The effect of fatigue on iliocostalis lumborum and superficial multifidus muscle activity in rowers

Background and purpose: Back injury is a common complaint amongst rowers. With long training hours muscle fatigue is an inevitable consequence which may be a precursor to injury. This study aims to explore the effects of fatigue on iliocostalis lumborum (IL) and superficial multifidus (SM) whilst rowing on a Concept 2C rowing ergometer (C2CRE). Method: Nineteen male athletes from Cardiff University Rowing Club were recruited fulfilling specific inclusion criteria (mean age 22yrs ± 3). Ethical approval was obtained from the institutions ethical committee. With bilateral EMG electrodes (IL and SM) attached Maximum Voluntary Contractions were collected followed by a 10 minute warm up on a C2CRE. Subjects subsequently performed a 7 stroke power test (pre fatigue condition) (Godfrey and Williams 2007). Subjects then rowed at a power rate of an average power rating from the 7 stroke power test. As soon as subjects power ratings fell below 85% of the average they stopped, and then immediately performed the 7 stroke power test whilst EMG data (IL and SM) was collected (post fatigue condition). Paired T tests reported differences between pre and post fatigue scores for IL and SM. Results: A non significant trend in IL between pre and post fatigue conditions (p=0.065) was noted with no significant difference in SM activity (p=0.196) Conclusion: This study has provided evidence that there is a difference in muscle activity between IL and SM following a fatiguing protocol, which may play an important role in the understanding of mechanisms leading to low back pain in rowers.