title: The accuracy of magnitude production of submaximal precision and power grips and gross motor efforts.
abstract: The objective of the study was to measure maximal and subjectively graded submaximal efforts in a pinch grip, power grip, and stoop life activity, subsequently to study the relationship of these efforts across activities and time, and furthermore to determine the reliability of effort perception of activities in different grades of operation. Ten normal male university students with mean age of 22.2 years, mean height of 175.3 cm, and mean weight of 71.4 kg volunteered for the study. All subjects were required to exert their maximal efforts, 80%, 60%, 40%, and 20% (of the maximal) effort in pinching, gripping and stoop lifting for three trials in a random order on four different days. The subjects were tested at the same time of the day on a Monday, Wednesday, Friday of one week, and Friday of the next week. While the activity and perception had significant main effects (p < 0.001) the trial was significant only for average strength (p < 0.04). There was a significant two-way interaction between activity and perception; all other interactions were not significant. There was a systematic bias in perception at all graded contractions except at 40% level of effort. The perceived 60% and 80% of maximal voluntary contractions (MVC) were lower and 20% was higher than their respective objective values based on MVC (p < 0.01). At 40% effort there was no statistical difference between perceived and objective strength effort in all three activities. The reliability of perception was similar for precision, power, or gross activity.
authors.affiliation: Department of Physical Therapy, University of Alberta, Edmonton, Canada.
authors.forename: S
authors.initials: S
authors.lastname: Kumar
authors.forename: M
authors.initials: M
authors.lastname: Simmonds
mesh_terms: D000328:Adult; D006801:Humans; D007537:Isometric Contraction; D008297:Male; D009132:Muscles / Q000502:physiology*; D015203:Reproducibility of Results; D013647:Task Performance and Analysis