Kojima S1, Kawaji H2
1Health Sciences University of Hokkaido, Physical Therapy, Ishikari-Tobetsu, Japan, 2Graduate School of Rehabilitation Sciences, Health Sciences University of Hokkaido, Ishikari-Tobetsu, Japan
Background: Abnormal kinematic coupling between ankle-foot and knee joints is known as a potential mechanism for musculoskeletal injuries of the knee in sports. However, it has not been well understood how this kinematic coupling occurs during sports-related tasks in healthy subjects.
Purpose: The purpose of this study was to investigate the relationship between ankle-foot and knee kinematics during a jump-landing task in healthy subjects.
Methods: Eighteen healthy adults (nine men, nine women; mean ± SD age, 21.4 ± 0.5 years; heights, 1.6 ± 0.1m; body mass, 58.6 ± 9.5 kg) participated in this study. Three dimensional motion data were collected using an 8-camera motion analysis system (Motion Analysis Corp., USA) with a sampling frequency of 100 Hz. Ground reaction force were sampled at 1,000 Hz using two force plates (AMTI, USA) embedded in the floor. Reflective markers were attached to each subject's pelvis and landmarks on the thigh, shank, and foot segments of the right limb. The subjects were asked to perform a drop jump-landing task. They were instructed to jump off a 30-cm high box horizontally and land on the force plates with both feet. After some practice trials, five successful trials were recorded for each subject. Three-dimensional angles of the ankle-foot and knee joints were calculated using a multi-segment foot model (Rizzoli foot model) and a lower limb model (Helen Hayes model), respectively. Angular displacements of the ankle-foot and knee joints were identified during loading phase of landing, which was defined as the time interval between initial ground contact and peak knee flexion. The initial ground contact was detected as the instant at which the vertical ground reaction force exceeded 10 N. Pearson bivariate correlation analyses was conducted to evaluate the relationship between ankle-foot and knee kinematics. Significance levels were set to P .05.
Results: A significant correlation was shown between knee external/internal rotation and ankle-foot dorsiflexion/plantarflexion (r = 0.521, P = .0.27) or adduction/abduction (r = 0.502, P = .034).
Conclusion(s): The results of this study suggest that the ankle-foot sagittal and transverse plane motions affect knee transverse plane motion during the jump-landing task in healthy subjects.
Implications: This study provides basic information for understanding mechanisms for musculoskeletal injuries which may be caused by abnormal kinematic coupling between ankle-foot and knee joints.
Keywords: Movement analysis, kinematic coupling, jump-landing task
Funding acknowledgements: Unfunded.
Purpose: The purpose of this study was to investigate the relationship between ankle-foot and knee kinematics during a jump-landing task in healthy subjects.
Methods: Eighteen healthy adults (nine men, nine women; mean ± SD age, 21.4 ± 0.5 years; heights, 1.6 ± 0.1m; body mass, 58.6 ± 9.5 kg) participated in this study. Three dimensional motion data were collected using an 8-camera motion analysis system (Motion Analysis Corp., USA) with a sampling frequency of 100 Hz. Ground reaction force were sampled at 1,000 Hz using two force plates (AMTI, USA) embedded in the floor. Reflective markers were attached to each subject's pelvis and landmarks on the thigh, shank, and foot segments of the right limb. The subjects were asked to perform a drop jump-landing task. They were instructed to jump off a 30-cm high box horizontally and land on the force plates with both feet. After some practice trials, five successful trials were recorded for each subject. Three-dimensional angles of the ankle-foot and knee joints were calculated using a multi-segment foot model (Rizzoli foot model) and a lower limb model (Helen Hayes model), respectively. Angular displacements of the ankle-foot and knee joints were identified during loading phase of landing, which was defined as the time interval between initial ground contact and peak knee flexion. The initial ground contact was detected as the instant at which the vertical ground reaction force exceeded 10 N. Pearson bivariate correlation analyses was conducted to evaluate the relationship between ankle-foot and knee kinematics. Significance levels were set to P .05.
Results: A significant correlation was shown between knee external/internal rotation and ankle-foot dorsiflexion/plantarflexion (r = 0.521, P = .0.27) or adduction/abduction (r = 0.502, P = .034).
Conclusion(s): The results of this study suggest that the ankle-foot sagittal and transverse plane motions affect knee transverse plane motion during the jump-landing task in healthy subjects.
Implications: This study provides basic information for understanding mechanisms for musculoskeletal injuries which may be caused by abnormal kinematic coupling between ankle-foot and knee joints.
Keywords: Movement analysis, kinematic coupling, jump-landing task
Funding acknowledgements: Unfunded.
Topic: Human movement analysis; Musculoskeletal: lower limb; Orthopaedics
Ethics approval required: Yes
Institution: Health Sciences university of Hokkaido
Ethics committee: Health Sciences university of Hokkaido
Ethics number: 18R081074
All authors, affiliations and abstracts have been published as submitted.
