Gait analysis before and after achilles tendon surgical suture in a single-subject study: a case report.

Achilles tendon rupture is a disabling injury that requires a long recovery time. We describe a unique case of a 46-year-old male who had undergone gait analysis as part of a personal physical examination and who, 16 months later, ruptured his left Achilles tendon while running. With gait kinematic and kinetic data available both before and after his injury, we determined the residual gait asymmetries on his uninjured side and compared the pre- and postinjury measurements. We analyzed his gait at 1, 4, and 7 weeks after his return to full weightbearing. Compared with the preinjury values, at 7 weeks he had almost complete range of motion in his left ankle (-2%) and a slight increase in gait velocity (+6%) and cadence (+3%). The peak power of his injured ankle was 90% of its preinjury value. In contrast, the unaffected ankle was at 118%. These observations suggest that measuring the asymmetries of the gait cycle, especially at the beginning of rehabilitation, can be used to improve treatment. We had the patient strengthen his ankle using a stationary bicycle before he returned to running. Kinetics also appears to be more powerful than kinematics in detecting functional asymmetries associated with reduced calf strength, even 15 weeks after surgery. Gait analysis could be used to predict the effectiveness of rehabilitation protocols and help calibrate and monitor the return to sports participation while preventing overloading muscle and tendon syndromes.