By Jordana Bieze Foster
A rocker bar proximally positioned on a running shoe can relieve tension on the Achilles tendon as well as reduce the force required of the calf muscles during walking and slow running, according to research from the Netherlands.
The findings could have implications for rehabilitation of runners with Achilles tendinosis, said Klaas Postema, MD, PhD, professor of rehabilitation medicine at the University of Groningen, who presented his group’s results at the ISPO World Congress in Hyderabad, India.
“With every step, there’s a lot of tension on the Achilles tendon. It’s not surprising that it hurts,” Postema said. “With a proximally placed rocker bar the ground reaction force moves proximally, and the lever arm is shorter, so the need for force from the calf muscles goes down.”
Postema and colleagues analyzed 16 recreational runners, all heel strikers, while walking and slow running (7 km/h) wearing a sport shoe with and without a rocker bar. At both speeds, the rocker-bar condition was associated with significant decreases in internal plantar flexion moment and ankle dorsiflexion motion during late stance. Spatiotemporal variables and hip and knee moments did not differ significantly between shoe conditions.
Postema K, Sobhani S, Vd Heuvel E, et al. A proximally placed rocker bar and external ankle moments during walking and slow speed running. Presented at International Society of Prosthetics and Orthotics 2013 World Congress, Hyderabad, India, February 2013.