| 제목 |
The difference in gait adaptation pattern when the slope angle changes with or without prior notice |
| 소속 |
Yonsei University College of Medicine, Dept. and Research Institute of Rehabilitation Medicine1, Yonsei University College of Medicine, Department of Medicine2 |
| 저자 |
Dongho Park1*, Junyoung Lim2, Beomkey Yoo1, Dain Shim1, Joongon Choi1, Tae Young Choi1, Dong-wook Rha1† |
Aim
Human walking is known to be an efficient and rigorous activity orchestrated by feedback and feedforward control[1,2]. Feedback control adjusts locomotion to external conditions perceived by vestibular sensation and proprioception, whereas feedforward control prepares the adaptive gait pattern based on preprogrammed prediction.
To better understand the control of gait adaptation, we examined the difference of gait adaptation pattern during slope angle change whether it is informed in advance or not.
Subjects and methods
1. Subjects
The experimental group consisted of 19 young healthy adults.
2. Gait analysis
A total of 26 reflective markers are attached to the lower limb according to the HBM model used for 3D computer gait analysis, and kinematic data is captured by 10 infrared cameras at a sampling rate of 100 Hz while walking at a self-selected comfortable speed on the dynamic pitch treadmill (M-gait, Motek, Netherlands).
3. Experimental protocol
Subjects walked 40 steps at each slope at a self-selected walking speed, and the slope decreased by 2.5 degrees from 10 to -10 degrees. The average joint angles of walking at the first and last five steps after the slope change was compared to verify the hypothesis in this study that gait adaptation would take time after the slope change. In addition, to identify the difference in gait adaptation with or without feedforward strategy, verbal notification was provided to each subject just before slope change and compared to the results without prior notice.
Results
Without notification of the slope change, the first and last five steps showed statistically significant differences in the initial contact to the mid-stance phase and terminal swing phase at the hip, knee, and ankle joint even though they were walking on the same angle of the slope (p < 0.05) (Fig 1). On the contrary, gait kinematics did not show statistically significant change except for initial contact and terminal stance phase at the knee joint when the notification was given before slope change(p < 0.05) (Fig 2).
Conclusion
The difference in kinematics between the first five steps and the last five steps due to pedestrian adaptation was small when notices were provided before the slope angle was changed. These results might imply that notification before the slope angle change accelerated gait adaptation by reinforcing feedforward strategy.
References
1. Lam T, Anderschitz M, Dietz V. Contribution of Feedback and Feedforward Strategies to Locomotor Adaptations. J Neurophysiol. 2006;95:766-73.
2. Yen SC, Corkery MB, Donohoe A, Grogan M, Wu YN. Feedback and Feedforward Control During Walking in Individuals With Chronic Ankle Instability. J Orthop Sports Phys Ther. 2016;46:775-83.
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An example of joint kinematics without notification of the slope change from 10 degrees to -10 degrees. The black and red solid line indicates the first and last five steps of the slope, respectively. The gray area means statistically significant differences (p < 0.05).
An example of joint kinematics with notification of the slope change from 10 degrees to -10 degrees. The black and red solid line indicates the first and last five steps of the slope, respectively. The gray area means statistically significant differences (p < 0.05).
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