Changes in Measures of Cervical Spine Function, Vestibulo-ocular Reflex, Dynamic Balance, and Divided Attention Following Sport-Related Concussion in Elite Youth Ice Hockey Players

Abstract

Background: Concussion is a commonly occurring injury. The extent to which the cervical spine, vestibulo-ocular reflex (VOR), dynamic balance, and divided attention are affected following concussion is not well understood.

Objectives: To evaluate acute changes in measures of (1) cervical spine function, (2) VOR function, (3) dynamic balance, and (4) tasks of divided attention in elite youth ice hockey players following a sport-related concussion.

Methods: In this prospective cohort study, elite 13- to 17-year-old ice hockey players completed cervical spine measures (cervical flexor endurance test, head perturbation test, anterolateral strength, cervical flexion rotation test, joint position error), VOR function tests (head thrust test, dynamic visual acuity [clinical and computerized]), dynamic balance tests (Functional Gait Assessment), and divided-attention tasks (walking-while-talking test) both in the preseason and following concussion.

Results: At least 1 test was completed by 69 of 97 (71%) players (a maximum of 55 for any 1 test) at both preseason and immediately following concussion (median, 4 days post concussion). After Bonferroni corrections (α = .00625), using Wilcoxon signed-rank tests, cervical spine measures were significantly worse following concussion compared to baseline (cervical flexor endurance test: z = -5.20, P<.001; anterolateral neck strength: z_left = -5.36, P<.001 and z_right = -5.45, P<.001; and head perturbation test: z = -4.36, P<.001). Time taken to complete a complex task of divided attention relative to normal walking speed was faster (improved) compared to the preseason (z = -2.59, P<.01). There was no change in VOR or dynamic balance following concussion.

Conclusion: Measures of cervical spine function and divided attention were altered following concussion. However, tests of VOR and dynamic balance were not significantly different from baseline. Future research to evaluate the mechanism underlying these changes is warranted. J Orthop Sports Phys Ther 2018;48(12):974-981. Epub 27 Jul 2018. doi:10.2519/jospt.2018.8258.

Keywords: cervical spine; concussion; dynamic visual acuity; ice hockey; vestibular; youth.