Does having an external focus in immersive virtual reality increase range of motion in people with neck pain?

Background: When instructing exercises to improve Range of Motion (ROM), clinicians often create an internal focus of attention, while motor performance may improve more when using an external focus. Objectives: Using Virtual Reality (VR), we investigated the effect of tasks with an internal and external focus on maximal ROM in people with neck pain and explored whether this effect was associated with fear of movement. Method: In this cross-over experimental design study, the cervical ROM of 54 participants was measured while performing a target-seeking exercise in a VR-environment (external focus task) and during three maximal rotation and flexion-extension movements with the VR-headset on, without signal (internal focus task). The main statistical analysis included two dependent T-tests. Pearson correlation coefficients were calculated to investigate whether the differences in ROM in both conditions were correlated to fear of movement. Results: Maximal neck rotation was larger in the external focus condition than in the internal focus condition (mean difference: 26.4°, 95% CI [20.6, 32.3]; p < 0.001, d = 1.24). However, there was a difference favouring the internal focus condition for flexion-extension (mean difference: 8.2°, 95% CI [-14.9, −1.5]; p = 0.018, d = 0.33). The variability in ROM was not explained by variability in fear of movement (for all correlations p ≥ 0.197). Conclusion: An external focus resulted in a larger range of rotation, but our flexion-extension findings suggest that the task has to be specific to elicit such an effect. Further research, using a task that sufficiently elicits movement in all directions, is needed to determine the value of an external focus during exercise.