Immediate changes in trunk muscle activation patterns during a lifting task following an abdominal drawing-in exercise in subjects with recurrent low back pain

BACKGROUND: The abdominal drawing-in exercise could help improve delayed transversus abdominis (TrA) activation during limb movement in subjects with recurrent low back pain (rLBP). However, little is known about whether the same effect is observed during lifting tasks in subjects with rLBP. OBJECTIVE: This study aimed to clarify whether a single session of abdominal drawing-in exercise could correct the altered trunk muscle activation patterns during a lifting task in subjects with rLBP. METHODS: Fifteen subjects with rLBP performed lifting tasks before and immediately after three sets of 10 repetitions of isolated TrA voluntary contractions. The time of onset and activation amplitude during the lifting tasks were measured by surface electromyography (EMG) and compared between the trials before and immediately after exercise. RESULTS: During lifting, the onset of internal abdominal oblique/TrA (IO/TrA) and multifidus activation occurred earlier, the EMG amplitude of IO/TrA increased, and the EMG amplitude of erector spinae and multifidus decreased, compared with the pre-exercise data. CONCLUSIONS: These results suggest a possibility that the abdominal drawing-in exercise might be effective in improving the muscle recruitment pattern in people with rLBP.