exercise, and well-being, positions the study of human movement as a key player to advance a social justice agenda in the field of allied health. Supporting the Black Lives Matter movement’s struggle to acknowledge many marginalized voices ( Chatelain & Asoka, 2015 ; Collins, 2019 ; Singer, 2016 ), and
Mara Simon, Jihyeon Lee, Megen Evans, Sheldon Sucre, and Laura Azzarito
Richard E.A. Van Emmerik, Michael T. Rosenstein, William J. McDermott, and Joseph Hamill
Nonlinear dynamics and dynamical systems approaches and methodologies are increasingly being implemented in biomechanics and human movement research. Based on the early insights of Nicolai Bernstein (1967), a significantly different outlook on the movement control “problem” over the last few decades has emerged. From a focus on relatively simple movements has arisen a research focus with the primary goal to study movement in context, allowing the complexity of patterns to emerge. The approach taken is that the control of multiple degrees-of-freedom systems is not necessarily more difficult or complex than that of systems only comprising a few degrees of freedom. Complex patterns and dynamics might not require complex control structures. In this paper we present a tutorial overview of the mathematical underpinnings of nonlinear dynamics and some of its basic analysis tools. This should provide the reader with a basic level of understanding about the mathematical principles and concepts underlying pattern stability and change. This will be followed by an overview of dynamical systems approaches in the study of human movement. Finally, we discuss recent progress in the application of nonlinear dynamical techniques to the study of human locomotion, with particular focus on relative phase techniques for the assessment of coordination.
Daniel P. Ferris and Bryan R. Schlink
Robotic exoskeletons and bionic prostheses have moved from science fiction to science reality in the last decade. These robotic devices for assisting human movement are now technically feasible given recent advancements in robotic actuators, sensors, and computer processors. However, despite the ability to build robotic hardware that is wearable by humans, we still do not have optimal controllers to allow humans to move with coordination and grace in synergy with the robotic devices. We consider the history of robotic exoskeletons and bionic limb prostheses to provide a better assessment of the roadblocks that have been overcome and to gauge the roadblocks that still remain. There is a strong need for kinesiologists to work with engineers to better assess the performance of robotic movement assistance devices. In addition, the identification of new performance metrics that can objectively assess multiple dimensions of human performance with robotic exoskeletons and bionic prostheses would aid in moving the field forward. We discuss potential control approaches for these robotic devices, with a preference for incorporating feedforward neural signals from human users to provide a wider repertoire of discrete and adaptive rhythmic movements.
Julie Vaughan-Graham, Kara Patterson, Karl Zabjek, and Cheryl A. Cott
Human movement is a complex phenomenon presenting considerable challenges regarding how it is systematically and consistently described and investigated both from clinical and research perspectives ( Harbourne & Stergiou, 2009 ; Latash, Levin, Scholz, & Schöner, 2010 ; Levin, Liebermann, Parmet
Paul G. Taylor, Michael Small, Kwee-Yum Lee, Raul Landeo, Damien M. O’Meara, and Emma L. Millett
Entropy is an effective tool for investigation of human movement variability. However, before applying entropy, it can be beneficial to employ analyses to confirm that observed data are not solely the result of stochastic processes. This can be achieved by contrasting observed data with that produced using surrogate methods. Unlike continuous movement, no appropriate method has been applied to discrete human movement. This article proposes a novel surrogate method for discrete movement data, outlining the processes for determining its critical values. The proposed technique reliably generated surrogates for discrete joint angle time series, destroying fine-scale dynamics of the observed signal, while maintaining macro structural characteristics. Comparison of entropy estimates indicated observed signals had greater regularity than surrogates and were not only the result of stochastic but also deterministic processes. The proposed surrogate method is both a valid and reliable technique to investigate determinism in other discrete human movement time series.
Scott Kretchmar and Mark L. Latash
quickly and pervasively other rules and constraints beyond the laws of classical physics (and reaching all the way up to ethical ideals and principles) affect human movement behavior. The purpose is not to address and solve specific questions about ethics or motor control but, rather, to find a framework
Fabien Cignetti, Sébastien Caudron, Marianne Vaugoyeau, and Christine Assaiante
There is evidence that adolescence is a critical period in development, most likely involving important modifications of the body schema and of the sensorimotor representations. The present study addressed this issue, by investigating the differences between adolescents and adults regarding the integration of proprioceptive information at both perceptual and postural levels and the visual recognition of human movement. Proprioceptive integration was examined using muscle-tendon vibration that evoked either a postural response or an illusory sensation of movement. The ability to recognize human movement was investigated from a paradigm where the participants had to discern between human movements performed with and without gravity. The study produced three main findings. First, the adolescents had larger postural responses to tendon vibrations than the adults, with visual information enabling them to reduce this exaggerated postural reaction. Second, the adolescents had a greater illusory perception of movement compared with the adults. Third, the adolescents had the same perceptual ability as adults in the human movement perception task. In conclusion, we were able to highlight notable differences between adolescents and young adults, which confirms the late maturation of multisensory integration for postural control and the privileged visual contribution to postural control.
Landon B. Lempke, Jeonghoon Oh, Rachel S. Johnson, Julianne D. Schmidt, and Robert C. Lynall
human movement. Dual-task differences among musculoskeletal-injured and concussed individuals on gait and balance tasks after initial injury are concerning. However, it is unknown if these dual-task deficits are present, or even amplified, under more sport-like, functional movements. Growing research
Andy Roosen, Matthew T.G. Pain, and Mickaël Begon
Much research is ongoing into improving the accuracy of functional algorithms to determine joint centers (JC), but there has been limited testing using human movement data. This paper is in three parts: Part 1, errors in determining JCs from real human movement data using the SCoRE method; Part 2, variability of marker combinations during a punch; Part 3, variability in the JC due to reconstruction. Results indicate determining the JC of the shoulder or elbow with a triad of markers per segment with an accuracy greater than 20 mm is unlikely. Part 2 suggests conducting a pilot study with abundant markers to obtain triads, which are most stable due to differences of 300–400% in variability between triads. Variability due to the choice of reference frame for reconstruction during the punch ranged from 2.5 to 13.8 mm for the shoulder and 1.5 to 21.1 mm for the elbow. It would appear more pertinent to enhance the practical methods in situ than to further improve theoretical accuracy of functional methods.
Mark L. Latash
–Petrov–Kharlamov. Kharlamov was famous for his agility, and Petrov was very hard to move away from the spot in front of the goal, thus showing high stability. The best known example of effector specialization in human movement science is, arguably, hand dominance. Over hundreds of years, common wisdom viewed the two hands as