scholarly journals Potential Mediators of Load-Related Changes in Movement Complexity in Young, Healthy Adults

2019 ◽  
Vol 54 (1) ◽  
pp. 70-80
Author(s):  
Stephen M. Glass ◽  
Christopher K. Rhea ◽  
Randy J. Schmitz ◽  
Scott E. Ross
Keyword(s):  
Range Of Motion ◽  
Center Of Pressure ◽  
Multiscale Entropy ◽  
Behavioral Complexity ◽  
Varying Coefficients ◽  
Movement Screening ◽  
Reaction Forces ◽  
Multivariate Multiscale Entropy ◽  
Few Data ◽  
Optimal Movement

Context Movement screening has become increasingly popular among tactical professionals. This popularity has motivated the design of interventions that cater to improving outcomes on the screens themselves, which are often scored in reference to an objective norm. In contrast to the assumptions underlying this approach, dynamical systems theory suggests that movements arise as a function of continuously evolving constraints and that optimal movement strategies may not exist. To date, few data address behavioral complexity in the fundamental movement tasks commonly used in clinical screenings. Objective To provide evidence of complex variability during movement screens and test the role of modifiable—that is, trainable—constraints in mediating loss of complexity during experimental-task manipulations. Design Crossover study. Setting Research laboratory. Patients or Other Participants Twenty-five male (age = 23.96 ± 3.74 years, height = 178.82 ± 7.51 cm, mass = 79.66 ± 12.66 kg) and 25 female (age = 22.00 ± 2.02 years, height = 165.40 ± 10.24 cm, mass = 63.98 ± 11.07 kg) recreationally active adults. Intervention(s) Participants performed tests of balance, range of motion, and strength. Additionally, they performed cyclical movement tasks under a control (C) condition and while wearing an 18.10-kg weight vest (W). Main Outcome Measure(s) Ground reaction forces were sampled at 1000 Hz and used to calculate center of pressure during cyclical movement tests. Multivariate multiscale entropy (MMSE) for the center-of-pressure signal was then calculated. Condition effects (C versus W) were analyzed using paired t tests, and penalized varying-coefficients regression was used to identify models predicting entropy outcomes from balance, range of motion, and strength. Results The MMSE decreased during the W condition (MMSEC > MMSEW; t49 range = 3.17–5.21; all P values < .01). Conclusions Moderate evidence supported an association between modifiable constraints and behavioral complexity, but a role in mediating load-related loss of complexity was not demonstrated.

scholarly journals Resistance Training Exercise Program for Intervention to Enhance Gait Function in Elderly Chronically Ill Patients: Multivariate Multiscale Entropy for Center of Pressure Signal Analysis

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Ming-Shu Chen ◽  
Bernard C. Jiang
Keyword(s):  
Resistance Training ◽  
Chronic Diseases ◽  
Postural Stability ◽  
Center Of Pressure ◽  
Chronically Ill ◽  
The Elderly ◽  
Multiscale Entropy ◽  
Gait Function ◽  
Multivariate Multiscale Entropy ◽  
Chronically Ill Patients

Falls are unpredictable accidents, and the resulting injuries can be serious in the elderly, particularly those with chronic diseases. Regular exercise is recommended to prevent and treat hypertension and other chronic diseases by reducing clinical blood pressure. The “complexity index” (CI), based on multiscale entropy (MSE) algorithm, has been applied in recent studies to show a person’s adaptability to intrinsic and external perturbations and widely used measure of postural sway or stability. The multivariate multiscale entropy (MMSE) was advanced algorithm used to calculate the complexity index (CI) values of the center of pressure (COP) data. In this study, we applied the MSE & MMSE to analyze gait function of 24 elderly, chronically ill patients (44% female; 56% male; mean age,67.56±10.70years) with either cardiovascular disease, diabetes mellitus, or osteoporosis. After a 12-week training program, postural stability measurements showed significant improvements. Our results showed beneficial effects of resistance training, which can be used to improve postural stability in the elderly and indicated that MMSE algorithms to calculate CI of the COP data were superior to the multiscale entropy (MSE) algorithm to identify the sense of balance in the elderly.

