Biceps Femoris

General information

The Biceps femoris is a long muscle in the thigh, located in the posterior region. It is part of the hamstrings, along with the semitendinosus and semimembranosus muscles.

Literal meaning

Two headed muscles on the femur.

Interesting information

This muscle is located over two joints and therefore has actions over both the hip joint and the knee joint.

This muscle has two heads with different origins and innervations but the same insertion.

Origin

Long head: ischial tuberosity, sacrotuberous ligament.

Short head: linea aspera of femur, lateral supracondylar line of femur.

Insertion

(Lateral aspect of) head of fibula.

Function 

Hip joint: thigh extension, thigh external rotation.

Knee joint: leg flexion, leg external rotation; stabilises pelvis.

Nerve supply

Long head: tibial division of sciatic nerve (L5-S2).

Short head: common fibular division of sciatic nerve (L5-S2).

Blood supply

Inferior gluteal artery, perforating arteries, popliteal artery.

Relevant research

Kellis (2018) found that “to achieve greater lengthening of the fascicles of the Biceps Femoris long head, passive stretch with the hip flexed at least 45° and the knee reaching full extension is necessary.”

Alonso-Fernandez et al (2018) found that Nordic Hamstring Exercise “may cause alterations in the architectural conditions of the Biceps Femoris long head and may have practical implications for injury prevention and rehabilitation programs.”

Kellis E. (2018). Biceps femoris fascicle length during passive stretching. Journal of electromyography and kinesiology: official journal of the International Society of Electrophysiological Kinesiology, 38, 119–125.

Alonso-Fernandez, D., Docampo-Blanco, P., & Martinez-Fernandez, J. (2018). Changes in muscle architecture of biceps femoris induced by eccentric strength training with nordic hamstring exercise. Scandinavian journal of medicine & science in sports, 28(1), 88–94.

Biceps femoris exercises

Strengthening:

Nordic hamstring curl

Kneeling with a pillow or mat in front of you. Ask someone to hold your ankles and when you are ready lower your upper body downwards in a controlled way. Get ready with your arms, with your arms out in front of you, to stop yourself as you get closer to the floor. Upon touching the floor, return to the starting position and repeat.

Stretch:

Hamstring stretch

Standing, put your foot on a chair and keeping it straight. You will feel a light stretch in the back of the thigh. To increase the stretch, push the leg further into the chair.