Quantifying Segmental Contributions to Center-of-Mass Motion During Dynamic Continuous Support Surface Perturbations Using Simplified Estimation Models

2020 ◽  
Vol 36 (4) ◽  
pp. 198-208
Author(s):  
Alison Schinkel-Ivy ◽  
Vicki Komisar ◽  
Carolyn A. Duncan
Keyword(s):  
Balance Control ◽  
Center Of Mass ◽  
Three Dimensional ◽  
The Body ◽  
Whole Body ◽  
Mass Motion ◽  
Support Surface ◽  
Body Segments ◽  
Body Model ◽  
Full Body

Investigating balance reactions following continuous, multidirectional, support surface perturbations is essential for improving our understanding of balance control in moving environments. Segmental motions are often incorporated into rapid balance reactions following external perturbations to balance, although the effects of these motions during complex, continuous perturbations have not been assessed. This study aimed to quantify the contributions of body segments (ie, trunk, head, upper extremity, and lower extremity) to the control of center-of-mass (COM) movement during continuous, multidirectional, support surface perturbations. Three-dimensional, whole-body kinematics were captured while 10 participants experienced 5 minutes of perturbations. Anteroposterior, mediolateral, and vertical COM position and velocity were calculated using a full-body model and 7 models with reduced numbers of segments, which were compared with the full-body model. With removal of body segments, errors relative to the full-body model increased, while relationship strength decreased. The inclusion of body segments appeared to affect COM measures, particularly COM velocity. Findings suggest that the body segments may provide a means of improving the control of COM motion, primarily its velocity, during continuous, multidirectional perturbations, and constitute a step toward improving our understanding of how the limbs contribute to balance control in moving environments.

scholarly journals Effect of Leg Dominance on The Center-of-Mass Kinematics During an Inside-of-the-Foot Kick in Amateur Soccer Players

2014 ◽  
Vol 42 (1) ◽  
pp. 51-61 ◽  
Author(s):  
Matteo Zago ◽  
Andrea Francesco Motta ◽  
Andrea Mapelli ◽  
Isabella Annoni ◽  
Christel Galvani ◽  
...  
Keyword(s):  
Body Movement ◽  
Center Of Mass ◽  
Three Dimensional ◽  
The Body ◽  
Soccer Players ◽  
Upper Body ◽  
Whole Body ◽  
Movement Velocity ◽  
Ground Support ◽  
Analysis System

Abstract Soccer kicking kinematics has received wide interest in literature. However, while the instep-kick has been broadly studied, only few researchers investigated the inside-of-the-foot kick, which is one of the most frequently performed techniques during games. In particular, little knowledge is available about differences in kinematics when kicking with the preferred and non-preferred leg. A motion analysis system recorded the three-dimensional coordinates of reflective markers placed upon the body of nine amateur soccer players (23.0 ± 2.1 years, BMI 22.2 ± 2.6 kg/m2), who performed 30 pass-kicks each, 15 with the preferred and 15 with the non-preferred leg. We investigated skill kinematics while maintaining a perspective on the complete picture of movement, looking for laterality related differences. The main focus was laid on: anatomical angles, contribution of upper limbs in kick biomechanics, kinematics of the body Center of Mass (CoM), which describes the whole body movement and is related to balance and stability. When kicking with the preferred leg, CoM displacement during the ground-support phase was 13% higher (p<0.001), normalized CoM height was 1.3% lower (p<0.001) and CoM velocity 10% higher (p<0.01); foot and shank velocities were about 5% higher (p<0.01); arms were more abducted (p<0.01); shoulders were rotated more towards the target (p<0.01, 6° mean orientation difference). We concluded that differences in motor control between preferred and non-preferred leg kicks exist, particularly in the movement velocity and upper body kinematics. Coaches can use these results to provide effective instructions to players in the learning process, moving their focus on kicking speed and upper body behavior

scholarly journals Coordinated Ground Forces Exerted by Buttocks and Feet are Adequately Programmed for Weight Transfer During Sit-to-Stand

1999 ◽  
Vol 82 (6) ◽  
pp. 3021-3029 ◽  
Author(s):  
Helga Hirschfeld ◽  
Maria Thorsteinsdottir ◽  
Elisabeth Olsson
Keyword(s):  
Center Of Mass ◽  
Three Dimensional ◽  
The Body ◽  
Whole Body ◽  
Sit To Stand ◽  
Preparatory Phase ◽  
Base Distance ◽  
Left And Right ◽  
Hip Flexion ◽  
Weight Transfer

