• Function: Abduction, medial rotation and flexion of the thigh; Protects the knee joint.
• Innervation: Superior gluteal nerve (L4-L5)

• Function: powerful extensor of hip joint, lateral rotator; Active in rising, sitting, and climbing.
• Innervation: Inferior gluteal Nerve (L5-S2)

• Function: Abduction, medial rotation of thigh; It keeps pelvis level when opposite leg is raised.
• Innervation: Superior gluteal nerve (L5-S1)

• Function: Abduction, medial rotation of thigh; It keeps pelvis level when opposite leg is raised.
• Innervation: Superior gluteal nerve (L5-S1)

• Function: Lateral rotator and abductor of the thigh; Keeps femur head in acetabulum.
• Innervation: Nerve to piriformis (sacral plexus) (S1-S2)

• Function: Lateral rotator of the thigh when it is extended and abductor of the thigh when flexed; Lateral rotators are stronger than medial rotators and control balance.
• Innervation: Nerve to obturator internus (L5-S1)

• Function: Lateral rotator of the thigh when it is extended and abductor of the thigh when flexed; Lateral rotators are stronger than medial rotators and control balance.
• Innervation: Nerve to obturator internus.

• Function: Lateral rotator of the thigh when it is extended and abductor of the thigh when flexed; Lateral rotators are stronger than medial rotators and control balance.
• Innervation: Nerve to quadratus femoris.

• Function: Lateral rotator of the thigh when it is extended and abductor of the thigh when flexed; Lateral rotators are stronger than medial rotators and control balance.
• Innervation: Nerve to quadratus femoris

Posterior Thigh Muscles

(Hamstring Muscles)

• Originate from the Ischial Tuberosity
• Innervated by the Tibial branch of the Sciatic Nerve
• Flexors (strong) of the knee joint
• Extensors (weak) of the hip joint
• Insert around the bones of the knee joint

Biceps femoris -

Long Head

• Function: Extension at the hip. It is a flexor and lateral rotator at the knee joint.
• Innervation: Tibial Nerve (L5-S2)

Biceps fermoris -

Short Head

• Function: Knee flexor.
• Innervation: Common Peroneal Nerve (S1-S2)
• Short Head may be absent!

• Function: Extension at the hip, flexion and medial rotation at the knee.
• Innervation: Tibial Nerve (L5-S2)

• Function: Hip extensor, knee flexor, and medial rotator.
• Innervation: Tibial Nerve.

• Function: Powerful adductor, lateral rotator (part that is inserted to the linea aspera), medial rotator at the knee joint. Extensor at the hip.
• Innervation: Tibial Nerve to the part inserted to linea aspera. Obturator Nerve to the part inserted to adductor tubercle (puberty and conception).

• Soleus
• Gastrocnemius
• Plantaris

• Function: Active in hard motion and sustaining motion (Red fibers).
• Innervation: Tibial Nerve (S1-S2).

• Function: Active for fast movements (White fibers).
• Innervation: Tibial Nerve (S1-S2).

• Function: Best plantor flexor. Active in walking.
• Innervation: Tibial Nerve (S1-S2).

• Calcaneal tendon.
• Most powerful tendon and important for walking.

• Function: Plantar flexion and Supination of the foot.
• Innervation: Tibial Nerve (L4-L5).
• Tendon passes beneath the Flexor retinaculum!

• Function: Plantar flexion and Supination of the foot.
• Innervation: Tibial Nerve (S1-S2).
• Tendon passes beneath the Flexor retinaculum!

• Function: Plantar flexion and Supination of the foot.
• Innervation: Tibial Nerve (S1-S3).
• Tendon passes beneath the Flexor retinaculum!

• Function: Flexion of the knee, unlocking of the knee joint, and protection of the lateral meniscus.
• Innervation: Tibial Nerve (L4-S1)

• Function: One of the two strongest pronators of the foot. Eversion at the subtalar and talocalcaneonavicular joints (Standing on the medial margin of the foot while the lateral margin is up).
• Innervation: Superficial Peroneal Nerve (L5-S1).
• Tendon runs behond the lateral malleolus!

