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Updated: Oct 7, 2026

Experimental Methods to Study Human Postural Control
08:12

Experimental Methods to Study Human Postural Control

Published on: September 11, 2019

Muscular contractions and their effect on the vertical ground reaction force during quiet stance--Part I: Hypothesis

G Pagnacco1, D G Heiss, E Oggero

  • 1Mechanical Engineering Department, School of Allied Medical Professions, Ohio State University, Columbus, OH 43210, USA.

Biomedical Sciences Instrumentation
|May 12, 2001
PubMed

Insights

New research suggests neuromuscular activity, not just cardiovascular forces, causes subtle vertical ground reaction force oscillations during quiet stance. This finding opens new avenues for studying posture and neuromuscular disorders.

Area of Science:

  • Biomechanics
  • Neuroscience
  • Human Physiology

Background:

  • The origin of vertical ground reaction force (vGRF) oscillations during quiet stance is debated, with cardiovascular influence widely accepted but not exclusively proven.
  • Existing research on postural control primarily focuses on macroscopic sway, leaving smaller endogenous force perturbations less understood.

Purpose of the Study:

  • To investigate a novel hypothesis that a distinct neuromuscular postural control system compensates for endogenous forces, contributing to vGRF oscillations.
  • To differentiate between cardiovascular and neuromuscular contributions to vGRF oscillations during quiet stance.

Main Methods:

  • Simultaneous recording of electrocardiogram (ECG), electromyogram (EMG) from multiple muscles, and vGRF in ten human subjects.
  • Experimental design to isolate and measure myoelectrical activity in response to cardiac-induced perturbations.

Main Results:

  • Experimental evidence confirmed hypothesized muscular activity in response to cardiac contraction and blood movement perturbations.
  • Electromyography signals were identified as genuine myoelectrical activity, not cardioelectric artifacts.
  • Distinct patterns of muscular activation were observed, correlating with vGRF oscillations.

Conclusions:

  • A neuromuscular postural control system actively contributes to vGRF oscillations during quiet stance.
  • This finding necessitates reconsidering the sole reliance on cardiovascular explanations for vGRF oscillations.
  • vGRF analysis can be extended to assess neuromuscular control and trunk musculature in clinical conditions.

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