OBJECTIVE: Understanding of how female subjects learn to move accurately during a resisted weight-bearing task is limited. The purpose of this study was to examine the muscle activation patterns used by female subjects in learning a novel single-leg squat (SLS) task under visual and nonvisual conditions. DESIGN: Prospective training study. SETTING: University research setting. PARTICIPANTS: Ten healthy young female participants. INTERVENTION: Subjects tracked a sinusoidal target (knee displacement) during a resisted SLS exercise during the course of 4 days, under eyes open (EO) and eyes closed (EC) conditions with the use of a custom-designed weight-bearing exercise device. MAIN OUTCOME MEASUREMENT: The accuracy of performance in tracking the target and electromyographic activity (EMG) of 5 muscles around the knee were monitored. RESULTS: Subjects improved their accuracy of performance by day 2 (40% decrease in error) and retained the accuracy on day 4. Error during the EC condition was 3 times greater than EO condition. Quadriceps-to-hamstrings coactivation ratio increased with the improved accuracy from the learning. Absence of visual feedback was accompanied by a decrease in the quadriceps-to-hamstrings coactivation ratio for this task. CONCLUSION: The muscle synergistic activity around the knee changes as the accuracy of the task improves during a resisted weight-bearing task. This activation pattern represents a feed forward control plan that the central nervous system adopted to optimize accurate weight-bearing knee displacement. Rehabilitation specialists should consider manipulating the visual feedback and accuracy of performance when developing weight-bearing rehabilitation training protocols to improve neuromuscular control in female patients.
OBJECTIVE: Understanding of how female subjects learn to move accurately during a resisted weight-bearing task is limited. The purpose of this study was to examine the muscle activation patterns used by female subjects in learning a novel single-leg squat (SLS) task under visual and nonvisual conditions. DESIGN: Prospective training study. SETTING: University research setting. PARTICIPANTS: Ten healthy young female participants. INTERVENTION: Subjects tracked a sinusoidal target (knee displacement) during a resisted SLS exercise during the course of 4 days, under eyes open (EO) and eyes closed (EC) conditions with the use of a custom-designed weight-bearing exercise device. MAIN OUTCOME MEASUREMENT: The accuracy of performance in tracking the target and electromyographic activity (EMG) of 5 muscles around the knee were monitored. RESULTS: Subjects improved their accuracy of performance by day 2 (40% decrease in error) and retained the accuracy on day 4. Error during the EC condition was 3 times greater than EO condition. Quadriceps-to-hamstrings coactivation ratio increased with the improved accuracy from the learning. Absence of visual feedback was accompanied by a decrease in the quadriceps-to-hamstrings coactivation ratio for this task. CONCLUSION: The muscle synergistic activity around the knee changes as the accuracy of the task improves during a resisted weight-bearing task. This activation pattern represents a feed forward control plan that the central nervous system adopted to optimize accurate weight-bearing knee displacement. Rehabilitation specialists should consider manipulating the visual feedback and accuracy of performance when developing weight-bearing rehabilitation training protocols to improve neuromuscular control in female patients.
Authors: Robert A Scheidt; Michael A Conditt; Emanuele L Secco; Ferdinando A Mussa-Ivaldi Journal: J Neurophysiol Date: 2005-01-19 Impact factor: 2.714
Authors: Shih-Chiao Tseng; Keith R Cole; Michael A Shaffer; Michael A Petrie; Chu-Ling Yen; Richard K Shields Journal: Gait Posture Date: 2016-12-15 Impact factor: 2.840
Authors: Kingsley O Abode-Iyamah; Stephanus V Viljoen; Colleen L McHenry; Michael A Petrie; Kirsten E Stoner; Nader S Dahdaleh; Nicole M Grosland; Matthew A Howard; Richard K Shields Journal: Neurosurgery Date: 2016-11 Impact factor: 4.654