A recent case-control study suggested that three months of targeted neck-specific exercises may normalize deep neck muscle function in individuals with chronic whiplash-associated disorders.
The study, published in Scientific Reports, used ultrasound with speckle-tracking analysis to measure muscle deformation during resistant neck rotation in participants with chronic whiplash-associated disorders (WAD) grades II and III, compared to healthy controls.
The study involved 34 participants with chronic WAD (26 women, 8 men, average age 41.3 years ± 10.6) and 34 age- and sex-matched healthy controls. On average, WAD participants were 26.4 months (± 13.4) post-injury. At baseline, the WAD group reported an average pain intensity of 46.0 mm (± 20.1) on the visual analogue scale (VAS; 0 = no pain, 100 = worst possible pain) and a neck disability of 39% (± 13.7) on the Neck Disability Index (NDI; 0% = no disability, 100% = maximum disability). In contrast, the control group reported minimal pain (1.6 mm ± 2.8 VAS) and neck disability (1.1% ± 1.6 NDI).
Initially, altered muscle deformation was observed in the three deepest neck muscle layers of WAD patients, particularly during rotation toward the most painful side. Significant differences in muscle deformation were identified between the WAD and control groups during right neck rotation across all five muscles (F(1,60) = 12.4, p < 0.001, ηp² = 0.17). Further analysis revealed significant variation in total deformation between the superficial muscles (trapezius, splenius) and the deeper muscles (semispinalis cervicis, multifidus) (F[1,60] = 9.6, p = 0.003, ηp² = 0.14). Interestingly, no significant differences were found between groups during left rotation at baseline.
Participants in the WAD group underwent either neck-specific exercises or neck-specific exercises with internet support for three months. Both interventions were analyzed as one group due to previous research showing similar outcomes. Following the exercise regimen, patients exhibited improvements in deep muscle function, with deformation patterns more closely resembling those of the control group. The differences in muscle deformation between the WAD and control groups were no longer significant. The intervention also led to marked decreases in neck disability (average reduction of 9.5%, ± 8.5, p < 0.001) and neck pain (average reduction of 18.9 mm, ± 25.2, p < 0.001).
The study explored the potential use of ultrasound in detecting altered muscle function in WAD and assessing rehabilitation outcomes. The findings suggested that improving muscle function through targeted exercises might help reduce persistent pain and disability in chronic WAD, even in patients with longstanding symptoms including neurological signs (WAD grade III). However, the authors acknowledged several limitations, including the need for further validation of the ultrasound method for dynamic exercises.
While these results are promising, further research is needed to confirm the diagnostic effectiveness of ultrasound imaging in WAD and its role in evaluating treatment outcomes. The study indicated that this non-invasive method could potentially become a valuable tool in the diagnosis and management of chronic WAD.
The authors reported no potential conflicts of interest.