scholarly journals Multivariate Multiscale Entropy Applied to Center of Pressure Signals Analysis: An Effect of Vibration Stimulation of Shoes

Entropy ◽  
2012 ◽  
Vol 14 (11) ◽  
pp. 2157-2172 ◽  
Author(s):  
Qin Wei ◽  
Dong-Hai Liu ◽  
Kai-Hong Wang ◽  
Quan Liu ◽  
Maysam Abbod ◽  
...  
Keyword(s):  
Center Of Pressure ◽  
Multiscale Entropy ◽  
Multivariate Multiscale Entropy ◽  
Stimulation Of

scholarly journals Measuring Center of Pressure Signals to Quantify Human Balance Using Multivariate Multiscale Entropy by Designing a Force Platform

Sensors ◽  
2013 ◽  
Vol 13 (8) ◽  
pp. 10151-10166 ◽  
Author(s):  
Cheng-Wei Huang ◽  
Pei-Der Sue ◽  
Maysam Abbod ◽  
Bernard Jiang ◽  
Jiann-Shing Shieh
Keyword(s):  
Center Of Pressure ◽  
Force Platform ◽  
Multiscale Entropy ◽  
Human Balance ◽  
Multivariate Multiscale Entropy

scholarly journals Active foot placement control ensures stable gait: Effect of constraints on foot placement and ankle moments

PLoS ONE ◽  
2020 ◽  
Vol 15 (12) ◽  
pp. e0242215
Author(s):  
A. M. van Leeuwen ◽  
J. H. van Dieën ◽  
A. Daffertshofer ◽  
S. M. Bruijn
Keyword(s):  
Steady State ◽  
Center Of Pressure ◽  
Center Of Mass ◽  
Reaction Force ◽  
Stride Frequency ◽  
Tight Control ◽  
Foot Placement ◽  
Ankle Moment ◽  
Reaction Forces ◽  
Moment Control

Step-by-step foot placement control, relative to the center of mass (CoM) kinematic state, is generally considered a dominant mechanism for maintenance of gait stability. By adequate (mediolateral) positioning of the center of pressure with respect to the CoM, the ground reaction force generates a moment that prevents falling. In healthy individuals, foot placement is complemented mainly by ankle moment control ensuring stability. To evaluate possible compensatory relationships between step-by-step foot placement and complementary ankle moments, we investigated the degree of (active) foot placement control during steady-state walking, and under either foot placement-, or ankle moment constraints. Thirty healthy participants walked on a treadmill, while full-body kinematics, ground reaction forces and EMG activities were recorded. As a replication of earlier findings, we first showed step-by-step foot placement is associated with preceding CoM state and hip ab-/adductor activity during steady-state walking. Tight control of foot placement appears to be important at normal walking speed because there was a limited change in the degree of foot placement control despite the presence of a foot placement constraint. At slow speed, the degree of foot placement control decreased substantially, suggesting that tight control of foot placement is less essential when walking slowly. Step-by-step foot placement control was not tightened to compensate for constrained ankle moments. Instead compensation was achieved through increases in step width and stride frequency.

scholarly journals Effects of additional load at different heights on gait initiation: A statistical parametric mapping of center of pressure and center of mass behavior

PLoS ONE ◽  
2021 ◽  
Vol 16 (6) ◽  
pp. e0242892
Author(s):  
Marcus Fraga Vieira ◽  
Fábio Barbosa Rodrigues ◽  
Alfredo de Oliveira Assis ◽  
Eduardo de Mendonça Mesquita ◽  
Thiago Santana Lemes ◽  
...  
Keyword(s):  
Time Series ◽  
Center Of Pressure ◽  
Center Of Mass ◽  
Statistical Parametric Mapping ◽  
Gait Initiation ◽  
Experimental Conditions ◽  
Distributed Load ◽  
Uniformly Distributed Load ◽  
Reaction Forces ◽  
Controlled Object

