Discriminant analysis of neuromuscular variables in chronic low back pain

Abstract

Background:

Investigation and discrimination of neuromuscular variables related to the complex aetiology of low back pain could contribute to clarifying the factors associated with symptoms.

Objective:

Analysing the discriminative power of neuromuscular variables in low back pain.

Methods:

This study compared muscle endurance, proprioception and isometric trunk assessments between women with low back pain (LBP, $\mathit{n}=14$ ) and a control group (CG, $\mathit{n}=14$ ). Multivariate analysis of variance and discriminant analysis of the data were performed.

Results:

The muscle endurance time (s) was shorter in the LBP group than in the CG ( $\mathit{p}=0.004$ ) with values of 85.81 (37.79) and 134.25 (43.88), respectively. The peak torque (Nm/kg) for trunk extension was 2.48 (0.69) in the LBP group and 3.56 (0.88) in the GG ( $\mathit{p}=0.001$ ); for trunk flexion, the mean torque was 1.49 (0.40) in the LBP group and 1.85 (0.39) in the CG ( $\mathit{p}=0.023$ ). The repositioning error (degrees) before the endurance test was 2.66 (1.36) in the LBP group and 2.41 (1.46) in the CG ( $\mathit{p}=0.664$ ), and after the endurance test, it was 2.95 (1.94) in the LBP group and 2.00 (1.16) in the CG ( $\mathit{p}=0.06$ ). Furthermore, the variables showed discrimination between the groups ( $\mathit{p}=0.007$ ), with 78.6% of the individuals with low back pain correctly classified in the LBP group. In turn, variables related to muscle activation showed no difference in discrimination between the groups ( $\mathit{p}=0.369$ ).

Conclusion:

Based on these findings, the clinical management of low back pain should consist of both resistance and strength training, particularly in the extensor muscles.