Effect of 10-week core stabilization exercise training and detraining on pain-related outcomes in patients with clinical lumbar instability

Abstract

Background and aims: Clinical lumbar instability causes pain and socioeconomic suffering; however, an appropriate treatment for this condition is unknown. This article examines the effect of a 10 week core stabilization exercise (CSE) program and 3 month follow-up on pain-related outcomes in patients with clinical lumbar instability.

Methods: Forty-two participants with clinical lumbar instability of at least 3 months in duration were randomly allocated either to 10 weekly treatments with CSE or to a conventional group (CG) receiving trunk stretching exercises and hot pack. Pain-related outcomes including pain intensity during instability catch sign, functional disability, patient satisfaction, and health-related quality of life were measured at 10 weeks of intervention and 1 and 3 months after the last intervention session (follow-up); trunk muscle activation patterns measured by surface electromyography were measured at 10 weeks.

Results: CSE showed significantly greater reductions in all pain-related outcomes after 10 weeks and over the course of 3 month follow-up periods than those seen in the CG (P<0.01). Furthermore, CSE enhanced deep abdominal muscle activation better than in the CG (P<0.001), whereas the CG had deterioration of deep back muscle activation compared with the CSE group (P<0.01). For within-group comparison, CSE provided significant improvements in all pain-related outcomes over follow-up (P<0.01), whereas the CG demonstrated reduction in pain intensity during instability catch sign only at 10 weeks (P<0.01). In addition, CSE showed an improvement in deep abdominal muscle activation (P<0.01), whereas the CG revealed the deterioration of deep abdominal and back muscle activations (P<0.05).

Conclusion: Ten week CSE provides greater training and retention effects on pain-related outcomes and induced activation of deep abdominal muscles in patients with clinical lumbar instability compared with conventional treatment.

Keywords: clinical lumbar instability; core stabilization exercise; detraining effect; quality of life; trunk muscle activation.

Figure 1

Flow of participants through the study.

Figure 2

Ratio activation of transversus abdominis and internal oblique relative to rectus abdominis muscles (A) and ratio activation of lumbar multifidus relative to iliocostalis lumborum pars thoracis muscle (B) before and after intervention of core stabilization exercise (CSE) (n=21) and conventional group (CG) (n=21). Notes: *P<0.05 for difference between baseline and each follow-up value; **P<0.01 for difference between baseline and each follow-up value; ^aP<0.05 for difference in post value between groups; ^bP<0.001 for difference in post value between groups.

Figure 3

Mean and standard deviation of the normalized muscle activation level in the pre- and post-core stabilization exercise (n=21) and the pre- and post conventional group (n=21). Abbreviations: EMG, electromyography; RA, rectus abdominis; TrA, transversus abdominis; IO, internal oblique; ICLT, iliocostalis lumborum pars thoracis; LM, lumbar multifidus.