Isolated Rhabdomyolysis of the Infraspinatus Muscle Following the CrossFit "Sissy Test": A Report of Two Cases.

CASE: Following the completion of a CrossFit-style challenge (the "Sissy Test"), 2 patients presented with severe pain and swelling over the posterior aspect of the scapula. Magnetic resonance imaging demonstrated isolated edema of the infraspinatus muscle in both patients; the compartments were compressible. Neurovascular checks and observation of range of motion were performed. The patients were treated nonoperatively and were discharged with the diagnosis of overuse syndrome with rhabdomyolysis of the infraspinatus muscle.

CONCLUSION: With marked increase in the popularity of extreme fitness, monitoring for rhabdomyolysis and potential renal dysfunction is essential.