Force Irregularity Following Maximal Effort: The After-Peak Reduction

Barbara M Doucet; Joni A Mettler; Lisa Griffin; Waneen Spirduso

doi:10.1177/0031512516661274

Force Irregularity Following Maximal Effort: The After-Peak Reduction

Percept Mot Skills. 2016 Aug;123(1):244-57. doi: 10.1177/0031512516661274.

Authors

Barbara M Doucet¹, Joni A Mettler², Lisa Griffin³, Waneen Spirduso³

Affiliations

¹ Department of Occupational Therapy, Louisiana State University Health Sciences Center, New Orleans, LA, USA bdouc3@lsuhsc.edu.
² Department of Health and Human Performance, Texas State University, San Marcos, TX, USA.
³ Department of Kinesiology and Health Education, University of Texas at Austin, Austin, TX, USA.

PMID: 27502241
DOI: 10.1177/0031512516661274

Abstract

Irregularities in force output are present throughout human movement and can impair task performance. We investigated the presence of a large force discontinuity (after-peak reduction, APR) that appeared immediately following peak in maximal effort ramp contractions performed with the thumb adductor and ankle dorsiflexor muscles in 25 young adult participants (76% males, 24% females; M age 24.4 years, SD = 7.1). The after-peak reduction displayed similar parameters in both muscle groups with comparable drops in force during the after-peak reduction minima (thumb adductor: 27.5 ± 7.5% maximal voluntary contraction; ankle dorsiflexor: 25.8 ± 6.2% maximal voluntary contraction). A trend for the presence of fewer after-peak reductions with successive ramp trials was observed, suggesting a learning effect. Further investigation should explore underlying neural mechanisms contributing to the after-peak reduction.

Keywords: fine motor coordination; force output; force variability; gross motor coordination; motor control.

MeSH terms

Adult
Ankle / physiology*
Female
Humans
Isometric Contraction / physiology
Male
Motor Activity / physiology*
Motor Skills / physiology*
Muscle, Skeletal / physiology*
Thumb / physiology*
Young Adult