The purpose of this study was to test the hypothesis whether weight transfer during sit-to-stand (STS) is the result of coordinated ground forces exerted by buttocks and feet before seat-off. Whole-body kinematics and three-dimensional ground forces from left and right buttock as well as from left and right foot were recorded for seven adults during STS. We defined a preparatory phase from onset of the first detectable anterior/posterior (A/P) force to seat-off (buttock forces fell to 0) and a rising phase from seat-off to the decrease of center of mass (CoM) vertical velocity to zero. STS was induced by an increase of vertical and backward directed ground forces exerted by the buttocks that significantly preceded the onset of any trunk movement. All ground forces peaked before or around the moment of seat-off, whereas all kinematic variables, except trunk forward rotation and hip flexion, peaked after seat-off, during or after the rising phase. The present study suggests that the weight transfer from sit to stand is induced by ground forces exerted by buttocks and feet before seat-off, i.e., during the preparatory phase. The buttocks generate the isometric “rising forces,” e.g., the propulsive impulse for the forward acceleration of the body, while the feet apply adequate damping control before seat-off. This indicates that the rising movement is a result of these coordinated forces, targeted to match the subject's weight and support base distance between buttocks and feet. The single peaked, bell-shaped profiles peaking before seat-off, were seen beneath buttocks for the “rising drive,” i.e., between the time of peak backward directed force and seat-off, as well as beneath the feet for the “damping drive,” i.e., from onset to the peak of forward-directed force and for CoM A/P velocity. This suggests that both beginning and end of the weight transfer process are programmed before seat-off. The peak deceleration of A/P CoM took place shortly (∼100 ms) after CoM peak velocity, resulting in a well controlled CoM deceleration before seat-off. In contrast to the view of other authors, this suggests that body equilibrium is controlled during weight transfer.

Biomechanical Role of the Locomotor System in Controlling Body Center of Mass Motion in Older Adults During Obstructed Gait

2010 ◽  
Vol 26 (2) ◽  
pp. 195-203 ◽  
Author(s):  
T.-M. Wang ◽  
H.-L. Chen ◽  
W.-C. Hsu ◽  
M.-W. Liu ◽  
T.-W. Lu
Keyword(s):  
Center Of Mass ◽  
Three Dimensional ◽  
Knee Extensor ◽  
Frontal Plane ◽  
The Elderly ◽  
The Body ◽  
Mass Motion ◽  
Obstacle Crossing ◽  
Locomotor System ◽  
Risk Of Falls

AbstractFifteen young and fifteen older healthy adults walked and crossed obstacles of three different heights while kinematic data and ground reaction forces were acquired to calculate the three-dimensional motion of the centre of mass (COM) and lower limb joint moments. The older group had greater normalized jerk score of the COM. When the leading limb was crossing, the older group kept the COM more posterior and on the trailing stance limb for longer with increased knee extensor crossing moments and thus decreased anterioposterior COM deceleration. When the trailing limb was crossing, the older group decreased vertical COM deceleration through increased hip extensor crossing moments. The older group maintained the same COM motion as the young in the frontal plane with greater hip and knee abductor crossing moments. The older group exhibited significant kinetic changes in their locomotor system with increased muscular demand, leading to a more jerky motion of the body COM. However, these changes helped to maintain the frontal COM motion and to achieve a sagittal COM motion pattern which is thought to be helpful for a safe and successful obstacle-crossing. Failure to meet the kinetic demands in the elderly may increase the risk of falls during obstacle-crossing.

A Biomechanical Assessment of the Sliding Motion of Curling Delivery in Elite and Subelite Curlers

2012 ◽  
Vol 28 (6) ◽  
pp. 694-700 ◽  
Author(s):  
Kyoung-Seok Yoo ◽  
Hyun-Kyung Kim ◽  
Jin-Hoon Park
Keyword(s):  
Balance Control ◽  
Center Of Mass ◽  
Three Dimensional ◽  
The Body ◽  
Movement Speed ◽  
Biomechanical Assessment ◽  
Sliding Motion ◽  
Angular Velocities ◽  
Posterior Direction ◽  
The Moment

The present study examined the technical characteristics of sliding performance from push-off until stone release in curling delivery. Five elite performance level curlers (> 7 years experience) and five subelite level curlers (< 3 years experience) were analyzed during the action of delivery of a curling stone. The joint angles, angular velocities, and moments of the body center of mass (COM) were determined based on three-dimensional kinematic data. The plantar pressure data were measured using a validated in-shoe system. The results indicated that the gliding time and horizontal velocity of the mass center of the body during the sliding phase were not significantly different between the elite and subelite groups. However, there were significant differences in the gliding distance and the rate of changes in velocity profiles of body COM between the two groups. The moment of the body COM from its relative position to the ankle of the support limb in the anterior/posterior direction was positive in elite curlers and negative in subelite curlers. In addition, larger ankle dorsiflexion and greater contact area of the sliding foot were observed in elite curlers. These data suggest a superior ability of elite curlers to maintain a regulated movement speed and balance control during the performance of a curling stone delivery.

