Effects of whole-body strength training on pain and strength in chronic low back pain. A Randomized controlled trial

BackgroundWhile specific types of exercise (e.g., core exercise) are recommended for the management of chronic low back pain (CLBP), little is known of the effects of whole-body strength training (WBST) on pain outcomes.ObjectiveThis randomized controlled trial investigated the effects of a WBST program on pain intensity, pain sensitivity, and core strength in CLBP patients.Methods45 Patients were assigned to an intervention group (IG) or active control group (CG). The IG completed 12 weeks of WBST (45 min/week) plus group training (45 min/week), while the CG only performed the group training. Pain intensity (numeric rating scale, NRS, 0-10), lumbar pressure pain thresholds (PPT, N/cm²), and isometric trunk flexion/extension strength (kg) were assessed baseline (T0), post-intervention (T1), and follow-up (T2, NRS only).Results32 Patients finished the intervention and were analyzed. For PPT, an interaction effect for 'time' × 'group' was observed (p = 0.048) and the IG showed improvements in PPT (T0 = 38.2 ± 21.1; T1 = 48.1 ± 29.1), while the CG showed no change. A main effect 'time' (p < 0.001) and no interaction effect (p = 0.737) was observed for NRS. In the IG, NRS was lower at T1 and T2 compared to T0 (T0 = 5.0 ± 1.7; T1 = 3.8 ± 1.7; T2 = 3.8 ± 1.5), while no difference was found in the CG. For core extension and flexion strength, main effects 'time' (p ≤ 0.001) and no interaction effects (p > 0.071) were observed, while strength increased only in the IG (extension: T0 = 60.0 ± 23.7; T1 = 74.4 ± 28.9; flexion: T0 = 40.3 ± 16.9; T1 = 48.5 ± 19.2). PPT correlated positively with trunk strength (r = 0.320-0.621).ConclusionWBST combined with group exercise improves lumbar pain sensitivity in CLBP patients and might therefore be considered as an efficient training option within rehabilitation programs.