Trunk control in and out of an episode of recurrent low back pain in young adults during the Balance-Dexterity Task

We investigated motor control strategies utilized by individuals with recurrent low back pain (rLBP) during active pain and remission periods as well as by back-healthy controls using the Balance-Dexterity Task. Nineteen young adults with rLBP were tested first when they were in pain and then again in symptom remission, and 19 matched controls were also tested. Trunk kinematic coupling and muscle co-activation were examined while participants performed the task by standing on one leg while compressing a spring with a maximum consistent force with the other leg. We found a decreased bilateral external oblique co-activation during the spring condition of the task compared to the stable block condition in people with rLBP compared to back healthy individuals. There was also reduced trunk coupling during the spring condition of the task compared to the stable block condition in both the rLBP active and remission groups, but no group difference between rLBP and back-healthy individuals. When individuals were in active pain, they exhibited more co-activation than when they were in remission, but the co-activation during active pain was not greater than in back-healthy individuals.