Background and Objective: In recent years, management of patients with chronic low back pain has been focused on transversus abdominis and multifidus muscles. The evidences have demonstrated dysfunction of these muscles in these patients. This study was aimed to compare the usefulness of motor-control exercises and conventional exercises on the lumbar local stabilizing muscles thickness, activity limitation and pain in patients with chronic low back pain.
Materials and Methods: A double-blind, randomized clinical trial was conducted at Razmjo-Moghadam Physiotherapy Clinic, Zahedan University of Medical Sciences, in 2006-2007. Forty-nine patients with chronic low back pain were randomly assigned to either a motor-control (n=25) or a conventional exercise (classic abdominal and back extensor exercises) group (n=24). Before and after intervention, multifidus and abdominal muscles thickness (mm) was measured using a 7.5 MHz B-mode transducer ultrasound, pain and activity limitation (both ordinal) were assessed using visual analog scale and Back Performance Scale, respectively. A 16 session exercise program, for 8 weeks, twice weekly, and 30 minutes per session was performed for both groups. Independent T-test, Mann-Whitney, paired T-test and Wilcoxon tests were used for comparing the pre-treatment and post-treatment inter-group and intra-group test results, res pectively.
Results: The mean transversus abdominis thickness increased from 1.87±0.63 mm to 2.39±0.63 mm in the motor- control group and from 1.93±0.49 mm to 2.22±0.47 mm in the conventional group (P<0.0001). The mean multifidus thickness increased from 8.63±2.37 mm to 9.69±2.49 mm in the motor control group and from 8.83±1.53 mm to 9.26±1.56 mm in the conventional group (P<0.0001). There was no significant difference between the two groups after treatment with the exception of pain severity (P>0.05). More pain relief was achieved in motor- control group (P=0.015).
Conclusion: The results showed that both motor-control and conventional exercises can cause increase in transversus abdominis and multifidus thickness, lumbar mobility and pain reduction in patients with chronic low back pain with no signs of spinal instability. However, the motor control exercises are more effective than conventional exercises in pain reduction.