The purpose of this study was to investigate the effects of different vertical positions of an asymmetrical load on the anticipatory postural adjustments phase of gait initiation. Sixty-eight college students (32 males, 36 females; age: 23.65 ± 3.21 years old; weight: 69.98 ± 8.15 kg; height: 1.74 ± 0.08 m) were enrolled in the study. Ground reaction forces and moments were collected using two force platforms. The participants completed three trials under each of the following random conditions: no-load (NL), waist uniformly distributed load (WUD), shoulder uniformly distributed load (SUD), waist stance foot load (WST), shoulder stance foot load (SST), waist swing foot load (WSW), and shoulder swing foot load (SSW). The paired Hotelling’s T-square test was used to compare the experimental conditions. The center of pressure (COP) time series were significantly different for the SUD vs. NL, SST vs. NL, WST vs. NL, and WSW vs. NL comparisons. Significant differences in COP time series were observed for all comparisons between waist vs. shoulder conditions. Overall, these differences were greater when the load was positioned at the shoulders. For the center of mass (COM) time series, significant differences were found for the WUD vs. NL and WSW vs. NL conditions. However, no differences were observed with the load positioned at the shoulders. In conclusion, only asymmetrical loading at the waist produced significant differences, and the higher the extra load, the greater the effects on COP behavior. By contrast, only minor changes were observed in COM behavior, suggesting that the changes in COP (the controller) behavior are adjustments to maintain the COM (controlled object) unaltered.

scholarly journals Response to Tendon Vibration Questions the Underlying Rationale of Proprioceptive Training

2017 ◽  
Vol 52 (2) ◽  
pp. 97-107 ◽  
Author(s):  
Anat Vilnai Lubetzky ◽  
Sarah Westcott McCoy ◽  
Robert Price ◽  
Deborah Kartin
Keyword(s):  
Achilles Tendon ◽  
Center Of Pressure ◽  
Multiscale Entropy ◽  
Support Surface ◽  
Ankle Sprains ◽  
Control Mechanisms ◽  
Tendon Vibration ◽  
Healthy Group ◽  
Proprioceptive Training ◽  
Proprioceptive Function

Context: Proprioceptive training on compliant surfaces is used to rehabilitate and prevent ankle sprains. The ability to improve proprioceptive function via such training has been questioned. Achilles tendon vibration is used in motor-control research as a form of proprioceptive stimulus. Using measures of postural steadiness with nonlinear measures to elucidate control mechanisms, tendon vibration can be applied to investigate the underlying rationale of proprioceptive training. Objective: To test whether the effect of vibration on young adults' postural control depended on the support surface. Design: Descriptive laboratory study. Setting: Research laboratory. Patients or Other Participants: Thirty healthy adults and 10 adults with chronic ankle instability (CAI; age range = 18−40 years). Intervention(s): With eyes open, participants stood in bilateral stance on a rigid plate (floor), memory foam, and a Both Sides Up (BOSU) ball covering a force platform. We applied bilateral Achilles tendon vibration for the middle 20 seconds in a series of 60-second trials and analyzed participants' responses from previbration to vibration (pre-vib) and from vibration to postvibration (vib-post). Main Outcome Measure(s): We calculated anterior-posterior excursion of the center of pressure and complexity index derived from the area under multiscale entropy curves. Results: The excursion response to vibration differed by surface, as indicated by a significant interaction of P < .001 for the healthy group at both time points and for the CAI group vib-post. Although both groups demonstrated increased excursion from pre-vib and from vib-post, a decrease was observed on the BOSU. The complexity response to vibration differed by surface for the healthy group (pre-vib, P < .001). The pattern for the CAI group was similar but not significant. Complexity changes vib-post were the same on all surfaces for both groups. Conclusions: Participants reacted less to ankle vibration when standing on the BOSU as compared with the floor, suggesting that proprioceptive training may not be occurring. Different balance-training paradigms to target proprioception, including tendon vibration, should be explored.

scholarly journals Potential Mediators of Load-Related Decreases in Movement Quality in Young, Healthy Adults

2019 ◽  
Vol 54 (1) ◽  
pp. 81-89
Author(s):  
Stephen M. Glass ◽  
Randy J. Schmitz ◽  
Christopher K. Rhea ◽  
Scott E. Ross
Keyword(s):  
Range Of Motion ◽  
Physical Performance ◽  
Professional Community ◽  
Performance Outcomes ◽  
Functional Movement Screen ◽  
Functional Movement ◽  
Movement Quality ◽  
Varying Coefficients ◽  
Item Scores ◽  
Weighted Vest

