Dose response of neural mobilization on hamstring flexibility in patients with non-specific low back pain: a randomized control trial

Abstract

Background: Non-specific low back pain (NSLBP) often correlates with reduced hamstring flexibility, contributing to altered biomechanics and recurrent symptoms. Neural mobilization (NM) techniques are increasingly integrated into management strategies to address neurogenic inflammation and neural tissue mobility. However, the dose-response relationship of NM for hamstring flexibility remains unclear, with limited studies isolating dosage effects amid multimodal interventions. 

Objectives: to determine the dose-response effect of NM on hamstring flexibility, pain, and disability in NSLBP patients, comparing high-dose versus low-dose protocols over a 4-week intervention. Methodology: A single-blinded randomized controlled trial allocated 34 NSLBP patients (aged 18–40) to Group A (High-dose NM) and Group B (Low-dose NM. The outcomes (NPRS for pain, ODI for disability, AKE test for flexibility) were assessed at baseline, 2 weeks, and 4 weeks. 

Results: Group A showed a significantly greater reduction at 2 weeks (p=0.007, d=0.58), though differences became non-significant by week 4. At the same time, Group A demonstrated superior reductions at both 2 weeks (p=0.0316, d=1.06) and 4 weeks (p<0.001, d=2.01). Finally, both groups improved equally in AKE (p≥0.05 between groups). 

Conclusion: High-dose NM provides acute advantages for pain and disability reduction, However, equivalent hamstring flexibility gains across doses suggest that concurrent stretching dominates flexibility outcomes, overshadowing NM's dose-dependent effects.