Modification of movement patterns to accomodate to a change in surface compliance in a drop jumping task
1992; Elsevier BV; Volume: 11; Issue: 5 Linguagem: Inglês
10.1016/0167-9457(92)90017-6
ISSN1872-7646
AutoresRoss Sanders, Barry D. Wilson,
Tópico(s)Sports Dynamics and Biomechanics
ResumoThis study investigated changes in kinematics as subjects adapted to a change of surface compliance in a drop jumping task. It was hypothesised that changes in the pattern of centre of gravity acceleration with respect to the surface would be associated with improved performance. Six subjects performed 200 trials on a hard surface and then 190 trials on a compliant (sprung) surface. There was considerable improvement in height achieved (0.12 m to 0.41 m) by subjects during the sprung surface trials. With the exception of one subject, improvement was still occuring towards the end of the 190 trials on the sprung surface. The improvement in height was primarily due to improvements in the velocity of the centre of gravity with respect to the surface at last contact. In general, this was not achieved by increasing the displacement over which the centre of gravity could be accelerated with respect to the surface. The pattern of accelerations relative to the surface changed over the learning period and were directly related to improvement in performance as hypothesised. The Fourier spectra of the relative accelerations changed such that the amplitude of higher frequency harmonics increased with practice. There was a gradual shift in the angular kinematics away from the patterns associated with jumps from the hard surface. In particular, flexion of the ankle, knee, and hip following first contact decreased with increasing trials on the sprung surface.
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