scholarly journals ANALYSIS OF DYNAMIC BALANCE CONTROL IN TRANSTIBIAL AMPUTEES WITH USE OF A POWERED PROSTHETIC FOOT

2016 ◽  
Vol 28 (02) ◽  
pp. 1650011
Author(s):  
Shaun C. Resseguie ◽  
Li Jin ◽  
Michael E. Hahn
Keyword(s):  
Balance Control ◽  
Dynamic Balance ◽  
Center Of Mass ◽  
Whole Body ◽  
Mass Motion ◽  
Camera System ◽  
Prosthetic Foot ◽  
Motion Data ◽  
Walking Speeds ◽  
Transtibial Amputees

Powered prosthetic feet (PPF) are designed to provide transtibial amputees (TTA) with active propulsion and range of motion similar to that of the biological limb. Previous studies have demonstrated the PPF’s ability to increase TTA walking speeds while reducing the energetic costs, however, little is known about its effects on dynamic balance control. The purpose of this pilot study was to assess dynamic balance control in TTA subjects during level ground walking and obstacle-crossing tasks. Control subjects ([Formula: see text]) and TTA subjects ([Formula: see text]) were instructed to complete a series of functional walking tasks. The TTA subjects completed the walking protocol twice, first in their passive energy-storing prosthetic foot (ESPF) and again in the prescribed PPF after two weeks of acclimation. Motion data were collected via a 10-camera system with a 53-marker and 15-segment body model. Whole body medial-lateral center of mass motion (displacement and peak velocity) was analyzed and used as a functional indicator of dynamic balance control. Findings indicate no difference in the dynamic balance control of TTA wearing the PPF compared to the ESPF. However, there was an observed trend of walking speed and obstacle height affecting balance control within the groups.

scholarly journals Reactive Postural Responses to Continuous Yaw Perturbations in Healthy Humans: The Effect of Aging

Sensors ◽  
2019 ◽  
Vol 20 (1) ◽  
pp. 63 ◽  
Author(s):  
Ilaria Mileti ◽  
Juri Taborri ◽  
Stefano Rossi ◽  
Zaccaria Del Prete ◽  
Marco Paoloni ◽  
...  
Keyword(s):  
Older Adults ◽  
Balance Control ◽  
Center Of Mass ◽  
Community Dwelling ◽  
Body Segments ◽  
Healthy Humans ◽  
Eyes Closed ◽  
Age Related ◽  
Postural Responses ◽  
Mass Displacement

Maintaining balance stability while turning in a quasi-static stance and/or in dynamic motion requires proper recovery mechanisms to manage sudden center-of-mass displacement. Furthermore, falls during turning are among the main concerns of community-dwelling elderly population. This study investigates the effect of aging on reactive postural responses to continuous yaw perturbations on a cohort of 10 young adults (mean age 28 ± 3 years old) and 10 older adults (mean age 61 ± 4 years old). Subjects underwent external continuous yaw perturbations provided by the RotoBit1D platform. Different conditions of visual feedback (eyes opened and eyes closed) and perturbation intensity, i.e., sinusoidal rotations on the horizontal plane at different frequencies (0.2 Hz and 0.3 Hz), were applied. Kinematics of axial body segments was gathered using three inertial measurement units. In order to measure reactive postural responses, we measured body-absolute and joint absolute rotations, center-of-mass displacement, body sway, and inter-joint coordination. Older adults showed significant reduction in horizontal rotations of body segments and joints, as well as in center-of-mass displacement. Furthermore, older adults manifested a greater variability in reactive postural responses than younger adults. The abnormal reactive postural responses observed in older adults might contribute to the well-known age-related difficulty in dealing with balance control during turning.

