title: The effect of toe marker placement error on joint kinematics and muscle forces using OpenSim gait simulation.
abstract: Marker placement can be a significant source of error in biomechanical studies of human movement. The toe marker placement error is amplified by footwear since the toe marker placement on the shoe only relies on an approximation of underlying anatomical landmarks. Three total knee replacement subjects were recruited and three self-speed gait trials per subject were collected. The height variation between toe and heel markers of four types of footwear was evaluated from the results of joint kinematics and muscle forces using OpenSim. The reference condition was considered as the same vertical height of toe and heel markers. The results showed that the residual variances for joint kinematics had an approximately linear relationship with toe marker placement error for lower limb joints. Ankle dorsiflexion/plantarflexion is most sensitive to toe marker placement error. The influence of toe marker placement error is generally larger for hip flexion/extension and rotation than hip abduction/adduction and knee flexion/extension. The muscle forces responded to the residual variance of joint kinematics to various degrees based on the muscle function for specific joint kinematics. This study demonstrates the importance of evaluating marker error for joint kinematics and muscle forces when explaining relative clinical gait analysis and treatment intervention.
authors.affiliation: Department of Medical Imaging, Xuzhou Medical College, 209 Tongshan Road, Xuzhou, P.R. China.|Department of Mechanical Engineering, University of Utah, 50 S Central Campus Dr, Salt Lake City, UT, USA.
authors.forename: Hang
authors.initials: H
authors.lastname: Xu
authors.affiliation: Department of Mechanical Engineering, University of Utah, 50 S Central Campus Dr, Salt Lake City, UT, USA.
authors.forename: Andrew
authors.initials: A
authors.lastname: Merryweather
authors.affiliation: Department of Mechanical Engineering, University of Utah, 50 S Central Campus Dr, Salt Lake City, UT, USA.
authors.forename: Donald
authors.initials: D
authors.lastname: Bloswick
authors.affiliation: Department of Medical Imaging, Xuzhou Medical College, 209 Tongshan Road, Xuzhou, P.R. China.
authors.forename: Qi
authors.initials: Q
authors.lastname: Mao
authors.affiliation: Department of Medical Imaging, Xuzhou Medical College, 209 Tongshan Road, Xuzhou, P.R. China.
authors.forename: Tong
authors.initials: T
authors.lastname: Wang
mesh_terms: D000369:Aged, 80 and over; D059925:Anatomic Landmarks / Q000033:anatomy & histology / Q000473:pathology*; D003198:Computer Simulation; D005684:Gait / Q000502:physiology*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D021621:Imaging, Three-Dimensional / Q000379:methods*; D007596:Joints / Q000033:anatomy & histology / Q000502:physiology*; D007866:Leg / Q000502:physiology; D008297:Male; D008954:Models, Biological; D009119:Muscle Contraction / Q000502:physiology*; D018482:Muscle, Skeletal / Q000033:anatomy & histology / Q000502:physiology; D016059:Range of Motion, Articular; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
keywords: Toe marker placement; gait simulation; joint kinematics; muscle force