Special Test

Medial Hamstring Reflex

Last updated on: November 7, 2024

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The Medial hamstring reflex is mediated by tibial portion of the sciatic nerve, primarily by the L5 nerve root. It may be useful in the evaluation of suspected L5 radiculopathy.

How to perform the medial hamstring reflex?

To elicit the medial hamstring reflex, the patient is placed in the prone position. The examiner passes one hand underneath the patient’s leg and places the thumb of that hand on the semitendinosus tendon in the popliteal fossa. The patient’s leg is allowed to rest on the examiner’s forearm so that the patient’s knee is somewhat flexed. The examiner then strikes the thumb, which is pressing on the semitendinosus tendon, with the pointed end of the hammer. When the reflex is elicited, the examiner feels a contraction transmitted through the semitendinosus tendon or actually sees slight flexion of the knee take place.

See Also: Hamstring Muscles

This reflex can also be elicited by striking the semitendinosus and semimembranosus tendons just above their insertions on the tibia with the patient seated or recumbent, the leg abducted and slightly rotated externally, and the knee flexed. The examiner’s fingers are placed over the tendons on the medial posterior aspect of the knee and the fingers tapped with the reflex hammer. The response is knee flexion.

Reflex Name	Hamstrings Reflex
Muscle	Medial hamstrings
Patient Position	Prone with the knee slightly flexed looking away from the tested side
Position of Examiner	Standing or seated to the side of the patient. The thumb or finger is placed over the semitendinosus tendon immediately superior to the medial joint line.
Evaluative Procedure	The finger is tapped with the reflex hammer.
Innervation	Tibial nerve
Nerve Root	L5, S1, (S2)

A study founf that the medial hamstring reflex is precise and accurate in predicting radiculopathy of the fifth lumbar nerve root (L5). The Medial Hamstring Reflex should thus be formally included in the routine neurologic examination of a patient with a suspected L5 radiculopathy.

References & More

Jensen OH. The medial hamstring reflex in the level-diagnosis of a lumbar disc herniation. Clin Rheumatol. 1987 Dec;6(4):570-4. doi: 10.1007/BF02330595. PMID: 3449307. Pubmed
Esene IN, Meher A, Elzoghby MA, El-Bahy K, Kotb A, El-Hakim A. Diagnostic performance of the medial hamstring reflex in L5 radiculopathy. Surg Neurol Int. 2012;3:104. doi: 10.4103/2152-7806.100862. Epub 2012 Sep 13. PMID: 23087820; PMCID: PMC3475886. Pubmed
DeJong’s The Neurologic Examination – 8th Edition