Exercise therapy for whiplash-associated disorders: a systematic review and meta-analysis

Key points

1. 01Whiplash-associated disorder (WAD) is a cluster of neck symptoms after an acceleration-deceleration injury, and exercise therapy is a patient-active rehabilitation strategy usually supervised by a physiotherapist.
2. 02Of 27 included randomized studies (2,127 patients), only 5 could be pooled for neck pain and 4 for neck disability, mainly because most trials lacked a control group not receiving active treatment.
3. 03The pooled analysis found a significant effect of exercise on neck pain at 6 to 8 weeks but no significant effect at 10 to 12 weeks, and a significant medium-term effect on neck disability that was largely driven by a single study (Peolsson et al).
4. 04Heterogeneity in trauma type, timing since injury, outcome measures, and comparison groups prevented firm conclusions about which exercise method or timing works best.
5. 05The authors rate the evidence base as weak and call exercise a possibly better option than usual care or advice rather than a proven superior treatment.

How it was conducted

Design

Systematic review and random-effects meta-analysis of randomized controlled trials (PROSPERO CRD42017060356, PRISMA)

Search

PubMed, Scopus, and Cochrane from inception to January 13, 2020 plus hand search; 4,103 records, 2,921 abstracts screened, 100 full texts

Participants

27 included studies reporting data for 2,127 patients with whiplash-associated disorders

Intervention

Exercise therapy (varied programs, often physiotherapist-supervised) vs other treatments, placebo, no treatment, or waiting list

Outcomes

Neck pain intensity and neck disability, with risk of bias by Cochrane RoB 2.0

What they found

• 27 studies (2,127 patients) were included; meta-analysis was possible for 5 studies on neck pain and 4 studies on neck disability.
• Neck pain: the pooled random-effects analysis showed a significant effect of exercise at 6 to 8 weeks (n=3 studies) but no significant effect at 10 to 12 weeks (n=2 studies).
• Neck disability: the pooled analysis of 4 studies showed a significant medium-term effect, but this result was mainly driven by a single trial (Peolsson et al).
• Most of the 27 studies could not be pooled because they lacked a control group not also receiving active treatment; the authors judged the overall evidence base to be weak.

Limitations

• Only 5 of 27 studies could be meta-analyzed for pain and 4 for disability, and the disability result rested heavily on one trial.
• Many primary studies lacked an untreated control group, so the effect beyond the natural recovery course is unclear.
• Substantial heterogeneity in trauma type, time since injury, exercise protocols, and outcome measures limited direct comparisons.
• The review covered only post-traumatic neck pain (WAD), not chronic neck pain more broadly.

Why it matters

For patients

Doing supervised exercises for your neck after a whiplash injury may ease pain in the first couple of months and help with day-to-day neck function.

For clinicians

Exercise therapy is a reasonable active option for WAD, but the evidence is weak and does not yet specify the best method or timing.

For readers

Despite many published trials, the pooled evidence that exercise beats usual care for whiplash is thin and short-term.