Hamstring

Anatomy

Definition and function	The hamstrings are the muscles of the posterior thigh that are primarily in charge of knee flexion and thigh extension
Muscles	Biceps femoris, semimembranosus, semitendinosus
Innervation	Tibial and common fibular (peroneal) divisions of the sciatic nerve
Primary functions	Flexion of leg, extension of thigh, stabilization of knee and hip joints

Source Link

Orthopedic TTest

Hamstring Strength Test

Purpose: to locate hamstring strain

Procedure:

Patient is prone, and their knees are flexed around 70°
Therapist stabilizes the affected pelvis and the posterior tibia on the affected side
Assess Medial Hamstrings (semitendinosus and semimembranosus) – slightly internally rotate femur. Patient holds this position against gravity (Grade 3 strength). As patient holds the position, therapist attempts to extend the affected knee.

Positive Sign – pain deep in the hamstrings indicates strain in the semimembranosus muscle while pain that is more superficial indicates strain in the semitendinosus muscle

Assess Lateral Hamstring (biceps femoris) – slightly externally rotate patient’s femur and holds their knee in 70° flexion against gravity (Grade 3 strength). As patient holds the position, therapist attempts to extend the affected knee.

Positive Sign – pain in the lateral hamstrings indicates biceps femoris strain