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Kimoto M1,2, Okada K1, Mitobe K3, Sakamoto H2, Kawanobe U2, Horioka W2, Wakasa M1, Saitou A1
1Akita University Graduate School of Medicine, Doctorial Course in Health Sciences, Akita, Japan, 2Akita Prefectural Center on Development and Disability, Department of Rehabilitation, Akita, Japan, 3Akita University Graduate School of Engineering and Resource Science, Department of Mathematical Science and Electrical-Electronic-Computer Engineering, Akita, Japan
Background: Children with cerebral palsy (CP) face difficulty in stabilizing the body on sudden alteration of momentum during gait termination; however, the mechanism for the same has not been reported.
Purpose: This study aimed to compare the kinematic and kinetic characteristics during gait termination between children with CP and adolescents with typical development (TD).
Methods: Participants comprised 12 children with spastic diplegic CP (7 boys, 5 girls; mean age, 11 y 2 mo; standard deviation, 2 y 10 mo; gross motor function classification level: I, n=9; II, n=3) and 9 male adolescents with typical development (mean age, 19 y 7 mo; standard deviation, 0 y 5 mo).
A kinematic and kinetic analysis of gait termination was performed using an eight-camera reflective marker system to capture motion (MX-T10, Vicon motion system) with five force plates (AccuGait, AMTI).
An 80-inch screen was located at the end of the walkway to project a stopping signal. We constructed a task presentation system in which the screen color would change immediately when a subject stepped on a force plate. Subjects performed trials at their preferred speed. They were not told beforehand which force plate to stop on. They were instructed to “freeze” as soon as they saw the screen color change from green to red.
We compared the stopping-time after the appearance of stopping signal, joint angle, moment, and power in the lower leg, center of gravity (COG) and center of pressure (COP) displacement in the mediolateral (ML) and anteroposterior (AP) direction, and maximum vector angle of the ground reaction force (GRF) between children with CP and adolescents with TD.
Results: The stopping-time was significantly longer in children with CP (1.24±0.18 vs. 0.95±0.29 s; p 0.001). The joint moment and power showed no significant difference between children with CP and adolescents with TD. However, children with CP presented significantly higher values of maximum knee flexion angle (47.2±13.8 vs. 34.9±6.7°; p=0.015), lower values of maximum plantarflexion angle (4.5±13.4 vs. 17.9±5.6°; p=0.007), and lower values of maximum vector angle of GRF (18.9±4.3 vs. 24.1±4.0°; p=0.002) than adolescents with TD. The displacement of COG and COP were significantly greater than that in adolescents, 1.4-1.6 times (p=0.001) in the AP direction and 2.2-4.6 times (p 0.001) in the ML direction.
Conclusion(s): Gait termination is required for the initiation of the application of braking force to reduce the horizontal velocity of the COG. More vertical vectors of GRF attribute to knee hyper-flexion and greater displacement of COG and COP in the ML direction during stopping motion in children with CP. We ascribed prolonged stopping-time to more vertical braking force.
Implications: The findings of this study suggest that focusing on the direction of braking force is more important than focusing on the magnitude of the joint moment due to increased walking ability.
Keywords: cerebral palsy, gait termination, walk
Funding acknowledgements: This work was supported by JSPS KAKENHI Grant Number JP18K17708.
Purpose: This study aimed to compare the kinematic and kinetic characteristics during gait termination between children with CP and adolescents with typical development (TD).
Methods: Participants comprised 12 children with spastic diplegic CP (7 boys, 5 girls; mean age, 11 y 2 mo; standard deviation, 2 y 10 mo; gross motor function classification level: I, n=9; II, n=3) and 9 male adolescents with typical development (mean age, 19 y 7 mo; standard deviation, 0 y 5 mo).
A kinematic and kinetic analysis of gait termination was performed using an eight-camera reflective marker system to capture motion (MX-T10, Vicon motion system) with five force plates (AccuGait, AMTI).
An 80-inch screen was located at the end of the walkway to project a stopping signal. We constructed a task presentation system in which the screen color would change immediately when a subject stepped on a force plate. Subjects performed trials at their preferred speed. They were not told beforehand which force plate to stop on. They were instructed to “freeze” as soon as they saw the screen color change from green to red.
We compared the stopping-time after the appearance of stopping signal, joint angle, moment, and power in the lower leg, center of gravity (COG) and center of pressure (COP) displacement in the mediolateral (ML) and anteroposterior (AP) direction, and maximum vector angle of the ground reaction force (GRF) between children with CP and adolescents with TD.
Results: The stopping-time was significantly longer in children with CP (1.24±0.18 vs. 0.95±0.29 s; p 0.001). The joint moment and power showed no significant difference between children with CP and adolescents with TD. However, children with CP presented significantly higher values of maximum knee flexion angle (47.2±13.8 vs. 34.9±6.7°; p=0.015), lower values of maximum plantarflexion angle (4.5±13.4 vs. 17.9±5.6°; p=0.007), and lower values of maximum vector angle of GRF (18.9±4.3 vs. 24.1±4.0°; p=0.002) than adolescents with TD. The displacement of COG and COP were significantly greater than that in adolescents, 1.4-1.6 times (p=0.001) in the AP direction and 2.2-4.6 times (p 0.001) in the ML direction.
Conclusion(s): Gait termination is required for the initiation of the application of braking force to reduce the horizontal velocity of the COG. More vertical vectors of GRF attribute to knee hyper-flexion and greater displacement of COG and COP in the ML direction during stopping motion in children with CP. We ascribed prolonged stopping-time to more vertical braking force.
Implications: The findings of this study suggest that focusing on the direction of braking force is more important than focusing on the magnitude of the joint moment due to increased walking ability.
Keywords: cerebral palsy, gait termination, walk
Funding acknowledgements: This work was supported by JSPS KAKENHI Grant Number JP18K17708.
Topic: Paediatrics: cerebral palsy; Human movement analysis
Ethics approval required: Yes
Institution: Akita university
Ethics committee: The Medical Ethics Committee
Ethics number: 2039
All authors, affiliations and abstracts have been published as submitted.
