Effect of Neck Muscle Fatigue on the Head Stabilization and Postural Control in Patients with Chronic Neck Pain---Implication for the Control Mechanisms and Rehabilitation Exercises

Chronic neck pain is a common musculoskeletal disorder. There are abundant spindles in the neck muscles which contribute to the proprioceptive input to the central nervous system (CNS). Previous studies have shown that patients with neck pain would demonstrate reduced cervicocephalic kinesthetic sensibility and poor ability to maintain the stable standing and gait. The neck muscle fatigue in the normal subjects would result in not only declined motion performance but also postural imbalance. Patients with chronic neck pain suffer from greater fatigability of the neck muscles than the healthy individuals. There are no studies to date exploring the effects of the neck muscle fatigue on the patients with chronic neck pain. This study will investigate the interaction between the chronic pain and muscle fatigue, i.e. two important factors affecting the proprioceptive input, and its links to the head stabilization and postural control. The efficacy of two exercise regimes designed to improve the endurance of the superficial or the deep neck muscles would also be discussed. In the first year, the young adults and patients with chronic neck pain would perform the voluntary head movements in the state of pre-fatigue, post-fatigue, and recovery. In the second year, similar groups perform the balance test of quiet standing under different levels of external perturbation in the different fatigue states. The aims of the two years are to examine the relationship between the fatigue measure and the head stabilization as well as the postural control respectively. In the third year, the young patients with chronic pain would be randomly assigned to either the endurance training group or the craniocervical flexion exercise group. The outcome of the two exercises in respect to the pain and fatigue level of the neck muscles as well as the balance function would be compared during the first arrival, end of training after eight weeks, and follow-up after six months. The major goal of this study is to get better understanding of the mechanism the CNS regulates the head stabilization and postural control under different physiological states. The results would help to clarify fatigue-related motion performance and to provide optimal rehabilitation programs.

Project ID:PC10007-1188
External Project ID:NSC100-2314-B182-030