Temporal effects of isometric contraction maneuvers on threshold sural amplitude

Am J Phys Med Rehabil. 2000 Jan-Feb;79(1):40-3. doi: 10.1097/00002060-200001000-00009.


Objective: To investigate the effect of isometric biceps brachii contraction and neck flexion on the time course of threshold sural amplitude.

Design: Twelve healthy subjects, who were asked to lie supine on an examination bench, performed 1 min of muscle contraction. The sural sensory nerve action potential was recorded before, immediately after, and at 2-min intervals after muscle contraction. The preexercise level of stimulus intensity remained unchanged for sural readings throughout the entire course of the experiment.

Results: The temporal changes in sensory nerve action potential amplitudes for both maneuvers were similar (P = 0.9734, two-way interaction). The mean sural amplitude after neck flexion increased from 6.0 +/- 2.9 microV (SD) to 10.6 +/- 6.6 microV (SD) 10 min after contraction. Similarly, mean sural amplitude increased from 6.5 +/- 1.8 microV (SD) to 14.5 +/- 9.7 microV (SD) 8 min after biceps brachii contraction. Statistical analysis performed using repeated measures with post hoc least significant difference showed a significant temporal effect in the two groups (P = 0.04).

Conclusion: The temporal responses of threshold sural amplitudes after isometric biceps brachii contraction and central reinforcement neck flexion maneuvers are nearly identical with regard to increase in the amplitude.

Publication types

  • Clinical Trial
  • Randomized Controlled Trial

MeSH terms

  • Action Potentials
  • Arm / physiology
  • Humans
  • Muscle Contraction / physiology*
  • Prospective Studies
  • Sural Nerve / physiology*