Sherrilyn Walters1,2, Ben Hoffman3,4,5, William MacAskill3,4, Michael A Johnson6, Graham R Sharpe6, Dean E Mills3,4. 1. Respiratory and Exercise Physiology Research Group, School of Health and Wellbeing, University of Southern Queensland, 11 Salisbury Road, Ipswich, QLD, 4305, Australia. sherrilyn.walters@usq.edu.au. 2. Centre for Health Research, Institute for Resilient Regions, University of Southern Queensland, Ipswich, QLD, Australia. sherrilyn.walters@usq.edu.au. 3. Respiratory and Exercise Physiology Research Group, School of Health and Wellbeing, University of Southern Queensland, 11 Salisbury Road, Ipswich, QLD, 4305, Australia. 4. Centre for Health Research, Institute for Resilient Regions, University of Southern Queensland, Ipswich, QLD, Australia. 5. School of Human Movement and Nutrition Sciences, The University of Queensland, Brisbane, QLD, Australia. 6. Exercise and Health Research Group, Sport, Health and Performance Enhancement (SHAPE) Research Centre, School of Science and Technology, Nottingham Trent University, Nottingham, Nottinghamshire, UK.
Abstract
PURPOSE: The mechanisms that explain the ability of trained martial arts practitioners to produce and resist greater forces than untrained individuals to aid combat performance are not fully understood. We investigated whether the greater ability of trained martial arts practitioners to produce and resist forces was associated with an enhanced control of respiratory pressures and neuromuscular activation of the respiratory, abdominal, and pelvic floor musculature. METHODS: Nine trained martial arts practitioners and nine untrained controls were instrumented with skin-surface electromyography (EMG) on the sternocleidomastoid, rectus abdominis, and the group formed by the transverse abdominal and internal oblique muscles (EMGtra/io). A multipair oesophageal EMG electrode catheter measured gastric (Pg), transdiaphragmatic (Pdi), and oesophageal (Pe) pressures and EMG of the crural diaphragm (EMGdi). Participants performed Standing Isometric Unilateral Chest Press (1) and Standing Posture Control (2) tasks. RESULTS: The trained group produced higher forces normalised to body mass2/3 (0.033 ± 0.01 vs. 0.025 ± 0.007 N/kg2/3 mean force in Task 1), lower Pe, and higher Pdi in both tasks. Additionally, they produced higher Pg (73 ± 42 vs. 49 ± 19 cmH2O mean Pg) and EMGtra/io in Task 1 and higher EMGdi in Task 2. The onset of Pg with respect to the onset of force production was earlier, and the relative contributions of Pg/Pe and Pdi/Pe were higher in the trained group in both tasks. CONCLUSION: Our findings demonstrate that trained martial arts practitioners utilised a greater contribution of abdominal and diaphragm musculature to chest wall recruitment and higher Pdi to produce and resist higher forces.
PURPOSE: The mechanisms that explain the ability of trained martial arts practitioners to produce and resist greater forces than untrained individuals to aid combat performance are not fully understood. We investigated whether the greater ability of trained martial arts practitioners to produce and resist forces was associated with an enhanced control of respiratory pressures and neuromuscular activation of the respiratory, abdominal, and pelvic floor musculature. METHODS: Nine trained martial arts practitioners and nine untrained controls were instrumented with skin-surface electromyography (EMG) on the sternocleidomastoid, rectus abdominis, and the group formed by the transverse abdominal and internal oblique muscles (EMGtra/io). A multipair oesophageal EMG electrode catheter measured gastric (Pg), transdiaphragmatic (Pdi), and oesophageal (Pe) pressures and EMG of the crural diaphragm (EMGdi). Participants performed Standing Isometric Unilateral Chest Press (1) and Standing Posture Control (2) tasks. RESULTS: The trained group produced higher forces normalised to body mass2/3 (0.033 ± 0.01 vs. 0.025 ± 0.007 N/kg2/3 mean force in Task 1), lower Pe, and higher Pdi in both tasks. Additionally, they produced higher Pg (73 ± 42 vs. 49 ± 19 cmH2O mean Pg) and EMGtra/io in Task 1 and higher EMGdi in Task 2. The onset of Pg with respect to the onset of force production was earlier, and the relative contributions of Pg/Pe and Pdi/Pe were higher in the trained group in both tasks. CONCLUSION: Our findings demonstrate that trained martial arts practitioners utilised a greater contribution of abdominal and diaphragm musculature to chest wall recruitment and higher Pdi to produce and resist higher forces.
Authors: Lisa Chasan-Taber; J Bianca Erickson; Jeanne W McBride; Philip C Nasca; Scott Chasan-Taber; Patty S Freedson Journal: Am J Epidemiol Date: 2002-02-01 Impact factor: 4.897