A standing complaint: Inability to sit: An unusual presentation of medial hamstring myofascial pain syndrome

Background: Hamstring muscle injuries are among the most common lower extremity injuries in athletes. Pain in the posterior thigh and leg weakness are usual presenting symptoms. Less dramatic onset in nonathletes, without pain in the posterior thigh, is more often thought of as an ischial bursitis or as pain from the sacroiliac joint or the gluteal or piriformis muscles. Pain localized over the ischial tuberosity resulting in disabling discomfort when sitting as the only symptom of medial hamstring muscle trigger points [TrPs] has not been reported before. Six cases of hamstring muscle myofascial pain syndrome are reported with this unusual presentation. Findings: Two cases were only single muscle syndromes, and in four cases other regional muscles also had TrPs that were symptomatic at some time. Only the ischiocondylar head of the adductor magnus [a false hamstring muscle] contributed to the inability to sit and it was not a consistent factor whereas the medial hamstring TrP was always present. The diagnosis was supported by the finding of localized tenderness in the proximal medial hamstring muscles [and also in the adductor magnus in two cases], and confirmed by diagnostic TrP injection of local anesthetic into the muscle. In each case, TrPs were located in the proximal portion of the muscle. Treatment of the medial hamstring muscles [including the adductor magnus muscle in the one case] produced a complete resolution or significant improvement in all cases. Conclusion: Medial hamstring muscle myofascial pain syndrome may present as a predominantly single muscle syndrome. Pain can be confined to the region of the ischial tuberosity, the only complaint being the inability to sit. Localization of TrPs in the proximal portion of muscle, above the tendinous band inscription of the muscle, may be a factor in proximal pain referral. Eccentric contraction, muscle fatigue, and inflexibility are factors that predispose to hamstring injury.