MECHANISM OF LANDING STRATERGY DURING STEP AEROBICS WITH DIFFERENT BENCH HEIGHTS AND LOADS

The purpose of this study was to investigate effects of different heights (6inch, 8inch, 10inch) and external loads (0% BW, 10% BW, 15% BW) on lower extremity during step aerobics. Ten college physical education students (age: 23.8 ± 2.1 years, height: 173.5 ± 6.1 cm, weight: 68.5 ± 8.0 kg) participated in this study. A Mega high-speed camera (100 Hz) and an ATMI force plate (1000Hz) were used to record kinematic and kinetic data respectively during step aerobics. Increased vertical ground reaction force, ankle movement, and decreased leg stiffness and ankle joint stiffness were found as the bench height increased to 10 inches which were considered to a high loading rates and shock to the lower extremity, especially at ankle joint. Therefore, people should avoid doing step aerobics at 10-inch bench height for a long time to protect ankle joint and soft tissue from injury