Immediate biomechanical, systemic, and interoceptive effects of myofascial release on the thoracic spine: a randomised controlled trial

Key points

1. 01MFR significantly increased thoracic range of motion versus both sham and control (F(2)=18.969, p<0.01, large effect size eta-p=0.633)
2. 02Pain pressure thresholds rose at local (thoracic back) and distal sites (neck and legs), indicating a systemic response beyond the treated area
3. 03Interoceptive sensitivity did not change significantly after MFR (F(2)=0.413, p=0.66), but baseline interoceptive sensitivity positively correlated with post-MFR range of motion (r=0.596, p<0.05)
4. 04Baseline interoceptive sensitivity showed a trend toward negative correlation with post-MFR pain pressure thresholds at cervical sites (r=-0.464 to -0.492), suggesting those more body-aware may experience lower pain thresholds
5. 05Study used triple-blind, randomised crossover design with sham control, strengthening internal validity despite the small sample

How it was conducted

Design

Triple-blind, randomised, sham-controlled, within-subjects crossover trial with one-week washout between conditions

Participants

12 asymptomatic first-year osteopathic students, ages 18-55, no prior spinal injury or recent manual therapy

Conditions

Three counterbalanced conditions: active MFR (thoracic erector spinae T6-T12 for 120 seconds), sham (hands resting on ribs for 2 minutes), and passive control (supine rest for 2 minutes)

Primary outcomes

Range of motion via digital inclinometer, pain pressure threshold via algometer at thoracic, cervical, and tibialis anterior sites, interoceptive sensitivity via heartbeat counting task and ECG

Analysis

Repeated-measures ANOVA on change scores, pairwise t-tests, and bivariate correlations between baseline interoceptive sensitivity and post-condition outcomes

What they found

• ROM: MFR produced a significantly larger change than both sham and control (F(2)=18.969, p<0.01, eta-p=0.633); pre-post MFR t(11)=6.35, p<0.01, Cohen's d=0.55 (large effect); control and sham pre-post changes were non-significant
• PPT left back: F(2)=0.534, p<0.001, eta-p=0.534; MFR vs control p<0.01, MFR vs sham p<0.01; pre-post MFR t(11)=-6.084, p<0.01, Cohen's d=0.388 (medium effect)
• PPT right back: F(2)=25.487, p<0.001, eta-p=0.699; MFR vs control p<0.01, MFR vs sham p<0.01; pre-post MFR t(11)=-5.063, p<0.01, Cohen's d=0.380 (medium effect)
• PPT left leg (distal): F(2)=12.398, p<0.001, eta-p=0.530; MFR vs control p<0.01, MFR vs sham p<0.01; pre-post MFR t(11)=-6.791, p<0.01, Cohen's d=0.24 (medium effect)
• PPT right leg (distal): F(2)=7.655, p<0.01, eta-p=0.410; MFR vs control p<0.05, MFR vs sham p<0.01
• PPT right neck: F(2)=10.857, p<0.01, eta-p=0.497; pre-post MFR t(11)=-5.218, p<0.001, Cohen's d=0.288 (medium effect)
• Interoceptive sensitivity: non-significant change across all conditions (F(2)=0.413, p=0.66, eta-p=0.036)
• Baseline IS correlated with post-MFR ROM: r=0.596, p<0.05; no significant correlation for sham (r=-0.369, p=0.238) or control (r=0.079, p=0.806)

Limitations

• Only 12 asymptomatic healthy participants; results may not generalise to clinical populations with pain or pathology
• Convenience sample with no a priori power calculation, raising risk of both false positives and underpowering
• Participants were prone during MFR but supine during control and sham, so position differences may have partially influenced outcomes
• Multiple simultaneous hypotheses increase the likelihood of a Type I error

Why it matters

For patients

A single thoracic MFR session may immediately reduce pain sensitivity and improve spinal mobility, but this has only been shown in healthy volunteers and needs confirmation in people with actual musculoskeletal pain.

For clinicians

The distal increases in pain pressure thresholds support a systemic neurological mechanism for MFR, and baseline interoceptive sensitivity may eventually serve as a predictor of treatment response, though clinical trials in symptomatic patients are needed first.

For readers

This small but well-controlled pilot demonstrates that MFR produces effects beyond the treated area, providing a basis for larger trials exploring how body awareness and autonomic pathways interact with manual therapy outcomes.