Michael C Rumpf1, John B Cronin2, Ikhwan N Mohamad3, Sharil Mohamad4, Jon L Oliver5, Michael G Hughes6. 1. Sport Performance Research Institute New Zealand, AUT University, 90 Akoranga Drive North Shore, Auckland, New Zealand; New Zealand Football, Lion Foundation House, Albany, Auckland, New Zealand. Electronic address: rumpf.michael@web.de. 2. Sport Performance Research Institute New Zealand, AUT University, 90 Akoranga Drive North Shore, Auckland, New Zealand; School of Exercise, Biomedical and Health Sciences, Edith Cowan University, 270 Joondalup Drive, Joondalup, Western Australia 6027, Australia. Electronic address: jcronin@aut.ac.nz. 3. Sultan Idris Education University, 35900 Tanjong Malim, Pera Perak, Malaysia. Electronic address: nurmupsi@gmail.com. 4. National Sport Institute Malaysia, Bukit Jalil, Kuala Lumpur 50714, Malaysia. Electronic address: sharilmohd@gmail.com. 5. Cardiff School of Sport, Western Avenue, Cardiff Metropolitan University, Cardiff, Wales, UK. Electronic address: joliver@cardiffmet.ac.uk. 6. Cardiff School of Sport, Western Avenue, Cardiff Metropolitan University, Cardiff, Wales, UK. Electronic address: mghughes@cardiffmet.ac.uk.
Abstract
OBJECTIVES: A possible injury risk factor is limb asymmetry, which may differ across maturation given the adult growth spurt. The aim of this study is to quantify the magnitude of asymmetry in a number of kinetic variables during a running task in male youth of different maturity status. DESIGN: Quantitative observational laboratory study. SETTING: Sports performance laboratory. PARTICIPANTS: Non-injured youth athletes in pre-, mid-, and post-pubescent status. MAIN OUTCOME MEASURES: Inter-limb leg asymmetries whilst sprinting on a non-motorized treadmill. Percent asymmetry was defined as: (Left leg - right leg)/right leg*100 = %asymmetry. RESULTS: Horizontal force presented limb asymmetries of 15.4, 14.8 and 14.7% for the pre-, mid- and post-PHV group respectively. Values for vertical force were higher (18.1, 20.2 and 20.8% respectively). Power asymmetries were 14.9, 15.8, and 15.5% respectively and work asymmetries were significant higher in pre-PHV participants (26.4%) compared to mid- (14.7%) and post-PHV (17.3%) participants. CONCLUSIONS: As the population in this study was characterized as non-injured, asymmetries of 15-20% appeared typical during a running task in developmental athletes.
OBJECTIVES: A possible injury risk factor is limb asymmetry, which may differ across maturation given the adult growth spurt. The aim of this study is to quantify the magnitude of asymmetry in a number of kinetic variables during a running task in male youth of different maturity status. DESIGN: Quantitative observational laboratory study. SETTING: Sports performance laboratory. PARTICIPANTS: Non-injured youth athletes in pre-, mid-, and post-pubescent status. MAIN OUTCOME MEASURES: Inter-limb leg asymmetries whilst sprinting on a non-motorized treadmill. Percent asymmetry was defined as: (Left leg - right leg)/right leg*100 = %asymmetry. RESULTS: Horizontal force presented limb asymmetries of 15.4, 14.8 and 14.7% for the pre-, mid- and post-PHV group respectively. Values for vertical force were higher (18.1, 20.2 and 20.8% respectively). Power asymmetries were 14.9, 15.8, and 15.5% respectively and work asymmetries were significant higher in pre-PHV participants (26.4%) compared to mid- (14.7%) and post-PHV (17.3%) participants. CONCLUSIONS: As the population in this study was characterized as non-injured, asymmetries of 15-20% appeared typical during a running task in developmental athletes.