hip extension muscle posterior muscles - gluteus maximus muscle (the largest muscle in the body) and the hamstrings group, which consists of the biceps femoris, semimembranosus, and semitendinosus muscles. The sartorius muscle is innervated by the femoral nerve. The sartorius muscle can move the hip joint and the knee joint, but all of its actions are weak, making it a synergist muscle.

This is the most movable end of the body of the muscle (wiseGEEK).

Origin/insertion. The muscle corkscrew obliquely through the thigh from lateral to medial side to reach the posterior aspect of the medial condyle of femur, where its tendon runs forwards to be added into the upper part of the medial outermost layer of the shaft of tibia in front of the insertions of gracilis and semitendinosus.The insertion of sartorius is inverted hockey stick-shaped. Origin: Area between the ASIS (Anterior Superior Iliac Spine) and AIIS (Anterior Inferior Iliac Spine).

Attachments of the Sartorius Origin-originates from the anterior superior iliac spine Insertion-attaches to the superior, medial surface of the tibia.

Insertion: Anterior part of the medial condyle of the tibia. The muscle may be absent in some people. The tendon of insertion may end in the fascia lata, the capsule of the knee-joint, or the fascia of the leg. Sartorius: The sartorius muscle is the longest muscle in the body.

Function of the Sartorius It acts on flexion, abduction and lateral […] The Sartorius is a two-joint muscle and so is weak when the knee is flexed and the hip is flexed at the same time. Function. This nerve arises from your low back at lumbar level two, three, and four. The sartorius muscle receives blood supply from various arteries the penetrate the muscle at irregular intervals. Long and thin, the sartorius muscle spans the distance of the thigh.
Origin : Anterior Inferior Iliac Spine (AIIS). It is a powerful knee extensor when the hip is extended (back), but is weak when the hip is flexed (forwards). The origin of the sartorius muscles is located at the anterior superior iliac spine of the pelvic bone. The sartorius muscle inserts on the medial side of the knee and proximal region of the tibia.

When the muscle contracts, the insertion is pulled towards the origin, producing movement at the joint between the two bones.

The anterior muscles - such as the quadriceps femoris, iliopsoas, and sartorius, work as a group to flex the thigh at the hip and extend the leg at the knee.

It is the only of the quadriceps group knee muscles which also crosses the hip joint.
At the hip, it can flex, weakly abduct, and laterally rotate the thigh.

Insertion: Top of the patella and the patella tendon to the tibial tuberosity. It works better during single movements.

The sartorius muscle is positioned more superficially than the other in the leg muscles.