Human Movement Science & Functional Anatomy of the:

Biceps Femoris (Lateral Hamstring)

by Brent Brookbush DPT, PT, COMT, MS, PES, CES, CSCS, ACSM H/FS

What’s in a name

  • biceps 1630s (adj.), from Latin biceps “having two parts,” literally “two-headed,” frombis“double” (see bis-) + -ceps comb. form of caput “head” (see capitulum). As a noun meaning “biceps muscle,” from 1640s, so called for its structure. Despite the -s, it is singular, and classicists insist there is no such word as bicep. (Etymology Online)
  • femur (n.) 1560s, from Latin femur “thigh, upper part of the thigh,” which is of unknown origin. (Etymology Online)
    • "Two headed muscles on the femur"

Biceps Femoris

  • Origin:
    • Long Head: Distal part of the sacrotuberous ligament and posterior part of the tuberosity of the ischium sharing a common tendon with the semitendinosus (8, 11, 22).
    • Short Head: Lateral lip of the linea aspera, proximal 2/3 of the supracondylar line (along with the middle portion of the adductor magnus), and lateral intermuscular septum (8, 11).
  • Insertion: The long head and short head of the biceps femoris share a common tendon that inserts on the lateral side of the head of the fibula, lateral condyle of the tibia, and deep fascia on the lateral side of the lower leg (8, 11, 23).
  • Nerve:
    • Long Head: Tibial nerve; a branch of the sciatic nerve via the sacral plexus, originating from nerve roots S1, S2, and sometimes L5 or S3 (8).
    • Short Head: Fibular nerve (peroneal nerve); a branch of the sciatic nerve via the sacral plexus, originating from nerve roots L5 – S2 (8).


Relative Location:

The long head of the biceps femoris originates from a shared tendon with the semitendinosus on the ischial tuberosity, with fibers extending to the sacrotuberous and sacrospinous ligaments. The origin of the long head of the biceps femoris, as well as the semitendinosus and semimembranosus is enveloped by the deep fascia of the posterior thigh (the fascia lata) which extends from the ischial tuberosity, underneath the large and thick gluteus maximus, and anteriorly to envelop the thigh. Frequently, a superior bursa i