Efficacy of manual therapy on central sensitization in subjects with chronic low back pain: a systematic review and meta-analysis

Key points

1. 01Central sensitization is heightened central nervous system pain processing, measured here by pressure pain thresholds, temporal summation and conditioned pain modulation in areas away from the back.
2. 02Pooled across 6 studies, manual therapy had a negligible effect on central sensitization (effect size 0.01, confidence interval crossing zero).
3. 03Manual therapy showed a small but barely significant effect on peripheral (local) sensitization, with the lower confidence limit sitting exactly at zero.
4. 04Only one within-subject study (Khanmohammadi) found manual therapy raised remote pressure pain thresholds; the other five were non-significant.
5. 05Heterogeneity was high and the included trials varied widely in technique, dose and patient characteristics.

How it was conducted

Design

Systematic review and meta-analysis of clinical trials (RCTs, one-group and repeated-measures designs)

Search

PubMed, Scopus, ScienceDirect, Embase, CINAHL, CENTRAL, Web of Science, PEDro plus trial registries, 2000 to January 2023; 6 studies included

Participants

243 adults with chronic low back pain (3 or more months), more women than men, across 6 trials of 29 to 60 each

Intervention

Joint manual therapy (thrust manipulation or mobilization to lumbar or sacroiliac joints) vs sham, exercise, rehab or no treatment

Outcomes

Central sensitization (remote PPT, TS, CPM) as primary; peripheral sensitization (local PPT, TS) as secondary

Analysis

Random effects meta-analysis, Cohen's d standardized mean difference, PEDro quality scale, GRADE certainty

What they found

• Central sensitization (primary): pooled effect size 0.01 (95% CI -0.27 to 0.29), not significant; heterogeneity I-squared 58.5%, p = 0.004.
• Peripheral sensitization (secondary): pooled effect size 0.31 (95% CI 0.00 to 0.63); heterogeneity I-squared 78.8%, p < 0.001.
• No significant effect was found on pressure pain thresholds at various body areas, temporal summation, or conditioned pain modulation.
• PEDro quality scores ranged from 5 to 10 (one study scored 10, one scored 5).
• Only Bond et al and Khanmohammadi et al showed significant improvement in local pain sensitivity after manual therapy.

Limitations

• Only six studies with a small combined sample (243) and mixed designs, including one with no control group.
• Substantial heterogeneity in technique, dose, populations and outcome measures limits pooling.
• Only one study measured conditioned pain modulation, leaving descending pain inhibition poorly assessed.
• Studies using fMRI and soft-tissue or massage techniques were excluded, and long-term effects were not assessed.

Why it matters

For patients

Hands-on joint treatment for your back is unlikely to directly calm an over-sensitized nervous system, though it may still help as part of broader care.

For clinicians

Do not rely on joint manual therapy to reverse central sensitization in chronic low back pain; its effect on central mechanisms is unproven.

For readers

Current small-trial evidence shows no meaningful effect of joint manual therapy on central sensitization, with at most a weak signal on local sensitivity.