Biochemical and Clinical Effects of McKenzie Therapy versus Muscle Endurance Exercises in Chronic Low-Back Pain

This study aimed to assess the effectiveness of McKenzie Extension Protocol (MEP), Static Back Extension Endurance (SBEE), and Dynamic Back Extension Endurance (DBEE) on patient outcomes (pain, functional disability, and general health status); and biomarkers of muscle status (creatinine kinase) and anti-inflammatory cytokines (IL-4 and IL-10) in patients with chronic LBP.  

Seventy-six patients with chronic LBP were randomly assigned to either MEP; SBEE; or DBEE group. MEP was based on McKenzie protocols involving a specific sequence of lumbosacral repeated movements in extension. SBEE involved five different low-back extensor muscle endurance protocols of increasing difficulty level. DBEE was a replica of SBEE, which used dynamic trunk posturing instead of the static posturing used in SBEE. Assessments were carried out at baseline, 3rd and 6th week of the study. Analysis of Variance (ANOVA), Repeated measures ANOVA, and Kruskal-Wallis test were used to compare data. 

Between-group comparisons showed that MEP had a significantly higher effect on pain (p = 0.009). SBEE had greater effect on IL-4 (p = 0.044) and IL-10 (p = 0.005) at week 3.  Also, SBEE led to a higher effect on IL-4 (p = 0.001) and IL-10 (p = 0.001) at week 6. The three interventions were comparable in their effects on other clinical outcomes at week 6 (p > 0.05). 

MEP and SBEE had comparable beneficial clinical effects in patients with chronic LBP. MEP produced a higher reduction in pain, while SBEE yielded greater alterations in biomarker concentrations. 

All interventions resulted in an increase in serum creatinine kinase but not at a level suggesting muscle damage or a marked inflammatory response, indicating that the interventions are safe at the cellular level.