Leg raises are one type of exercise that works the hip flexor muscles. These muscles include the iliopsoas, rectus femoris, sartorius, and pectineus. Exercises for hip extension include squats or leg presses. Hip extensor muscles are the hamstrings and the gluteus maximus. Hip abduction exercises can be done with an exercise machine. Muscles involved with hip abduction include the tensor fascia latae, sartorius, and gluteus minimus and medius. Leg curl exercises involve knee flexion. Muscles involved with flexion of the knee are the hamstrings, gracilis, and popliteus.