The effect of muscle fatigue on wrist joint position sense in healthy adults.

STUDY DESIGN

Pretest and posttest experimental study.

INTRODUCTION

The effect of muscle fatigue on wrist joint position sense (JPS) has yet to be determined.

PURPOSE OF THE STUDY

The primary aim was to determine whether muscle fatigue affects wrist JPS in healthy adults. The secondary aims were to compare the effect of muscle fatigue on younger and older adults JPS and determine the association between JPS rate of change and total muscle fatigue (TMF) rates postexercise.

METHODS

Forty male and female healthy adults were assigned into younger (18-40 years) and older (41-65 years) groups. Preexercise and postexercise testing consisted of active wrist JPS, handgrip, and wrist extensor strength assessments. Muscle fatigue was induced via a calibrated gripper and wrist extension dumbbell exercises. Dependent variables were the JPS rate of change (ie, preexercise and postexercise), TMF rate (ie, grip and wrist extension average strength decline), and Borg Rating of Perceived Exertion scale scores.

RESULTS

Postexercise wrist JPS test scores were significantly higher than preexercise. Exercises induced statistically significant TMF rates and Borg Rating of Perceived Exertion scores among all participants. No statistically significant age-group differences on JPS rate of change, and TMF rate was found. A statistically significant mild correlation (r = 0.425) existed between JPS rate of change and TMF rates.

DISCUSSION

Postexercise fatigue significantly impairs wrist JPS in both younger and older adults. On average, an 18% muscle strength decline led to 215% wrist JPS deficit.

CONCLUSIONS

Significant wrist proprioception deficits persist for ≤5 min following exertional exercises, regardless of age level.