The biceps femoris tendon is the distal continuation of the biceps femoris to the fibular head, where it forms the lateral hamstring cord palpable in the popliteal fossa. It is the most commonly strained hamstring at its proximal musculotendinous junction during sprinting, and distally it can be avulsed from the fibular head in contact sport. The common peroneal nerve runs immediately posterior to the distal biceps femoris tendon as it rounds the fibular neck.
Knee flexion and external tibial rotation force transmission; fibular head stabilisation
Proximal hamstring strains at the long head musculotendinous junction are the most common hamstring injuries in sprinting sports, producing posterior thigh pain with a palpable defect in severe cases. The MRI classification by the number of tendons involved (conjoint biceps-semitendinosus versus all three hamstrings) guides prognosis and return to play timelines. Complete avulsions from the ischial tuberosity with greater than 2 cm retraction require surgical repair.
Proximal musculotendinous junction tear during sprinting producing posterior thigh pain graded I to III by severity, with complete avulsions requiring surgical repair.
Fibular head tendon disruption in contact sport producing posterolateral knee instability with common peroneal nerve injury risk.
