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Neuromuscular adaptation during skill acquisition on a two degree-of-freedom target-acquisition task: isometric torque production.

Abstract：

:In this study we attempted to identify the principles that govern the changes in neural control that occur during repeated performance of a multiarticular coordination task. Eight participants produced isometric flexion/extension and pronation/supination torques at the radiohumeral joint, either in isolation (e.g., flexion) or in combination (e.g., flexion-supination), to acquire targets presented by a visual display. A cursor superimposed on the display provided feedback of the applied torques. During pre- and postpractice tests, the participants acquired targets in eight directions located either 3.6 cm (20% maximal voluntary contraction [MVC]) or 7.2 cm (40% MVC) from a neutral cursor position. On each of five consecutive days of practice the participants acquired targets located 5.4 cm (30% MVC) from the neutral position. EMG was recorded from eight muscles contributing to torque production about the radiohumeral joint during the pre- and posttests. Target-acquisition time decreased significantly with practice in most target directions and at both target torque levels. These performance improvements were primarily associated with increases in the peak rate of torque development after practice. At a muscular level, these changes were brought about by increases in the rates of recruitment of all agonist muscles. The spatiotemporal organization of muscle synergies was not significantly altered after practice. The observed adaptations appear to lead to performances that are generalizable to actions that require both greater and smaller joint torques than that practiced, and may be successfully recalled after a substantial period without practice. These results suggest that tasks in which performance is improved by increasing the rate of muscle activation, and thus the rate of joint torque development, may benefit in terms of the extent to which acquired levels of performance are maintained over time.

journal_name

J Neurophysiol

journal_title

Journal of neurophysiology

authors

Shemmell J,Forner M,Tresilian JR,Riek S,Barry BK,Carson RG

doi

10.1152/jn.00670.2004

subject

Has Abstract

pub_date

2005-11-01 00:00:00

pages

3046-57

issue

eissn

0022-3077

issn

1522-1598

pii

00670.2004

journal_volume

pub_type

临床试验,杂志文章

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Neuromuscular adaptation during skill acquisition on a two degree-of-freedom target-acquisition task: isometric torque production.