The analysis of slalom-ski type movement using a ski-simulator apparatus

The research reported in this paper was designed to assess the feasibility of using a novel apparatus (a so-called ski-movement simulator) in the study of the acquisition of gross cyclical motor skills and further to develop analytic techniques appropriate to the movements involved. Three such methods are discussed: (1) the mean absolute deviation from the middle position as a measure of the ‘amplitude’ of the movement; (2) an auto-correlation coefficient as a measure of the ‘timing’ of the movement; (3) a cross-correlation coefficient as a measure of the ‘smoothness’ of the movement.Progress in learning - as shown by the measures of amplitude and smoothness- showed the expected trend, in that performance improved throughout the whole of the duration of the experiment (four consecutive days), but the rate of improvement gradually decreased. The largest effects were found for the ‘amplitude’ measure, which had the drawback that the ultimate level of performance was constrained by the body weight of the subject. The ‘smoothness’ measure did not suffer from this disadvantage and its suitability as a measure designed to evaluate gross skill acquisition in a laboratory situation is discussed.The ‘timing’ measure did not follow the same trend and reasons for this finding are proposed. Overall, it would seem that the different measures have varying usefulness in the study of skill acquisition and it is therefore advisable to study them separately.