Biodynamic Characteristics of Upper Limb Reaching Movements of the Seated Human Under Whole-Body Vibration

2013 ◽  
Vol 29 (1) ◽  
pp. 12-22 ◽  
Author(s):  
Heon-Jeong Kim ◽  
Bernard J. Martin
Keyword(s):  
Right Hemisphere ◽  
Whole Body Vibration ◽  
The Body ◽  
Upper Body ◽  
Whole Body ◽  
Vibration Transmission ◽  
Body Vibration ◽  
Body Segments ◽  
Human Movements ◽  
Reach Movements

Simulation of human movements is an essential component for proactive ergonomic analysis and biomechanical model development (Chaffin, 2001). Most studies on reach kinematics have described human movements in a static environment, however the models derived from these studies cannot be applied to the analysis of human reach movements in vibratory environments such as in-vehicle operations. This study analyzes three-dimensional joint kinematics of the upper extremity in reach movements performed in static and specific vibratory conditions and investigates vibration transmission to shoulder, elbow, and hand along the body path during pointing tasks. Thirteen seated subjects performed reach movements to five target directions distributed in their right hemisphere. The results show similarities in the characteristics of movement patterns and reach trajectories of upper body segments for static and dynamic environments. In addition, vibration transmission through upper body segments is affected by vibration frequency, direction, and location of the target to be reached. Similarities in the pattern of movement trajectories revealed by filtering vibration-induced oscillations indicate that coordination strategy may not be drastically different in static and vibratory environments. This finding may facilitate the development of active biodynamic models to predict human performance and behavior under whole body vibration exposure.

scholarly journals Sensorimotor feedback based on task-relevant error robustly predicts temporal recruitment and multidirectional tuning of muscle synergies

2013 ◽  
Vol 109 (1) ◽  
pp. 31-45 ◽  
Author(s):  
Seyed A. Safavynia ◽  
Lena H. Ting
Keyword(s):  
Sagittal Plane ◽  
Balance Control ◽  
Center Of Mass ◽  
The Body ◽  
Muscle Synergy ◽  
Muscle Synergies ◽  
Muscle Coordination ◽  
Initial State ◽  
Sensorimotor Feedback ◽  
Task Level

We hypothesized that motor outputs are hierarchically organized such that descending temporal commands based on desired task-level goals flexibly recruit muscle synergies that specify the spatial patterns of muscle coordination that allow the task to be achieved. According to this hypothesis, it should be possible to predict the patterns of muscle synergy recruitment based on task-level goals. We demonstrated that the temporal recruitment of muscle synergies during standing balance control was robustly predicted across multiple perturbation directions based on delayed sensorimotor feedback of center of mass (CoM) kinematics (displacement, velocity, and acceleration). The modulation of a muscle synergy's recruitment amplitude across perturbation directions was predicted by the projection of CoM kinematic variables along the preferred tuning direction(s), generating cosine tuning functions. Moreover, these findings were robust in biphasic perturbations that initially imposed a perturbation in the sagittal plane and then, before sagittal balance was recovered, perturbed the body in multiple directions. Therefore, biphasic perturbations caused the initial state of the CoM to differ from the desired state, and muscle synergy recruitment was predicted based on the error between the actual and desired upright state of the CoM. These results demonstrate that that temporal motor commands to muscle synergies reflect task-relevant error as opposed to sensory inflow. The proposed hierarchical framework may represent a common principle of motor control across motor tasks and levels of the nervous system, allowing motor intentions to be transformed into motor actions.

Impairments of Postural Balance in Surgically Treated Lumbar Disc Herniation Patients

2020 ◽  
Vol 36 (4) ◽  
pp. 228-234
Author(s):  
Ziva M. Rosker ◽  
Jernej Rosker ◽  
Nejc Sarabon
Keyword(s):  
Postural Balance ◽  
Center Of Pressure ◽  
Balance Control ◽  
The Body ◽  
Surface Velocity ◽  
Body Sway ◽  
Support Surface ◽  
Balance Task ◽  
Lateral Body ◽  
Unstable Support

Reports on body sway control following microdiscectomy lack reports on side-specific balance deficits as well as the effects of trunk balance control deficits on body sway during upright stances. About 3 weeks post microdiscectomy, the body sway of 27 patients and 25 controls was measured while standing in an upright quiet stance with feet positioned parallel on an unstable support surface, a tandem stance with the involved leg positioned in front or at the back, a single-leg stance with both legs, and sitting on an unstable surface. Velocity, average amplitude, and frequency-direction–specific parameters were analyzed from the center of pressure movement, measured by the force plate. Statistically significant differences between the 2 groups were observed for the medial–lateral body sway frequency in parallel stance on a stable and unstable support surface and for the sitting balance task in medial-lateral body sway parameters. Medium to high correlations were observed between body sway during sitting and the parallel stance, as well as between the tandem and single-legged stances. Following microdiscectomy, deficits in postural balance were side specific, as expected by the nature of the pathology. In addition, the results of this study confirmed the connection between proximal balance control deficits and balance during upright quiet balance tasks.

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