Predictive modelling of human walking over a complete gait cycle

Ren, Lei; Jones, Richard; Howard, David

doi:10.1016/j.jbiomech.2006.07.017

Cited by 150 publications

(136 citation statements)

References 19 publications

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“…constant success can be achieved with a number of techniques) and so the preferred technique might well be to adopt a minimal effort or energy strategy (e.g. walking, Ren, Jones and Howard, 2007). However, if the task is more complex, like the upstart (where the gymnast must remain within strength and anatomical limits, must arrive in a predetermined orientation and configuration and where the gymnast must perform correct actions at a correct time despite the presence of noise in the motor system) it might be that the solution space is so small that it effectively defines the technique.…”

Section: Discussionmentioning

confidence: 99%

Investigating optimal technique in a noisy environment: Application to the upstart on uneven bars

Hiley

Yeadon

2013

Human Movement Science

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Additional Information:• NOTICE: this is the author's version of a work that was accepted for publication in Human Movement Science.Changes ABSTRACTThe upstart is a fundamental skill in gymnastics which is used to transfer a gymnast from a swing beneath the bar to a position above the bar. The aim of this study was to optimise the technique in the upstart on the uneven bars in order to determine the underlying control strategy used by gymnasts. A previous attempt based on minimising joint torque had failed to find a satisfactory solution without forcing the joint angle histories to pass through a "via-point" (Yamasaki et al., 2010). Using a computer simulation model of a gymnast and bar, the technique (joint angle histories) used in the upstart was optimised under three different criteria: minimising joint torque, minimising joint torque change and maximising success in the presence of movement variability. The third optimisation introduced "noise" into the joint angle time histories based on measurements of kinematic variability. All three optimisations were started from the technique used by a gymnast competing in an Olympic Games uneven bars final. Root mean squared (RMS) differences between the recorded and optimal joint angle time histories were computed. The two optimisations based on minimising joint torque diverged from the gymnast's technique. However, the technique based on maximising the number of successful performances in a noisy environment remained close to the gymnast's technique. It is concluded that the underlying strategy used in the upstart is not based on minimisation of joint torque; rather, it is based on ensuring success in the task despite the inherent variability in technique. Gymnasts develop techniques that are able to cope with the level of kinematic variability present in their movements.

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Section: Discussionmentioning

confidence: 99%

Investigating optimal technique in a noisy environment: Application to the upstart on uneven bars

Hiley

Yeadon

2013

Human Movement Science

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“…Minimising effort (joint torques) or energy has been used to describe the underlying technique of everyday activities such as walking (Ren, Jones & Howard, 2007;Anderson & Pandy, 2001). When optimising sporting movements minimising joint torque has also been used with varying degrees of success (Hiley & Yeadon, 2012;Koschorreck & Mombaur, 2012;Yamasaki, Gotoh & Xin, 2010).…”

Section: Introductionmentioning

confidence: 99%

Investigating optimal technique in the presence of motor system noise: application to the double layout somersault dismount on high bar

Hiley

Yeadon

2015

Journal of Sports Sciences

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Minimising joint torque is often used as an optimisation criterion when investigating human movement. Alternatively, an aspect of performance may be chosen to be maximised when investigating sporting movements. The aim of the study was to optimise the technique in the backward giant circle prior to a double layout somersault dismount from the high bar using various criteria to determine which best characterised the technique adopted by a gymnast. Ten recorded gymnast trials were used to determine bar release parameters and the level of noise in the gymnast's movements. A computer simulation model of a gymnast and bar was used to optimise giant circle technique under three criteria: minimising joint torques, maximising the release window and maximising success in the presence of motor system noise. Local and global optimisations of technique were performed using the three criteria starting from the average technique of the 10 recorded trials. All global optimum solutions diverged from the gymnast's technique. The local optimum for maximising success in the presence of noise had a success rate comparable with the global optimum (98% vs. 100%, respectively). It is concluded that the gymnast's technique is characterised by maximising success despite operating with motor system noise.

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“…Simulation studies on gait have used models such as the triple rocker (Perry, 1992), polynomial fits (Ju and Mansour, 1988;Ren et al, 2007) and COP-based fits (Koopman et al, 1995;Srinivasan et al, 2008). McGeer (1990) used circular arcs for the plantar surface of the foot in passive dynamic walkers, and Vanderpool et al (2008) found that rolling feet are energetically efficient and can account for the loss of ankle motion.…”

Section: S Mohan Varma and S Sujatha: Segmental Contributions Tomentioning

confidence: 99%

“…Unlike other optimization-based inverse models (Koopman et al, 1995;Ren et al, 2007) in which optimization is used in parallel with the inverse model to predict the kinematics, kinetics or both, here optimization is used only to correct any errors in data that cause violation of the kinematic constraints. The effects of using the FROS and AFROS ) models on the GRF computations are studied.…”

Section: S Mohan Varma and S Sujatha: Segmental Contributions Tomentioning

confidence: 99%

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Segmental contributions to the ground reaction force in the single support phase of gait

Varma

Sujatha

2014

Mech. Sci.

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Abstract. An inverse dynamics model for the single support (SS) phase of gait is developed to study segmental contributions to the ground reaction force (GRF). With segmental orientations as the generalized degrees of freedom (DOF), the acceleration of the body's center-of-mass is expressed analytically as the summation of the weighted kinematics of individual segments. The weighting functions are constants that are functions of the segment masses and center-of-mass distances. Using kinematic and anthropometric data from literature as inputs, and using the roll-over-shape (ROS) to model the foot-ground interaction, GRF obtained from the inverse model are compared with measured GRF data from literature. The choice of the generalized coordinates and mathematical form of the model provides a means to weigh individual segment contributions, simplify models and choose more kinetically accurate inverse dynamics models. For the kinematic data used, an anthropomorphic model that includes the frontal plane rotation of the pelvis in addition to the sagittal DOF of the thigh and shank most accurately captures the vertical component of the GRF in the SS phase of walking. Of the two ROS used, the ankle-foot roll-over shape provides a better approximation of the kinetics in the SS phase. The method presented here can be used with additional experimental studies to confirm these results.

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Predictive modelling of human walking over a complete gait cycle

Cited by 150 publications

References 19 publications

Investigating optimal technique in a noisy environment: Application to the upstart on uneven bars

Investigating optimal technique in a noisy environment: Application to the upstart on uneven bars

Investigating optimal technique in the presence of motor system noise: application to the double layout somersault dismount on high bar

Segmental contributions to the ground reaction force in the single support phase of gait

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