Degradation of Cervical Joint Position Sense Following Muscular Fatigue in Humans

Study Design. Before and after intervention trials. Objective. To investigate the effect of cervical muscular fatigue on joint position sense. Summary of Background Data. Although fatigue-related degradation of proprioceptive acuity at lower and upper limbs is well documented, to date no study has investigated whether muscular fatigue induced at the neck could modify joint position sense. Methods. A total of 9 young healthy adults were asked to perform the cervicocephalic relocation test to the neutral head position, that is, to relocate the head on the trunk, as accurately as possible, after full active cervical rotation to the left and right sides. This experimental task was executed in 2 conditions of No fatigue and Fatigue of the scapula elevator muscles. Absolute and variable errors were used to assess the cervical joint repositioning accuracy and consistency, respectively. Results. Less accurate and less consistent repositioning performances were observed in Fatigue relative to No fatigue condition, as indicated by increased absolute and variable errors, respectively. Conclusion. Results of the present experiment evidence that cervical joint position sense, assessed through the cervicocephalic relocation test to the neutral head position, is degraded by muscular fatigue.