Do physical interventions improve outcomes following concussion: a systematic review and meta-analysis?

Key points

1. 01Subthreshold aerobic exercise had a small to moderate effect on lowering symptom scores (SMD=0.43) but did not significantly reduce days to recovery (SMD=0.19, p=0.61).
2. 02Aerobic exercise did not worsen symptoms in either acute or persistent concussion presentations, which had previously been uncertain.
3. 03Individually tailored multimodal therapy (cervical, vestibular, and oculomotor) produced a moderate improvement in symptoms (SMD=0.63, p=0.02) in those with persistent symptoms.
4. 04Concussed individuals with persistent symptoms were approximately 3 times more likely to return to sport by 8 weeks with multimodal therapy (RR=3.29), though high heterogeneity (I2=83%) means this result was not statistically significant.
5. 05Evidence for stand-alone cervical or vestibular therapy alone was limited to single studies with mixed results.

How it was conducted

Design

Systematic review and meta-analysis of RCTs

Databases searched

Medline, CINAHL, Embase, SportDiscus, Cochrane Library, Scopus, PEDro (inception to September 2020)

Participants

647 participants aged 12-54 years across 12 included trials

Interventions

Subthreshold aerobic exercise, cervical therapy, vestibular therapy, oculomotor therapy, and individually tailored multimodal combinations

Primary outcomes

Days to symptom recovery or return to activity, and symptom severity scores

Quality assessment

PEDro scale; trials rated fair to excellent (scores 3-8/10); 7 of 12 trials rated good to excellent

What they found

• Subthreshold aerobic exercise vs control on symptom scores (5 trials): SMD=0.43 (95% CI 0.18 to 0.67, p=0.001, I2=0%), favouring exercise.
• Subthreshold aerobic exercise in acute presentations: SMD=0.38 (95% CI 0.01 to 0.74, p=0.04, I2=0%).
• Subthreshold aerobic exercise in persistent presentations: SMD=0.46 (95% CI 0.13 to 0.80, p=0.006, I2=0%).
• Subthreshold aerobic exercise vs control on days to recovery (2 trials): SMD=0.19 (95% CI -0.54 to 0.93, p=0.61, I2=52%), no significant difference.
• Individually tailored multimodal therapy vs control on symptom scores (2 trials): SMD=0.63 (95% CI 0.11 to 1.15, p=0.02, I2=0%).
• Multimodal therapy vs control on return to sport by 8 weeks (2 trials): RR=3.29 (95% CI 0.30 to 35.69, I2=83%), not statistically significant due to high heterogeneity.
• Reneker et al: intervention group recovered from symptoms 1.99 (95% CI 0.95 to 4.15) times faster and were cleared for return to sport 2.91 (95% CI 1.01 to 8.43) times faster than controls.
• Schneider et al: intervention group was 3.91 (95% CI 1.34 to 11.34) times more likely to be cleared for return to sport in 8 weeks.
• Vestibular therapy (Kleffelgaard et al): significant improvement on Dizziness Handicap Inventory (-8.7; 95% CI -16.6 to -0.9; p=0.03) but not on other symptom scales.
• Cervical manual therapy (Jensen et al): 3.2-point reduction on 100-point VAS vs 1.9-point increase in control group, not considered clinically significant.

Limitations

• Small number of trials for certain interventions (cervical, vestibular) prevented meta-analysis and limits conclusions for those modalities.
• Several individual trials had small sample sizes, introducing potential sampling error and bias in pooled estimates.
• Heterogeneity in definitions of recovery across studies (I2=83% for return-to-sport outcome) reduced the reliability of the multimodal pooled result.
• Post-intervention scores rather than change scores were used in most analyses because change scores were unavailable, providing weaker evidence of treatment effect.

Why it matters

For patients

If you have concussion symptoms lasting more than 2 weeks, asking your physiotherapist about a structured program combining neck, balance, and eye-movement exercises may help you return to sport and daily activities faster than rest alone.

For clinicians

Subthreshold aerobic exercise (at 80%-90% of symptom-exacerbation heart rate) is safe and modestly effective for symptom reduction across both acute and persistent presentations; individually tailored multimodal therapy targeting cervical, vestibular, and oculomotor deficits offers the strongest evidence for expediting return to sport in persistent cases.

For readers

This meta-analysis provides level-one evidence that physical rehabilitation, especially multimodal therapy personalised to the patient's deficits, is beneficial after concussion, moving clinical guidance beyond simple rest toward active, targeted management.