Impact attenuation properties of jazz shoes alter lower limb joint stiffness during jump landings.

ABSTRACT

OBJECTIVES: To quantify the impact attenuation properties of the jazz shoes, and to investigate the in-vivo effect of four jazz shoe designs on lower limb joint stiffness during a dance-specific jump. DESIGN: Repeated measures. METHODS: A custom-built mechanical shoe tester similar to that used by athletic shoe companies was used to vertically impact the forefoot and heel region of four different jazz shoe designs. Additionally, dancers performed eight sautés in second position in bare feet and the shoe conditions. Force platforms and 3D-motion capture were used to analyse the joint stiffness of the midfoot, ankle, knee and hip during the jump landings. RESULTS: Mechanical testing of the jazz shoes revealed significant differences in impact attenuation characteristics among each of the jazz shoe designs. Gross knee and midfoot joint stiffness were significantly affected by the jazz shoe designs in the dancers' jump landings. CONCLUSIONS: The tested jazz shoe designs altered the impact attenuating capacity of jump landing technique in dancers. The cushioned jazz shoes are recommended particularly for injured dancers to reduce impact on the lower limb. Jazz shoe design should consider the impact attenuation properties of the forefoot region, due to the toe-strike landing technique in dance movement.