I am reading this article for a journal club this week, so I thought I would create a summary in the format that Bret Contreras and Chris Beardsley do every month for their strength and conditioning research review. If you are interested, check it out here: http://www.strengthandconditioningresearch.com/
Efficacy of Trunk Balance Exercises for Individuals With Chronic Low Back Pain: A Randomized Clinical Trial. By Roberto Gatti et al. JOSPT August 2011
Motor control research has determined that trunk muscles do not activate properly after an individual has had an episode of low back pain. A result of this decreased activation are deficits in trunk balance and position sense as well as other measures of balance. Motor control training has been proven effective for low back pain, but trunk balance exercises to train the motor control system have not been evaluated.
What Did The Researchers Do?
The researchers took 79 individuals with chronic low back pain (>=3 months duration) and randomly divided them into 1 of 2 groups. Both groups exercised in groups of 4-6 2x/week for 5 weeks (for a total of 1o hours of exercise). The exercise sessions would include 15 min of treadmill walking, 30 min of flexibility exercises (anterior / posterior pelvic tilt, single knee to chest, double knee to chest, lower trunk rotation, adductor stretch, hamstring stretch, sidelying quad stretch, prone press up, seated trunk flexion, seated trunk rotation), and then the last 15 min would differentiate the two groups.
The experimental group performed balance exercises (tall kneeling trunk rotation, tall kneeling UE flexion / extension, bridge, birddog, sitting on a corner of a table with unilateral support, single leg kneeling on edge of table). The participants were instructed that exercises should be painfree and changed if they became painful. Progression of exercise included closing eyes, head movement and the use of unstable surfaces. The exact protocol for time performing the exercises is in the article.
The control group performed strength training exercises (abdominal curl up, shoulder extension, hamstring curl, leg extension). The resistance exercises were performed at 50% MVIC for 3 sets of 8 reps and the curl up was performed for 3 seconds for 3 sets of 6 reps.
Outcome measures included pain ratings, the Roland and Morris Questionnaire (RMQ) and the mental and physical components of the SF-12. A secondary outcome measure of impact on painful positions and use of pain relieving mediations was also included
Pain intensity decreased somewhat in both groups, but the quantity was very low and not different between groups. This was an insignificant finding.
The disability and quality of life scales also showed very small improvements. In these measurements there were some meaningful clinically important differences (MCID). For the RMQ, the improvement reached the MCID in 19 / 34 experimental subjects and 14/45 control group subjects. For the SF12 physical component 16 subjects in each group reached the MCID. For the SF12 mental component, changes were minimal.
The secondary outcome measures had interesting results in that 28/34 of the participants in the experimental group had decrease in painful positions where the improvement was only 27/45 in the control group.
What Were The Conclusions?
Trunk balance exercises were more effective than strengthening exercises in reducing disability and improving the physical component of the quality of life.
Lack of a follow up measure to determine if changes lasted. Possible placebo effect as the groups knew what they were doing. The most important one that I feel they mention is the fact that both groups participated in 45 minutes of exercise that was identical, so the similar results between groups may be due to that time exercising.
On a personal note, I feel that the selection of flexibility exercises could lead to more harm than good. I would prefer a lower load spinal stretch like the cat and camel rather than seated flexion, rotation, and prone press up.
Trunk balance exercises may be better for rehabilitating patients with chronic low back pain. These positions (variety of kneeling, quadruped, bridging) are common in the functional movement / exercise world and I think that integrating those positions into a workout is a great idea in terms of addressing back pain.