Hamstring Flexibility is important for knee extension, and hamstring muscles contracture causes the knee flexion deformity.
See Also: Thomas Test that is used to evaluate the flexibility of the hip flexor muscles.
The popliteal angle test is the most popular method reported in the literature for assessing hamstring Flexibility, especially in the presence of a knee flexion contracture.
Hamstring flexibility can also be assessed with a passive straight leg raise, while ensuring that the lumbar spine is flattened on the treatment table and the pelvis is stabilized. However, this method may be used only if there is full extension at the knee of the leg being examined. Normal hamstring length should allow 80–85 degrees of hip flexion when the knee is extended and the lumbar spine is flattened.
The cardinal sign of iliotibial contracture is the presence in a supine patient of an abduction contracture when the hip and knee are extended, which is eliminated when the hip and knee are flexed.
Other tests include the following:
Retinacula Test: The patient is placed in the side-lying position and the knee is fully flexed. This position tightens the ITB. The clinician applies a medial and oblique force to the patella with the thumbs. Approximately 0.5–1 cm of patella motion should be available.
Quadriceps Flexibility Test: Quadriceps flexibility is examined by placing the patient in prone position and passively flexing the knee, bringing the heel toward the buttocks. The lumbar spine is monitored and stabilized if necessary to prevent motion. The heel should touch the buttocks. An adaptively shortened rectus femoris is usually the structure that prevents this motion.
Rectus Femoris Muscle Test: Testing of the rectus femoris muscle is carried out in the supine position. The patient uses his or her hands to hold the unaffected leg in maximal flexion. The examiner flexes the knee of the affected leg, which is hanging over the end of the examination table. One can normally attain knee flexion over 90° easily while keeping the hip extended, but shortening of the rectus femoris muscle causes a decrease in knee flexion to less than 90°.
The hamstring muscles group consists of: Semitendinosus; Semimembranosus; Biceps femoris.
|Semitendinosus||Ischial tuberosity||Medial surface of superior part of tibia||Tibial division of sciatic nerve (L5, S1, and S2)||Extend hip joint; flex knee joint and rotate it medially; when hip and knee joints are flexed, can extend trunk.|
|Semimembranosus||Ischial tuberosity||Posterior part of medial condyle of tibia, reflected attachment forms oblique popliteal ligament to lateral femoral condyle||Tibial division of sciatic nerve (L5, S1, and S2)||Extend hip joint; flex knee joint and rotate it medially; when hip and knee joints are flexed, can extend trunk.|
|Biceps femoris||Long head: ischial tuberosity.|
Short head: linea aspera and lateral supracondylar line of femur
|Lateral side of head of fibula; tendon is split at this site by fibular collateral ligament of knee||Long head: tibial division of sciatic nerve (L5, S1, and S2).|
Short head: common fibular (peroneal) division of sciatic nerve (L5, S1, and S2
|Flexes knee joint and rotates it laterally; extends hip joint (e.g., when initiating a walking gait)|