Effectiveness and optimal dosage of resistance training for chronic neck pain: a systematic review with a qualitative synthesis and meta-analysis

Purpose

Ranked 4th for global disability neck pain is experienced by up to 50% of the population annually and is more common than low back pain in office-based workers. Clinical guidelines recommend multimodal physiotherapy that includes resistance training exercise (RET) for the neck and shoulders. Although RET programmes exist with different objective and physical outcomes (e.g. cervical isometrics, craniocervical flexor retraining etc.) no evidence synthesis has compared their effectiveness. Equally, despite being highly cited the dosage (repetitions, frequency, load) of RET varies considerably between studies. The aim of this study is 

1) to evaluate the effectiveness of RET in chronic non-specific neck pain (CNSNP)

2) to determine an optimal dosage.

Effectiveness
RET is supported by “very low” to “moderate” quality of evidence. RET reduces pain and disability compared to non-exercise interventions although superiority of one RET programme over another is unclear.
Dosage
Low quality and clinical heterogeneity limited investigation of RET dosage. Different dosages of Motor Control exercises have not been explored.

Approach

A systematic review and data synthesis was conducted according to a published registered protocol (PROSPERO CRD42018096187). Using a sensitive topic-based search CINAHL, MEDLINE, EMBASE, PEDro, grey literature sources and key journals were searched from inception to November 2018 for randomised controlled trials, investigating RET on pain and/or disability in CNSNP. Two reviewers independently completed eligibility screening, data extraction, risk of bias assessment (Cochrane Risk of Bias Tool) and rated the overall strength of evidence using Grading of Recommendations Assessment, Development and Evaluation (GRADE). Data was tabulated for semi qualitative comparison and grouped according to intervention, outcome and time point to compare across studies. Meta-analysis was completed where clinical and statistically homogeneity existed.

Outcomes

24 studies were identified from 3066 citations (n=2126 participants). Pain and disability were assessed at < 24 hours to 3 years, with 22/24 studies investigating short term outcomes (>24 hours ≤ 3 months). Significant RET and comparator clinical heterogeneity limited meta-analysis. 15 different RET programmes were identified using the following types of exercise in isolation or combination:

  1. Motor Control Exercises. 
  2. Pillar Exercises.
  3. Segmental Exercises. 
  4. Upper Limb Exercises.

Motor Control exercises were most commonly investigated either in isolation or in combination with other exercise (n=15 studies).

Effectiveness: RET is supported by “very low” to “moderate” quality of evidence. RET reduces pain and disability compared to non-exercise interventions although superiority of one RET programme over another is unclear. “Low” to “moderate” quality evidence suggests combinations of Motor Control + Segmental Exercises have favourable outcomes on pain and disability regardless of comparator. Despite the promising results of Motor Control + Segmental exercises and the prevalence of Motor Control exercises these RET programmes have not been investigated on long term outcomes.

Dosage: Low quality and clinical heterogeneity limited investigation of RET dosage. Different dosages of Motor Control exercises have not been explored.

RET reduces pain and disability in CNSNP but the superiority of one programme cannot confidently be recommended. Combinations of Motor Control + Segmental exercises appear to be the most beneficial in the short term. Future research should investigate the effectiveness of Motor Control and Segmental exercise on long term outcomes and whether different dosages improves effectiveness.

Cost and savings

N/A.

Implications

Physiotherapists should use RET in the management of CNSNP. Until further research clarifies a specific RET programme and dosage, physiotherapists should actively involve patients in designing their exercise programmes but combinations of motor control and segmental exercises appear promising.

Top three learning points

  1. Based on low to moderate quality evidence combinations of motor control (low load exercise targeted at restoring normal quality of movement and neuromuscular function of the deep cervical muscles) and segmental exercises (exercises targeted at the ability of the larger, superficial cervical muscles to produce, transfer and absorb force) are most effective in reducing chronic neck pain and disability.
  2. Optimal dosage of resistance training exercise for chronic non-specific neck pain is unknown.
  3. Significant clinical heterogeneity exists amongst chronic non-specific neck pain trials and quality is often reduced due to imprecision and high risk of bias.

Fund acknowledgements

This work was completed as part of a Clinical Health Research MRes at the University of Birmingham, UK funded by Health Education England and National Institute for Health Research (HEE/ NIHR ICA Programme Pre-doctoral Clinical Academic Fellowship, Mr Jonathan Price, ICAPCAF-2018-01-117). The views expressed in this publication are those of the author(s) and not necessarily those of the NHS, the NIHR or the Department of Health and Social Care.

Additional notes

This work was presented at Physiotherapy UK 2019. 

The protocol is registered with PROSPERO (Registration number: CRD42018096187). The study has now been published (see references).

Please see the attached Innovations poster below. 

For further information about this work please contact Jonathan Price.

 

Reference(s): 

1.Carroll LJ, Hogg-Johnson S et al. Course and Prognostic Factors for Neck Pain in the General Population: Results of the Bone and Joint Decade 2000–2010 Task Force on Neck Pain and Its Associated Disorders. Spine. 2008;33(4S):S75-S82

2.Gross AR, Paquin JP et al. Exercises for mechanical neck disorders: A Cochrane review update. Man Ther. 2016;24:25-45

3.Price J, Rushton A et al. Effectiveness and optimal dosage of resistance training for chronic non-specific neck pain: a protocol for a systematic review with a qualitative synthesis and meta-analysis. BMJ Open. 2019;9(2):e025158

4.Spencer, S., A. Wolf and A. Rushton (2016). "Spinal-Exercise Prescription in Sport: Classifying Physical Training and Rehabilitation by Intention and Outcome." J Athl Train 51(8): 613-628.

5. Price J, Rushton A, Tyros I, Tyros V, Heneghan NR (2020) Effectiveness and optimal dosage of exercise training for chronic non-specific neck pain: A systematic review with a narrative synthesis. PLoS ONE 15(6): e0234511. https://doi.org/10.1371/journal.pone.0234511