Kinematic Perturbation in the Flexion-Extension Axis for Two Lumbar Rigs During a High Impact Jump Task

in Journal of Applied Biomechanics
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The measurement of lumbar spine motion is an important step for injury prevention research during complex and high impact activities, such as cricket fast bowling or javelin throwing. This study examined the performance of two designs of a lumbar rig, previously used in gait research, during a controlled high impact bench jump task. An 8-camera retro-reflective motion analysis system was used to track the lumbar rig. Eleven athletes completed the task wearing the two different lumbar rig designs. Flexion extension data were analyzed using a fast Fourier transformation to assess the signal power of these data during the impact phase of the jump. The lumbar rig featuring an increased and pliable base of support recorded moderately less signal power through the 0–60 Hz spectrum, with statistically less magnitudes at the 0–5 Hz (p = .039), 5–10 Hz (p = .005) and 10–20 Hz (p = .006) frequency bins. A lumbar rig of this design would seem likely to provide less noisy lumbar motion data during high impact tasks.

Marc R. Portus (Corresponding Author) is with the Sport Science Sport Medicine Unit, Cricket Australia Centre of Excellence, Brisbane; the Biomechanics Department, Australian Institute of Sport, Canberra; and the School of Sport Science, Exercise and Health, University of Western Australia, Perth, Australia. David G. Lloyd and Bruce C. Elliott are with the School of Sport Science, Exercise and Health, University of Western Australia, Perth, Australia. Neil L. Trama is with Athlete and Coach Services Technical Laboratory, Australian Institute of Sport, Canberra, Australia.