The great extensor muscle of the knee, divided above into four parts which unite in a single tendon at the knee.
The muscles of the front of the thigh (upper leg), their main function is to straighten (extend) the knee.
A muscle group at the front of the thigh connected to a common tendon that surrounds the knee cap and attaches to the tibia (lower leg bone). The individual muscles are the rectus femoris, vastus intermedius, vastus lateralis and vastus medialis. Acts to extend the lower leg.