Recurrence of Low Back Pain after an Initial Acute Episode

It is reassuring that most acute episodes of low back pain resolve within 2-4 weeks. [Spine (2001) 26 (11): E243-E248] While symptoms may get better for a time, as all too many of us know back pain does not always come for a single episode and then go away forever.

Recurrence rates after a single episode of back pain are staggeringly high, with 60 to 86% of patients reporting recurrent back pain symptoms.  [Spine (2001) 26 (11): E243-E248] A study by Berquist-Ullman and Larson followed injured workers for a year after an acute episode of back pain. They found that the initial episode had a median duration of 35 days. What is more striking, they found that 62% of the patients experienced at least one episode of recurrent low back pain and 36 % experienced two or more recurrences. The median time from resolution of the initial episode to the first recurrence was 2 months. [Spine (2001) 26 (11): E243-E248]

So people with acute low back pain face a high risk for recurrence of pain symptoms, especially during the first year after an acute episode. The reason for this likely explained by Panjabi’s model of spine stability, with the proposition that dynamic instability is created in a spinal segment with injury, degenerative disc disease and muscle weakness. [Spine (2001) 26 (11): E243-E248]

A study by Hides et al., however, demonstrated profound effects of specific stabilizing exercises for the prevention of future symptoms after a single acute episode of low back pain. [Spine (2001) 26 (11): E243-E248] In the study patients were educated on the performance of abdominal bracing exercises (based on co-contraction of the multifidus muscles in the back and the transversus abdominus muscle). The study followed patients for a total of three years after this initial acute episode. Patient’s that were educated in this abdominal bracing exercise during the first year had a recurrence rate of 30% in comparison with 84% in patients managed with more traditional medical management (rest, medication management of symptoms). Two to three years after the initial 4 week treatment, specific exercise group recurrence was 35% versus 75% recurrence in the control group.

Impressive for a relatively small intervention. So what is this exercise we should do after (or even before it could be argued) an episode of back pain – abdominal bracing.

Stuart McGill, a reknowned investigator in the field of exercise science refers to this muscle stiffening and terms it “abdominal bracing.” (Arch Phys Med Rehabil. 2007 Jan;88(1):54-62.) He teaches this technique with “full abdominal co-contraction.”

The basic goal of abdominal bracing exercises is to stiffen the abdominal wall with a mild isometric co-contraction of all the muscles around the core.　 With this co-contraction of muscles there should be no movement in the spine or pelvis and the abdominal wall is neither sucked in nor pushed out. The muscles involved in this co-contraction include the transverse abdominis, internal and external obliques, rectus abdominis, quadratus lumborum, erector spinae, and multifidi.

Refer to http://digg.com/d31LPR7 for a for full discussion of the how-to for abdominal bracing exercises.