The Effects of Changes in Task Conditions on the Temporal Organization of a Repetitive Speed Skill

Abstract The purpose of this study was to investigate the effects of changes in task conditions on the aerial organization of the response in a repetitive speed skill, hand cranking. It was hypothesized that one basic structure or programme could be used to meet a range of task conditions. Specifically the serial organization of the response was analysed under eight task conditions. Changes were made in the load or resistance to cranking, the handle radius and hence distance of movement, and direction of cranking, backwards and forwards in the sagittal plane. Motion photography, strain-gauge records of the force exerted and electromyography were used to record the on-going response. Serial organization was evaluated in terms of serial timing (sequencing and phasing) and positional timing. The results showed that on all treatment conditions phasing was central to the effective organization of the response. The effects of changes in task conditions were most noticeable on the positional timing criteria. Spe...