The effectiveness of aerobic versus strengthening exercise therapy in individuals with chronic whiplash-associated disorder: a randomised single case experimental design study

Abstract

Purpose

Recent RCTs and meta-analyses compare the effectiveness of different types of exercise for chronic whiplash associated disorder (WAD). This study aimed to verify whether the results of these studies translate to statistically significant and clinically meaningful effects in individual participants.

Materials and methods

A series of replicated randomised single case experimental design studies (SCEDs) with A-B design (A: baseline, B: intervention). Eight participants with chronic WAD (8 female, mean [SD] age 47 [10] years) were randomised into one of four baseline durations (5, 8, 11, and 14 days) and to one of two eight-week exercise interventions (aerobic or strengthening). Daily measures of pain intensity, bothersomeness, and interference were collected during the baseline phase and the intervention phase.

Results

Visual analyses indicated that three participants in the aerobic exercise group meaningfully improved. No improvements were found in the strengthening group. Effect sizes favoured the aerobic exercise group, yet randomisation tests of pooled effects did not show a difference in between-intervention effectiveness.

Conclusion

Contrary to our expectations, three out of four participants were nearly pain-free at the end of the aerobic exercise intervention, whereas none of the participants in the strengthening group improved meaningfully. This suggests that aerobic exercise may be favourable for WAD.

Implications for Rehabilitation

• Our results suggest that aerobic exercises are favourable over strengthening exercises and may be the preferred option for patients with chronic WAD.

• We found substantial variability in self-reported outcomes within participants, clinicians should be aware of this in the judgement of treatment effectiveness.

Keywords:

• Neck pain
• chronic pain
• whiplash-associated disorder
• physiotherapy
• exercise therapy

Author contributions

RdZ conceived the design of the study, content, wrote the paper, and approved the final version. JN and JC contributed to the design of the study, and approved the final version of the paper. MS conceived the design of the study, content, and approved the final version of the manuscript. PO contributed to the data analysis, the revision of the manuscript, and approved the final version.

Disclosure statement

Jane Nikles has a commercial interest in N-of-1 Hub Pty Ltd, a consultancy company.

Data availability statement

Data can be made available upon request.

Additional information

Funding

This study was funded by the Faculty of Health and Behavioural Sciences, The University of Queensland.