Abductor digiti quinti shuffleboard: a study in motor learning

The purposes of this study were as follows: (1) to refine prior studies by investigating one muscle which provided all the agonistic motion involved in a novel motor task, (2) the pinpoint the exact time during which motor activity contributed to the final task, (3) to study the electrical changes that occurred in that one muscle as it developed skill, and (4) to compare the results of this study with the previous studies in this series. The muscle chosen for this study was the abductor digiti quinti of the nondominant hand and the novel task involved propelling a small plastic disk into a specific target area. Electromyography and cinematography were used in data collection. No statistically significant differences were found in prelearning and postlearning data with regard to electrical activity, movement time or range of movement. These results support a hypothesis earlier proposed by Payton to the effect that all the the agonists which contribute to a skilled performance begin as a relatively undifferentiated mass of muscle; as learning takes place the various elements of this muscle mass are differentiated into prime movers and auxiliaries. The electrical activity remains essentially the same in the prime movers while a marked reduction is seen in the auxiliary muscles. A reinterpretation of several earlier studies is suggested.