HISTORY - A 68 year-old male marathoner began experiencing a “floppy left foot” which “slaps the ground” after running a distance of one-half mile while training for the New York Marathon. He notes that the symptoms are present for fifteen to twenty minutes after ceasing running, and will dissipate with rest. The patient related a skiing accident three months prior in which he suffered a left hamstring injury resulting in significant swelling and ecchymosis posteriorly from the thigh to the calf. He recalls having extreme difficulty with walking, but gradually improved enough to resume training. He also had noted numbness laterally in the left lower leg for two months. He presently denies leg pain. PHYSICAL EXAM - Examination in the office revealed a pleasant male, 68 years old, conversive and friendly. Inspecton of the posterior left leg revealed no acute ecchymosis or other signs of trauma. There was a palpable fullness in the musculotendinous junction of the hamstrings, and a defect in the muscle belly 22 cm proximal to the superior popliteal crease, in which a 6 cm by 6 cm mass can also be palpated. The patient had obvious weakness graded 3+/5 to resisted knee flexion compared to his right leg, 5/5. The strength of the left tibialis anterior muscle, left extensor hallucis longus muscle, and left gastrocnemius/soleus complex were graded 4/5 versus his right leg, 5/5. The patient struggled to attain 10 toe raises on the left leg, but reached 10 on the right leg without difficulty. Sensory exam revealed subjective numbness to light touch on the lateral aspect of the left calf and the dorsolateral aspect of the left foot. DTR's were 2+ at the bilateral patellar tendons, undetectable at the bilateral hamstring tendons, and asymmetric at the achilles tendons with the left graded 1+ and the right graded 2+. DIFFERENTIAL DIAGNOSIS Hamstring tear L5-S1 disc herniation Multiple sclerosis Exertional anterior compartment syndrome Common peroneal nerve entrapment syndrome TESTS AND RESULTS MRI Lumbar spine and left thigh - extensive complete hamstring tear involving the long head of the biceps femoris, the semimembranosus, and the semitendinosus muscles. Atrophy of the involved muscles. Hematoma formation with hemosiderin adjacent to, and tethering, the sciatic nerve. - no evidence of lumbar disc herniation. EMG left leg - absent conduction of the left sural nerve and the left superficial peroneal nerve. - decreased amplitude in motor testing of the left tibial nerve. FINAL DIAGNOSIS Left sciatic nerve neuropraxia secondary to hematoma and scar tissue formation from a prior hamstring tear TREATMENT Left sciatic nerve neurolysis Physical therapy Gradual return to activity following post-op recovery