Proximal and distal muscle fatigue differentially affect movement coordination

PLoS One. 2017 Feb 24;12(2):e0172835. doi: 10.1371/journal.pone.0172835. eCollection 2017.

Abstract

Muscle fatigue can cause people to change their movement patterns and these changes could contribute to acute or overuse injuries. However, these effects depend on which muscles are fatigued. The purpose of this study was to determine the differential effects of proximal and distal upper extremity muscle fatigue on repetitive movements. Fourteen subjects completed a repetitive ratcheting task before and after a fatigue protocol on separate days. The fatigue protocol either fatigued the proximal (shoulder flexor) or distal (finger flexor) muscles. Pre/Post changes in trunk, shoulder, elbow, and wrist kinematics were compared to determine how proximal and distal fatigue affected multi-joint movement patterns and variability. Proximal fatigue caused a significant increase (7°, p < 0.005) in trunk lean and velocity, reduced humeral elevation (11°, p < 0.005), and increased elbow flexion (4°, p < 0.01). In contrast, distal fatigue caused small but significant changes in trunk angles (2°, p < 0.05), increased velocity of wrench movement relative to the hand (17°/s, p < 0.001), and earlier wrist extension (4%, p < 0.005). Movement variability increased at proximal joints but not distal joints after both fatigue protocols (p < 0.05). Varying movements at proximal joints may help people adapt to fatigue at either proximal or distal joints. The identified differences between proximal and distal muscle fatigue adaptations could facilitate risk assessment of occupational tasks.

MeSH terms

  • Adolescent
  • Adult
  • Analysis of Variance
  • Arm / physiology
  • Biomechanical Phenomena
  • Body Mass Index
  • Elbow / physiology
  • Elbow Joint / physiology
  • Electromyography
  • Female
  • Hand / physiology
  • Humans
  • Male
  • Middle Aged
  • Movement / physiology*
  • Muscle Fatigue / physiology*
  • Psychomotor Performance / physiology
  • Risk Assessment
  • Shoulder / physiology
  • Shoulder Joint / physiology*
  • Wrist / physiology
  • Wrist Joint / physiology
  • Young Adult

Grants and funding

Funding was provided by a Graduate Research Grant from the University of Michigan. D.G. was supported by the Eunice Kennedy Shriver National Institute of Child Health & Human Development of the National Institutes of Health under Award Number K12HD073945. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.