An investigation into the role of targeted resistance exercise for the deep neck flexors in chronic neck pain rehabilitation

Chronic neck pain (CNP) is a common and costly musculoskeletal condition with a lifetime prevalence of approximately 20% worldwide. In most cases the absence of structural deformity leads to a lack of specific diagnosis resulting in it being labelled as non-specific. Research has identified that due to its multi-factorial aetiology; multi-modal management interventions result in more beneficial long term outcomes. A muscular weakness, particularly of the deep neck flexor muscles is present in patients with CNP when compared to healthy counterparts. Clinical guidelines advocate the inclusion of active exercise, (including resistance exercise) as part of a multi-modal physiotherapy intervention for immediate and long-term improvements in isometric strength, reduced pain and perceived disability. Means of providing targeted resistance exercise to the deep neck flexors in patients with CNP outside of clinical and laboratory settings is lacking. The aim of this research study presented in this thesis was to investigate the role of targeted resistance exercise for the deep neck flexors in CNP rehabilitation. This research study was conducted in four main parts, two systematic reviews, and an examination of the feasibility and effect of a targeted resistance exercise program for the deep neck flexors using a novel deep neck flexor muscle strengthening tool known as “FLEXOR”, in healthy controls and as part of a multi-modal physiotherapy intervention for patients with CNP. An examination of the literature identified the effects of chronic pain on the cervical flexor musculature, as well as determining a FITT (frequency, intensity, time and type) exercise principle for resistance exercise in CNP. Feasibility studies using “FLEXOR” to deliver resistance exercise in a healthy population (n=22) and in patients with CNP (n=26) were conducted. Patients with CNP who used the “FLEXOR” device in conjunction with usual care physiotherapy had immediate and significant improvements in isometric strength, pain and perceived disability. Increases in isometric strength and reductions in pain were significantly different when compared to improvements made by patients who received usual care physiotherapy alone (p=0.01, p=0.02 respectively). A follow up descriptive study with trial participants provided further information on device and study design feasibility, as well as gaining insight into patient perceptions of the benefits of conducting resistance exercise independently for addressing any of the biopsychosocial issues of chronic pain. This project provides new insights into the feasibility, safety and potential benefits of targeted resistance exercise for the deep neck flexors as part of physiotherapy treatment in CNP management. These findings may guide future research and clinical decision making in treatment planning for patients with CNP.