree of freedome – rotation of axis of leg ตอน knee flexed
3. The Ankle
4. The Foot