Faculty Collaboration Database

Brain areas associated with force steadiness and intensity during isometric ankle dorsiflexion in men and women. Exp Brain Res 2014 Oct;232(10):3133-45

Date

06/07/2014

Pubmed ID

24903120

Pubmed Central ID

PMC4172577

DOI

10.1007/s00221-014-3976-z

Scopus ID

2-s2.0-84912026358 (requires institutional sign-in at Scopus site)   31 Citations

Abstract

Although maintenance of steady contractions is required for many daily tasks, there is little understanding of brain areas that modulate lower limb force accuracy. Functional magnetic resonance imaging was used to determine brain areas associated with steadiness and force during static (isometric) lower limb target-matching contractions at low and high intensities. Fourteen young adults (6 men and 8 women; 27.1 ± 9.1 years) performed three sets of 16-s isometric contractions with the ankle dorsiflexor muscles at 10, 30, 50, and 70 % of maximal voluntary contraction (MVC). Percent signal changes (PSCs, %) of the blood oxygenation level-dependent response were extracted for each contraction using region of interest analysis. Mean PSC increased with contraction intensity in the contralateral primary motor area (M1), supplementary motor area, putamen, pallidum cingulate cortex, and ipsilateral cerebellum (p < 0.05). The amplitude of force fluctuations (standard deviation, SD) increased from 10 to 70 % MVC but relative to the mean force (coefficient of variation, CV %) was greatest at 10 % MVC. The CV of force was associated with PSC in the ipsilateral parietal lobule (r = -0.28), putamen (r = -0.29), insula (r = -0.33), and contralateral superior frontal gyrus (r = -0.33, p < 0.05). There were minimal sex differences in brain activation across the isometric motor tasks indicating men and women were similarly motivated and able to activate cortical motor centers during static tasks. Control of steady lower limb contractions involves cortical and subcortical motor areas in both men and women and provides insight into key areas for potential cortical plasticity with impaired or enhanced leg function.

Author List

Yoon T, Vanden Noven ML, Nielson KA, Hunter SK

Author

Kristy Nielson PhD Professor in the Psychology department at Marquette University

MESH terms used to index this publication - Major topics in bold

Adolescent
Adult
Ankle
Brain
Brain Mapping
Electromyography
Female
Humans
Isometric Contraction
Male
Motor Cortex
Muscle, Skeletal
Musculoskeletal Physiological Phenomena
Sex Characteristics
Young Adult