GROUND REACTION FORCES DURING LONG JUMP TAKE-OFF FOR TRANSTIBIAL AMPUTEES

The purpose of this study was to investigate ground reaction forces during long jump take-off for lower limb amputees. Elite transtibial amputee (n=3) and able-bodied (n=6) athletes performed six running long jumps in an indoor athletics stadium with a force plate sunk into the runway. For each athletes’ longest jump, vertical (Fz) and horizontal (Fy) peak forces and impulses were calculated. The amputees had a shorter braking impulse duration, followed by a longer propulsive impulse duration with greater peak horizontal propulsive force and impulse than the able-bodied athletes. Vertical loading force and rate of force development at take-off was smaller for the amputees. It may be that amputees attempt to conserve as much horizontal velocity as possible by braking briefly, providing a longer duration in which to apply propulsive forces.