Investigating the distribution of back muscle activity during a fatiguing task in people with low back pain

Abstract

People with chronic low back pain (CLBP) move differently and display changes in the activity of their back muscles, which may have implications for ongoing symptoms. Utilising a novel method to measure the distribution of back muscle activity, we investigated whether people with CLBP engage different regions of their back muscles during a sustained contraction. Back muscle activity was recorded from 13 people with CLBP and 13 healthy control participants as they completed a timed back extension endurance test until task failure. People with CLBP sustained the contraction for 95.6s less than the control participants. During the task, CLBP participants showed a lower level of activation of their back muscles and a lower level of redistribution of muscle activity over the task duration. These results show that the CLBP group used a different muscle strategy to perform the task, which may have relevance for ongoing pain and more rapid fatigue.