Multifidus muscle size and symmetry among elite weightlifters

Objectives: To examine muscle cross-sectional areas (CSA) and symmetry of lumbar multifidus (LM) muscles in elite weightlifters. Design: Cross-sectional observational study Setting: Neuromuscular and Pain Research Unit. Participants: Thirty-one elite weightlifters (15 males) participated in the study, representing the population of Thai weightlifters eligible for national selection. Main outcome measures: Resting CSA of the LM muscle were assessed bilaterally at 4 lumbar vertebral levels using ultrasound imaging. The between side differences (relative to the side of the preferred hand) were used to determine the asymmetry. Results: The between side differences (relative to the preferred hand) of the LM muscle CSA were less than 3% for all vertebral levels and suggested symmetry between sides (p > .05). No difference was found between weightlifters with unilateral or bilateral pain symptoms. Conclusion: This study provides new information on resting CSA for the LM muscle in elite weightlifters. Future studies could investigate other aspects of neuromotor control of the LM muscle to determine if there are impairments which could be addressed in an attempt to decrease the high prevalence of LBP in this population. (C) 2011 Elsevier Ltd. All rights reserved.