• Function: One of the two strongest pronators of the foot. Eversion at the subtalar and talocalcaneonavicular joints (Standing on the medial margin of the foot while the lateral margin is up).
• Innervation: Superficial Peroneal Nerve (L5-S1).

• Function: Adductor of the thigh, flexor at the hip and flexor at the kee joints.
• Innervation: Obturator Nerve.

• Function: Adductor of the thigh and flexor of the hip joint.
• Innervation: Femoral Nerve (L2-L3) & Obturator Nerve.

• Function: Adductor of the thigh & flexor of the hip joint.
• Innervation: Obturator Nerve (L2-L4)

• Function: Adduction of the thigh and hip flexion.
• Innervation: Obturator Nerve
• Lies on the adductor magnus.

• Function: Powerful adductor, lateral rotator (part inserted to linea aspera), medial rotator at the knee joint. Extensor at the hip.
• Innervation: Tbial Nerve to the part inserted to the linea aspera. Obturator Nerve to the part inserted to adductor tubercle (puberty and conception).

• Function: Powerful adductor, lateral rotator (part inserted to linea aspera), medial rotator at the knee joint. Extensor at the hip.
• Innervation: Tbial Nerve to the part inserted to the linea aspera. Obturator Nerve to the part inserted to adductor tubercle (puberty and conception).

• Function: Cheif flexor of the hip.
• Innervation: Lumbar plexus to psoas (L1-L3) and Femoral Nerve to iliacus (L2-L4).
• Composed of two muscles: Psoas major and Iliacus muscles.

• Function: Chief extensor of the knee joint. Rectus femoris also flexes at the hip joint.
• Innervation: Femoral Nerve (L2=L4).
• Consists of four muscles: Rectus femoris, Vastus lateralis, Vastus intermedius, and Vastus Medialis.

• Function: Acts on two joints: flexes at both the hip joint and the knee joint.
• Innervation: Femoral Nerve (L2-L4).

• Function: Dorsiflexion and supination of the foot.
• Innervation: Deep Peroneal Nerve. (L4-L5).
• Tendon passes beneath the extensor RT.

Extensor digitorum longus

• Function: Dorsiflexion of the foot.
• Innervation: Deep Peroneal Nerve (L5-S1).

• Extensor digitorum's addtional part that may extend to the base of the 5th metatarsal.
• May even be a muscle and have a seperate origin.
• Innervation: Deep Peroneal Nerve.

• Function: First toe dorsiflexion.
• Innervation: Deep Peroneal Nerve (L4-S1).

• Function: Dorsiflexion of the digits.
• Innervation: Deep Peroneal Nerve (S1-S2).

• Function: Dorsiflexion of the first digit.
• Innervation: Deep Peroneal Nerve (S1-S2).

• Longitudinal and transverse fibers. It maintains the longitudinal arch of the foot and protects the vessels and nerves.

• Function: Abduction of the 1st digit.
• Innervation: Medial Plantar Nerve (L5-S1).

• Function: Flexion of the 1st digit.
• Innervation: Medial Plantar Nerve (L5-S1).

• Function: Flexion of the digits.
• Innervation: Medial Plantar Nerve (L5-S1).

• Function: Plantar flexion of digits.
• Innervation: Medial Plantar Nerve to 1st Lumbrical. Lateral Plantar Nerve (S2-S3) to the 2nd, 3rd, and 4th Lumbricals.

• Function: Assists Flexor digitorum longus in flexion
• Innervation: Lateral Plantar Nerve (S1-S2).

• Function: Adductors of the digits.
• Innervation: Lateral Plantar Nerve (S2-S3)

• Function: Abductors of the digits.
• Innervation: Lateral Plantar Nerve (S2-S3).

• Innervation: Lateral Plantar Nerve (S1-S2)

• Innervation: Lateral Plantar Nerve (S1-S2)

• Innervation: Lateral Plantar Nerve (S1-S2)

• Innervation: Lateral Plantar Nerve (S1-S2)