Knee

Click pic to enlarge	Muscle(s)	Movement
Knee Flexion	Hamstrings Gracilis Sartorius Popliteus Gastrocnemius	Decreasing angle between adjoining bones – e.g. between the femur and the tibia/fibula.
Knee Extension	Quadriceps	Increasing angle between adjoining bones – e.g. between the femur and the tibia/fibula.

Click pic to enlarge

Muscle(s)

Movement

Knee Flexion

Hamstrings
Gracilis
Sartorius
Popliteus
Gastrocnemius

Decreasing angle between adjoining bones – e.g. between the femur and the tibia/fibula.

Quadriceps

Increasing angle between adjoining bones – e.g. between the femur and the tibia/fibula.