The main muscles of the hip and pelvis consistsof the iliopsoas, pectinues, rectus femoris* and sartorius at the front. The gluteus medius, gluteus minimus, piriformis, tensor fasciae latae on the outside. Gluteus maximus, biceps femoris*, semitendinosus*, semimembranosus* at the back and the adductor or groin muscles (adductor brevis, adductor longus, adductor magnus and gracilis*). * means these muscle cross the knee joint as well.
Adductor Longus is the middle of the three short adductor muscles (adductor brevis and pectineus are the other two). The adductor magnus and gracilis are the two long adductor muscles which go from the pubic bone to the knee.
The Rectus Femoris muscle is part of the Quadriceps muscle group. It is the only muscle of the group which crosses the hip joint and is a powerful knee extensor when the hip is extended, but is weak when the hip is flexed.
he Piriformis muscle is an important muscle. The sciatic nerve passes underneath this muscle on its route down to the posterior thigh. In some individuals the nerve can actually pass right through the muscle.This can lead to sciatica symptoms due to a condition known as piriformis syndrome.
Gluteus Medius is an important muscle in controlling the level of the hips. Weaknesses in gluteus medius often result in a trendelenburg sign, an abnormal gait cycle where the hip of the swinging leg drops down, rather than raises up. This results in increased degrees of knee flexion in order to clear the ground.