We often find clinically that the quadratus femoris as becoming the 1st dysfunctional muscle of the deep 6 external rotators (1) and its pain referral pattern can mimic the piriformis (2) and piriformis syndrome (3) as well as hamstring insertional tendinitis. It has also been implicated in some cases of femoroacetabular impingement (4) as well as ishiofemoral impingement (5). It is active during walking stance phase, and moreso during stance while running as well as with a clamshell exercise with external rotation (6). It appears to be maximally lengthened with flexion and adduction or abduction, with internal rotation ( a great position of you need to stretch this muscle), and is deducted to be strongest going from a 60-90 degree flexed position into extension (ie: it has the with the largest moment arms observed for extension in the deduced force-length efficient range of 60-90° flexion)(7).
Needling this muscle can sometimes pose a challenge. Here is a demo of one way to accomplish it I often employ while needling some of the other surrounding hip musculature.
Consider the QF the next time you have someone with hamstring insertional pain, or diffuse hip pain that you are having a difficult time localizing.
- Personal observation
- Janet G. Travell , M.D., and David G. Simons, M.D., Myofascial Pain and Dysfunction: The Trigger Point Manual, The Lower Extremities vol. 2 (Baltimore: Williams & Wilkins, 1992) pp. 186-193.
Diamond LE, Van den Hoorn W, Bennell KL, Wrigley TV, Hinman RS, O'Donnell J, Hodges PW. Coordination of deep hip muscle activity is altered in symptomatic femoroacetabular impingement. J Orthop Res. 2016 Aug 11. doi: 10.1002/jor.23391. [Epub ahead of print]
Semciw, Adam I. et al. Quadratus femoris: An EMG investigation during walking and running Journal of Biomechanics , Volume 48 , Issue 12 , 3433 - 3439
Vaarbakken K, Steen H, Samuelsen G, Dahl HA, Leergaard TB, Stuge B .Primary functions of the quadratus femoris and obturator externus muscles indicated from lengths and moment arms measured in mobilized cadavers. Clin Biomech (Bristol, Avon). 2015 Mar;30(3):231-7. doi: 10.1016/j.clinbiomech.2015.02.004. Epub 2015 Feb 11.