The nature of intra- and interlimb (bimanual) coordination was examined in ten boys with (M = 10.5 years, SD = 1.0) and without DCD (M = 10.8 years, SD = .9) in a two-handed catching task. Children with developmental coordination disorder (DCD) caught significantly fewer balls (MDCD = 56%, SD = 17.6 vs. MnoDCD = 93%, SD = 7.5), and both groups solved the “degrees of freedom problem” differently at intralimb level of coordination. Typically developing children coupled and decoupled the respective spatial relations, whereas the majority of children with DCD segmented their actions. At interlimb level, both groups exhibited a comparable degree of spatial symmetry. However, individual profiles also showed that children with varying degrees of movement issues exhibited movement patterns that were qualitatively and functionally diverse. Overall, in the context of previous research on interlimb coordination it appears that spatial, in addition to temporal organization, may be jeopardized in at least some children with DCD.
Eryk P. Przysucha and Brian K.V. Maraj
Mark L. Latash, John P. Scholz, and Gregor Schöner
Driven by recent empirical studies, we offer a new understanding of the degrees of freedom problem, and propose a refined concept of synergy as a neural organization that ensures a one-to-many mapping of variables providing for both stability of important performance variables and flexibility of motor patterns to deal with possible perturbations and/or secondary tasks. Empirical evidence is reviewed, including a discussion of the operationalization of stability/flexibility through the method of the uncontrolled manifold. We show how this concept establishes links between the various accounts for how movement is organized in redundant effector systems.
Liesbeth I.N. Mazyn, Gilles Montagne, Geert J.P. Savelsbergh, and Matthieu Lenoir
In the present study, the limits of human catching behavior were challenged to investigate quantitative and qualitative adaptations of the catching movement when performing under varying ball speeds, implying minor as well as severe temporal constraints. Nine male participants caught balls approaching at speeds ranging from 8.5 to 19.7 m/s with their preferred hand. Although a decrease in catching performance was undeniable, several quantitative adaptations provided the catcher with extra time and allowed to compensate the decrease in spatial accuracy with increasing speed. More importantly, changes in the coordination between hand, elbow, and shoulder emerged with increasing movement velocity. More demanding temporal constraints lead to a shift from relatively independent activity of each joint towards a mode in which several joints act as one unit. This reorganization of the coordination pattern of the catch is discussed in the context of Bernstein’s degrees of freedom problem.
Emmanuel Jacobs, Nathalie Roussel, Ine Van Caekenberghe, Edith Cassiers, Luc Van den Dries, Jonas Rutgeerts, Jan Gielen, and Ann Hallemans
This cross-sectional study aimed at developing a biomechanical method to objectify voluntary and unpredictable movements, using an automated three-dimensional motion capture system and surface electromyography. Fourteen experienced theater performers were tested while executing the old man exercise, wherein they have to walk like an old man, building up a sustained high intensive muscular activity and tremor. Less experienced performed showed a different kinematics of movement, a slower speed of progression and more variable EMG signals at higher intensity. Female performers also differed from males in movement kinematics and muscular activity. The number of the trial only influenced the speed of progression. The performers showed results which could be well placed within the stages of learning and the degrees of freedom problem.
Robert W. Christina
By 1967, motor control and learning researchers had adopted an information processing (IP) approach. Central to that research was understanding how movement information was processed, coded, stored, and represented in memory. It also was centered on understanding motor control and learning in terms of Fitts’ law, closed-loop and schema theories, motor programs, contextual interference, modeling, mental practice, attentional focus, and how practice and augmented feedback could be organized to optimize learning. Our constraints-based research from the 1980s into the 2000s searched for principles of “self-organization”, and answers to the degrees-of-freedom problem, that is, how the human motor system with so many independent parts could be controlled without the need for an executive decision maker as proposed by the IP approach. By 2007 we were thinking about where the IP and constraints-based views were divergent and complementary, and whether neural-based models could bring together the behavior and biological mechanisms underlying the processes of motor control and learning.
Karl M. Newell
– Efficacy of clinical trials in rehabilitation; Jane Kent – Muscle function and energetics; Mark Latash – The degrees of freedom problem in motor control; Tom Stoffregen – Perceptual information for motor control); and Movement forms, function and skill in context (Blandine Bril – Culture and motor skill
Cheryl M. Glazebrook
). Integrating Optimal and Motor Control The question of how humans can perform skilled actions with many movement possibilities, in other words the degrees of freedom problem, is central for researchers from a range of fields interested in motor control and learning ( Latash et al., 2010 ; Schmidt et al., 2018
Bruno G. Straiotto, David P. Cook, Darren C. James, and P. John Seeley
proximal to distal sequence. Later in the learning process, once the performer has achieved mastery of redundant degrees of freedom over the skill, more efficient solutions to the degrees of freedom problem would be used. 31 Specifically, joints, segments, muscles, and motor units would be turned into
Cameron T. Gibbons, Polemnia G. Amazeen, and Aaron D. Likens
; Latash & Turvey, 1996 ). Bernstein’s degrees of freedom problem refers to the impossibility of specifying positional and kinematic information for the control of each of those degrees of freedom in the service of a particular movement goal. Bernstein’s solution was to reduce the degrees of freedom by the
Jill Whitall, Nadja Schott, Leah E. Robinson, Farid Bardid, and Jane E. Clark
addressing the degrees of freedom problem, and also the problem of context-conditioned variability ( Bernstein, 1967 ; Turvey, Fitch, & Tuller, 1982 ). The latter refers to internal and external sources of constraints that alter the context of a behavior such that the same neural input will produce