Objective To observe the effects of exercise-induced fatigue on the vestibular-oculomotor system using the VOMS (Vestibular Oculomotor Screen).

Design Repeated-measures, observational design

Setting Physiology laboratory (UK)

Participants 14 healthy amateur rugby athletes not in concussion protocol and 13 healthy sedentary participants not meeting the government guidelines for recommended exercise.

Interventions Baseline VOMS-measures were taken at rest. All participants understood a fatigue protocol. VOMS re-administered (≤ x2) unless still symptomatic. VOMS-measures taken (max=3).

Outcome Measures The independent variable was the group being tested under the fatigue protocol. The dependent variable was the VOMS-scores and symptoms observed pre- and post-fatigue protocol.

Main Results In the athlete group significant results for near-point convergence measurements comparing baseline to post-1 VOMS-test (t22=-4.597, p=0.001, 2-tailed) and post-2 VOMS-test (t23=-2.289, p=0.039, 2-tailed) post-exercise in the Athlete group. Our data showed normalisation of convergence measurements in post-3 VOMS-test and no significance (t24=0.752, p=0.486, 2-tailed). No significant differences were noted between a change in symptoms pre- and post-fatigue protocol for the VOMS. However, VOR-vertical was approaching significance for change in symptoms score (t₁₆=-1.836, p=0.089, 2-tailed). The sedentary control group exhibit a significant increase in symptoms with horizontal saccades (t₄=-2.193, p=0.049, 2-tailed) and vertical saccades (t₇=-2.258, p=0.043, 2-tailed) post-exercise in the post-1 VOMS-test. In the athletic group, exercise effected the near-point convergence measurements comparing baseline to post-1 VOMS-test (t22=-3.024, p=0.011, 2-tailed) and post-2 VOMS-test (t23=-3.710, p=0.03, 2-tailed).

Conclusions Exertional fatigue has an immediate effect on the VOMS-scores. Clinicians should exercise caution when interpreting the VOMS in a fatigued state.