Reactive Recovery Strategies on Unexpected Stepping Down during Locomotion: Effects of Prior Knowledge and Experience |
Yeon-Joo Yu, Ki-Kwang Lee, Suk-Bum Kim |
Sangmyung University Kookmin University Seoul National University |
Correspondence:
Suk-Bum Kim, Email: bum3340@hanmail.net |
Received: 9 February 2014 • Accepted: 19 April 2014 |
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Abstract |
INTRODUCTION The purpose of the study was to determine the reactive recovery responses to maintain dynamic stability during unexpected stepping down, investigate response adaptation to repeated stepping down during locomotion. METHOD Eleven healthy men(Age: 22.0±0.9yrs, Height: 174.8±3.5cm, Weight: 67.6±5.4kg) participated in the study. In order to get kinematic data, ten cameras, markers, Visual 3D program were used. A force platform was used to get the Vertical Ground Reaction Force(VGRF) and activation of five muscles(Rectus Femoris, Biceps Femoris, Tibialis Anterior, Gastrocnemius, & Vastus Medialis) in both limbs were collected and analyzed with wireless EMG system. T-test was used to analyze the effects of knowledge of stepping down movement on lower extremity, VGRF and muscles activation. One-way repeated measures of ANOVA and Dunnett(Post-Hoc) were used to analyze the effects of repeated stepping down on lower extremity and trunk movement, VGRF and muscles activation. RESULT The knee flexion angle, the activation of Tibialis Anterior and Rectus Femoris in unperturbed leg, and VGRF in perturbed leg during unexpected stepping down movement were increased those than locomotion with expected stepping down. The increase of the hip rotation angle, decreases of knee and trunk angles were found in repeated stepping down movement. CONCLUSION Human body allows subsequent modification and adaptation to maintain dynamic stability with prior experience and knowledge with perturbation. |
Keywords:
Perturbation, Fall, Knowledge, Experience |
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