Kinematic and postural characteristics of sprint running on sloping surfaces.

The aim of this study was to identify the kinematic and postural characteristics associated with sprint running on uphill and downhill slopes of 3 degrees and on a horizontal surface. Eight male physical education students were filmed while sprinting maximally on an uphill-downhill platform under each of three conditions: (a) uphill at 3 degrees, (b) downhill at 3 degrees and (c) horizontal. Running speed, step rate, step length, step time, contact time, flight time and selected postural characteristics of the step cycle were analysed. Running speed was 9.2% faster (P < 0.05) during downhill and 3.0% slower (P < 0.05) during uphill compared with horizontal sprint running. During downhill and uphill sprint running, step length was the main contributor to the observed changes in running speed. It increased by 7.1% (P < 0.05) for downhill sprint running and was associated with significant changes in posture at touchdown and take-off. During uphill sprint running, step length decreased by 5.2% (P < 0.05), which was associated with significant changes in posture and reduced flight distance. Given the interaction between the acute changes in step length and posture when sprinting on a sloping surface, our findings suggest that such changes in posture may detract from the specificity of training on such surfaces. The chronic effects of training on such slopes on the kinematics and posture of horizontal sprint running are currently unclear.