Rocker shoes reduce Achilles tendon load in running and walking in patients with chronic Achilles tendinopathy

Objectives. Relative rest and pain relief play an important role in the management of Achilles tendinopathy, and might be achieved by reducing the load on the Achilles tendon. Previous studies have provided evidence that rocker shoes are able to decrease the ankle internal plantar flexion moment in healthy runners during walking and running. Since plantar flexion moment is related to the Achilles tendon loading, rocker shoes might be considered in the conservative management of Achilles tendinopathy. Therefore, the aim of this study was to investigate the biomechanics of running and walking in a group of patients with Achilles tendinopathy wearing standard shoes versus rocker shoes. Design. Cross-over. Methods. Thirteen Achilles tendinopathy patients (mean age 48 ± 14.5 years) underwent three-dimensional gait analysis wearing standard running shoes and rocker shoes during running and walking. Surface electromyography of triceps surae and tibialis anterior was recorded simultaneously. Results. Patients had symptoms for an average of 22.5 months (median 11.5 months) and VISA-A scores were 54 ± 16. With the rocker shoes, the peak plantar flexion moment was reduced by 13% in both running (0.28 N m/kg, p <0.001) and walking (0.20 N m/kg, p <0.001). The peak activity of tibialis anterior was increased by 35% (p = 0.015) for the rocker shoes in walking. There was no difference between electromyography peak amplitudes of triceps surae between two shoe sessions in both activities. Conclusions. When used by patients with chronic Achilles tendinopathy, rocker shoes cause a significant reduction in plantar flexion moment in the late stance phase of running and walking without substantial adaptations in triceps surae muscular activity. Keywords: Biomechanics; Kinetics; Kinematics; Footwear; Rocker sole; Rocker ba