Paediatric perspective of biomechanical analysis of female gymnasts' landings: safety considerations

Long hours of gymnastics training, combined with the difficulty and complexity of skills, produce a considerable load on the musculo-skeletal system. Previous research (Snook, 1979; McNitt-Gray, 1991, 1993; Brueggemann, 1993; McNitt-Gray et. al., 1994) shows that modern women's artistic gymnastics has a high incidence of injury, especially in the lower extremities and the lumbar spine area. The purpose of this study was to measure the magnitude of the peak vertical ground reaction forces (PVGRF) during landing in selected skills performed on floor by junior female gymnasts. Subjects were 10 female sub-junior elite gymnasts from the Victoria Institute of Sport Women's Artistic Gymnastic Centre, and four Australian Gymnastics Federation level eight standard female gymnasts. Kinematics and kinetic data were captured on video (3-D) and force platform acquisition systems. Forces obtained via PVGRF indicate the load on the lumbar spine and this the likelihood of contributing to injury. The relationship between the PVGRF and the linear and angular kinematics is assessed to identify landing techniques that reduce PVGRF. Comparison of the analysed kinematic and PVGRF data of the VIS and level eight gymnasts performing the 'JSBLFP' indicated that higher PVGRF, longer landing phase times and greater knee and hip flexion were measured for the level eight gymnasts. The most crucial mechanical factors at landings are the maximum CM height before landing and the CM displacement from touch-down to the lowest CM position during landing. High loads and stresses placed on the lumbar region through repetitive 'solid' gymnastic landings over a long period of time, causes increased risk of injury to the lumbar spine