The authors conducted this preliminary study with the intention of demonstrating if it was feasible to evaluate variations in acceleration of trunk movement, pain, and disability during an episode of acute nonspecific low back pain comparing regular trunk exercises to regular exercises as well as core stability exercises. They used a pilot randomized controlled trial to evaluate 33 participants recruited from a National Health Service physiotherapy musculoskeletal provider in the London district of Hillingdon. Participants were separated into 2 groups; a regular exercise group (male, 2; female, 15) with a mean (SD) age of 35.8 (9.1) years and intervention group (male, 3; female, 13) with a mean (SD) age of 36.2 (9.8) years. The regular exercise group received exercise comprised of a core stability class including both specific and global trunk exercises. The intervention group, in addition to these core exercises, received further instruction on 8 specific stabilization muscles involving the transversus abdominis and the lumbar multifidus. Trunk sagittal acceleration, pain, and disability were measured using a Lumbar Motion Monitor, pain visual analog scale, and Roland Morris Disability Questionnaire, respectively. Measures were taken at baseline, 3 and 6 weeks, and a 3-month follow-up. Multiple regression with adjustment for baseline value was used to analyze each outcome. All outcomes were log transformed to correct skewness and so presented as ratio of geometric means with 95% confidence interval. Differences in mean trunk sagittal acceleration between the regular exercise and intervention groups was not statistically significant at any time point (ratio of means [95% confidence interval]: 3 weeks 1.2 [0.9-1.6], P = .2; 6 weeks 1.1 [0.8-1.5], P = .7; 3 months: 1.2 [0.8-1.9], P = .9). Similarly, the effects on neither pain score nor disability score were significant (pain score: 3 weeks 1.3 [0.8-2.2], P = .3); 6 weeks 1.2 [0.7-2.0], P = .6; 3 months 1.0 [0.5-1.9], P = 1.0); disability score: 6 weeks 1.0 [0.7-1.5], P = 1.0; 3 months 1.3 [0.8-1.9], P = .3). Outcome measures for both groups improved over time.
The authors were able to demonstrate with this preliminary study that a study of this nature is feasible. Both the regular exercise and the intervention groups demonstrated improvements in mean trunk sagittal acceleration at 3, 6, and 12 weeks. Their preliminary findings produced evidence that was inconclusive for the beneficial effect of adding specific core stability exercises for acute low back pain. The results of their study demonstrated an increase in acceleration accompanied by reduced pain, which may indicate that acute nonspecific low back pain may trigger the pain-spasm-pain model rather than the pain adaptation model.