Electronic Thesis and Dissertation Repository


Doctor of Philosophy


Physical Therapy


Dr Dave Walton


Concussions are a serious health concern in today’s active society. There are many contributing factors to concussions but one that is starting to draw significant attention is the potential role the neck muscles play in mitigating concussive forces. There is evidence that stronger neck muscles may decrease an individual’s concussion risk. In order to fully define this role, an appropriate outcome measure for assessing neck strength is required. Once this is established, methods of training to improve neck strength can be evaluated for their effect on neck strength and subsequently effect on concussion risk. This thesis included three studies. Chapter 2 was a within session and between session test-retest agreement of a novel multi-planar neck-strength and upper kinetic chain assessment protocol using a hand-held dynamometer in a healthy adult population. Chapter 3 examined this protocol to determine its preliminary validity. Due to the lack of an accepted ‘gold standard’ for neck strength assessment, the validity was examined using three a priori hypotheses; face validity, known groups validity and convergent validity using EMG muscle activity. Chapter 4 is a pilot study investigating the effects of a training program using a novel neuromuscular neck-training device that has theoretical rationale on how to improve neck function to decrease concussion risk. This investigation demonstrated the device to be safe and potentially effective at improving axial rotation strength. This study provided promising results to justify further fully powered studies with the device. The final chapter provides a summary of this thesis and provides direction and guidance for future research into further defining the role of the neck muscles in concussion.