Context Predicting and promoting physical performance are important goals within the tactical professional community. Movement screens are frequently used in this capacity but are poor predictors of performance outcomes. It has recently been shown that prediction improved when movement quality was evaluated under load, but the mechanisms underlying this improvement remain unclear. Because balance, range of motion, and strength are mutually relevant to physical performance and movement quality, these attributes may mediate load-related decreases in movement quality and account for the resulting increase in performance prediction. Objective To quantify the roles of balance, range of motion, and strength in mediating load-related decreases in clinical movement-screen scores. Design Crossover study. Setting Research laboratory. Patients or Other Participants Twenty-five male (age = 23.96 ± 3.74 years, height = 178.82 ± 7.51 cm, mass = 79.66 ± 12.66 kg) and 25 female (age = 22.00 ± 2.02 years, height = 165.40 ± 10.24 cm, mass = 63.98 ± 11.07 kg) recreationally active adults. Intervention(s) Participants completed a clinical movement screen under a control condition and while wearing an 18.10-kg weighted vest as well as tests of balance, range of motion, and strength. Main Outcome Measure(s) Item score differences were assessed using Wilcoxon signed rank tests for matched pairs. Interactions between (1) balance, range of motion, and strength and (2) load condition were modeled using penalized varying-coefficients regression with item scores as the dependent measure. Results Except for the hurdle step, item scores were lower in the weighted-vest than in the control condition for all tests (P < .05). Except for rotary stability, F statistics were significant for all models (P values < .05, R2 values = 0.22–0.77). Main effects of balance, range of motion, and strength on Functional Movement Screen scores were observed (P < .05); however, little evidence was found to suggest that these attributes mediated load-related decreases in Functional Movement Screen item scores. Conclusions Balance, range of motion, and strength affected movement quality but did not mediate the effect of the load treatment.

scholarly journals Effect of Toe Type on Static Balance in Ballet Dancers

2020 ◽  
Vol 35 (1) ◽  
pp. 35-41
Author(s):  
Momoko Kizawa ◽  
Toshito Yasuda ◽  
Hiroaki Shima ◽  
Katsunori Mori ◽  
Seiya Tsujinaka ◽  
...  
Keyword(s):  
Postural Stability ◽  
Center Of Pressure ◽  
Ground Reaction Forces ◽  
Bipedal Stance ◽  
Ballet Dancers ◽  
Maximum Range ◽  
Trajectory Length ◽  
Reaction Forces ◽  
Second Toe ◽  
Anterior Posterior

OBJECTIVES: Some forefoot shapes are ideal for pointe work in ballet. Egyptian-type, with the hallux being longest and the remaining toes decreasing in size, and Greek-type, with the second toe longer than the hallux, are considered less optimal for pointe work. Square-type, with the second toe the same length as the hallux, is considered optimal. This study compared postural stability in the bipedal stance, demi pointe, and en pointe between ballet dancers with the two toe types using a stabilometer. METHODS: This study included 25 Japanese ballet academy dancers who had received ballet lessons for at least 6 years. Toes were categorized into Egyptian-type (n=14) and square-type (n=11). Bipedal stance, demi pointe, and en pointe were tested. Center of pressure (COP) parameters were calculated from ground-reaction forces using two force plates: total trajectory length (LNG), velocities of anterior-posterior (VAP) and medial-lateral directions (VML), and maximum range displacement in the anterior-posterior (MAXAP) and medial-lateral directions (MAXML). Mann-Whitney U-tests were used to examine differences in COP parameters. RESULTS: There were no differences in parameters during bipedal stance or demi pointe. However, dancers with Egyptian-type toes had significantly greater LNG (p<0.01), VML (p=0.01), MAXML (p<0.01), and MAXAP (p=0.03) during en pointe. CONCLUSIONS: Ballet dancers with Egyptian-type toes demonstrated greater displacement in the medial-lateral and anterior-posterior directions during en pointe. Ballet dancers should be aware of toe types and sway character to optimize ballet training and balance.

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