movement coordination was quantified as the initial and final humeral elevation angles at which scapular upward rotation and humeral elevation were linearly correlated. The initial and final “linear” elevation angles were averaged for each subject and are reported in both absolute (degrees) and relative
Margaret A. Finley, Elizabeth Euiler, Shivayogi V. Hiremath, and Joseph Sarver
Ben Langley, Nick Knight, and Stewart C. Morrison
with traditional injury paradigms, which link excessive eversion and tibial internal rotation to the development of running injuries. Excessive eversion has been assumed to result in increased tibial internal rotation, which would result in an in-phase movement coordination pattern rather than the
André Luiz Felix Rodacki, Neil Edward Fowler, and Simon Bennett
The aim of this study was to compare the kinematic pattern and the segmental movement co-ordination when the trunk segment was constrained in different positions during plyometric rebound jumps. Nine skilled volleyball players, experienced in plyometric training, were asked to perform a random series of maximal rebound jumps, using three different seat arrangements (90°, 135°, and 180°) in a pendulum swing device. From two-dimensional filming, performed in a right sagittal plane at 200 Hz, it was possible to calculate ankle, knee, and hip displacements; velocities; and muscle-tendon lengths. The subjects showed similar ankle and knee angles between experimental conditions. The hip joint angle differed significantly between conditions. Only the muscle-tendon lengths of the biarticular muscles spanning the knee/hip were affected by the seat arrangement variations. Significantly greater knee angular velocities were observed in the upright sitting posture (90°). The hip was consistently the first joint to extend. The ankle and knee joint reversals were not invariant, regardless of the seat arrangement. The movement co-ordination strategy did not differ across postural variations.
Rupal Mehta, Marco Cannella, Sharon M. Henry, Susan Smith, Simon Giszter, and Sheri P. Silfies
Trunk muscle timing impairment has been associated with nonspecific low back pain (NSLBP), but this finding has not been consistent. This study investigated trunk muscle timing in a subgroup of patients with NSLBP attributed to movement coordination impairment (MCI) and matched asymptomatic controls in response to a rapid arm-raising task. Twenty-one NSLBP subjects and 21 matched controls had arm motion and surface EMG data collected from seven bilateral trunk muscles. Muscle onset and offset relative to deltoid muscle activation and arm motion, duration of muscle burst and abdominal–extensor co-contraction time were derived. Trunk muscle onset and offset latencies, and burst and co-contraction durations were not different (p > .05) between groups. Patterns of trunk muscle activation and deactivation relative to arm motion were not different. Task performance was similar between groups. Trunk muscle timing does not appear to be an underlying impairment in the subgroup of NSLBP with MCI.
Lindsey Tulipani, Mark G. Boocock, Karen V. Lomond, Mahmoud El-Gohary, Duncan A. Reid, and Sharon M. Henry
incorrect diagnosis, treatment, and an unsuccessful rehabilitation strategy, particularly for multiplanar movement impairments. PTs could benefit from a clinic-friendly, cost effective method for accurately quantifying motion and movement coordination during functional tasks. A technology that is relatively
Charlotte Woods, Lesley Glover, and Julia Woodman
-related anxiety in musicians ( Jones & Glover, 2014 ; Klein, Bayard, & Wolf, 2014 ). Some of the observed benefit in these studies may be due to improved movement coordination, balance, postural tone, and proprioception after training in the Alexander technique ( Cacciatore, Gurfinkel, Horak, Cordo, & Ames, 2011
Jurjen Bosga, Ruud G. J. Meulenbroek, and Raymond H. Cuijpers
In this study, we investigate how two persons (dyads) coordinate their movements when performing cyclical motion patterns on a rocking board. In keeping with the Leading Joint Hypothesis (Dounskaia, 2005), the movement dynamics of the collaborating participants were expected to display features of a prime mover with low movement variability. Fourteen subject pairs performed the task in nine amplitude-frequency combinations that were presented in the form of a to-be-tracked stimulus on a computer display. Participants were asked to track the stimulus by jointly rocking the Board sideways while receiving continuous visual feedback of its rotations. Displacements of 28 IREDS that were attached to the rocking board, both ankles, knees, hips, shoulders and heads of both actors, were sampled at 75 Hz by means of a 3D-motion tracking system. From these data, we derived body-segment angular excursions as well as the continuous relative phase and time-lagged cross-correlations between relevant joint excursions. The results show that, at the intrapersonal level, knee rotations initially led all other joints in time while the antiphase coordination between the knees displayed relative low variability. At the interpersonal level, dyads adopted a leader-follower strategy with respect to the coordination demands of the task. We take that knee rotations create a dynamic foundation at both intra- and interpersonal levels involving subordination of individual action to joint performance thereby allowing for low-dimensional control of joint action in a high-dimensional, repetitive motor task.
Raoul Huys, Andreas Daffertshofer, and Peter J. Beek
To study the acquisition of perceptual-motor skills as an instance of dynamic pattern formation, we examined the evolution of postural sway and eye and head movements in relation to changes in performance, while 13 novices practiced 3-ball cascade juggling for 9 weeks. Ball trajectories, postural sway, and eye and head movements were recorded repeatedly. Performance improved exponentially, both in terms of the number of consecutive throws and the degree of frequency and phase locking between the ball trajectories. These aspects of performance evolved at different time scales, indicating the presence of a temporal hierarchy in learning. Postural sway, and eye and head movements were often 3:2 and sometimes 3:1 frequency locked to the ball trajectories. As a rule, the amplitudes of these oscillatory processes decreased exponentially at rates similar to that of the increase in the degree of phase locking between the balls. In contrast, the coordination between these oscillatory processes evolved exponentially at different time scales, apart from some erratic evolutions. Collectively, these findings indicate that skill acquisition in the perceptual-motor domain involves multiple time scales and multiform dynamics, both in terms of the development of the goal behavior itself and the evolution of the processes subserving this goal behavior.
Julia Freedman Silvernail, Richard E.A. van Emmerik, Katherine Boyer, Michael A. Busa, and Joseph Hamill
as a surrogate measure for the underlying organization of the movement. Measures of movement coordination can provide information on the health of the motor system and may also provide insight to the mechanism for overuse injury as altered magnitude and timing of segment motions can change the strain