Sensorimotor control exercises (SCE) increase trunk stability by enhancing neuromuscular activity and strength, perhaps preventing low back pain (LBP). A trunk-specific intervention based on 4 exercises improved trunk stability, however a reduced set of 1 exercise may have similar effects and increase compliance concurrently.
Purpose: To assess the response of a standard training (SG) and a low volume set of sensorimotor control exercises (EG) on trunk function and compliance.
Methods: 29 healthy subjects were randomly allocated to SG (n=15) or EG (n=14). A trunk-specific SCE protocol (3 weeks) was completed which differed in training volume (SG: 4 exercises; EG: 1 exercise). Training intensities were identical (1 familiarization session/ 6 home-based sessions; 3 sets; 10 repetitions). Pre-post intervention (M1; M2) isokinetic mean peak torque was measured for trunk extension (30°/s) and rightward rotation (30°/s) in concentric (CON), eccentric (ECC) and perturbed eccentric (PECC) mode. During testing neuromuscular activity of Mm. erector spinae, latissimus dorsi, external/internal obliquus and rectus abdominis were recorded by sEMG and summarized subsequently: dorso left (DL), dorso right (DR), ventral right (VR) and ventral left (VL). Mean peak torque was normalized to body weight (Nm/kg), EMG data was normalized to concentric MVC (%). Compliance was assessed using a training diary (sessions per week). Data was analysed descriptively (mean±SD) and by using a repeated measures ANOVA (α = .05).
Results: Mean peak torque in CON/ECC extension and rotation showed no group differences. During PECC rotation, SG (M1: 2.3±0.3, M2: 2.5±0.2) showed a significant larger increase of mean peak torque compared to EG (M1: 2.5±0.3, M2: 2.7±0.3) (p=.035). Both groups showed a significant increase in EMG activity of DR muscles for unperturbed ECC rotation (SG M1: 93±18, M2: 118±10; EG M1: 83±9, M2: 121±17) (p &lt.001). In SG, DL (M1: 95±13, M2: 113±16) (p=.011) and VR (M1: 83±14, M2: 110±29) (p=.010) muscle activity improved significantly during ECC rotation. Overall compliance was 7±3 (SG) and 7±2 (EG) sessions.
Conclusion: Both protocols enhanced trunk function in terms of neuromuscular activity and mean peak torque in trunk rotation. LBP patients might benefit from a low volume approach due to improved time-efficiency.