Standardizing Methodology for Research with Uneven Terrains Focused on Dynamic Balance During Gait

2016 ◽  
Vol 32 (6) ◽  
pp. 599-602
Author(s):  
Timothy D. Coleman ◽  
Haley J. Lawrence ◽  
W. Lee Childers
Keyword(s):  
Angular Momentum ◽  
Sagittal Plane ◽  
Dynamic Balance ◽  
Human Gait ◽  
Camera Motion ◽  
Step Width ◽  
Arm Swing ◽  
Margin Of Stability ◽  
Significant Difference ◽  
Trunk Sway

This research tested a reproducible uneven walkway designed to destabilize human gait. Ten participants walked 30 times over even and uneven (7.3 × .08 m, sequentially-placed wooden blocks in a rotating pattern, 1-cm thick rubber mat) walkways. A full-body marker set and 8-camera motion capture system recorded limb kinematics. MatLab 2013b was used to calculate measures of gait stability: angular momentum, margin of stability, step width variability, CoM height, toe clearance, lateral arm swing. The minimum number of strides necessary to minimize intraparticipant variability was calculated via the interquartile range/median ratio (IMR) at 25% and 10% thresholds for each measure. A paired t test tested for significance between terrains (P < .05). The uneven walkway significantly destabilized gait as seen by increases in: coronal and sagittal plane angular momentum, step width variability, and toe clearance. We found no significant difference with the margin of stability between the 2 terrains possibly due to compensatory strategies (eg, lateral arm swing, trunk sway, step width). Recording a minimum of 10 strides per subject will keep each variable between the 25% and 10% IMR thresholds. In conclusion, the uneven walkway design significantly destabilizes human gait and at least 10 strides should be collected per subject.

scholarly journals Using Biofeedback to Reduce Step Length Asymmetry Impairs Dynamic Balance in People Poststroke

2021 ◽  
pp. 154596832110193
Author(s):  
Sungwoo Park ◽  
Chang Liu ◽  
Natalia Sánchez ◽  
Julie K. Tilson ◽  
Sara J. Mulroy ◽  
...  
Keyword(s):  
Angular Momentum ◽  
Sagittal Plane ◽  
Dynamic Balance ◽  
Objective Measure ◽  
Frontal Plane ◽  
Step Length ◽  
Berg Balance Scale ◽  
Whole Body ◽  
Functional Gait ◽  
Full Body

Background People poststroke often walk with a spatiotemporally asymmetric gait, due in part to sensorimotor impairments in the paretic lower extremity. Although reducing asymmetry is a common objective of rehabilitation, the effects of improving symmetry on balance are yet to be determined. Objective We established the concurrent validity of whole-body angular momentum as a measure of balance, and we determined if reducing step length asymmetry would improve balance by decreasing whole-body angular momentum. Methods We performed clinical balance assessments and measured whole-body angular momentum during walking using a full-body marker set in a sample of 36 people with chronic stroke. We then used a biofeedback-based approach to modify step length asymmetry in a subset of 15 of these individuals who had marked asymmetry and we measured the resulting changes in whole-body angular momentum. Results When participants walked without biofeedback, whole-body angular momentum in the sagittal and frontal plane was negatively correlated with scores on the Berg Balance Scale and Functional Gait Assessment supporting the validity of whole-body angular momentum as an objective measure of dynamic balance. We also observed that when participants walked more symmetrically, their whole-body angular momentum in the sagittal plane increased rather than decreased. Conclusions Voluntary reductions of step length asymmetry in people poststroke resulted in reduced measures of dynamic balance. This is consistent with the idea that after stroke, individuals might have an implicit preference not to deviate from their natural asymmetry while walking because it could compromise their balance. Clinical Trials Number: NCT03916562.

Muscle Contributions to Balance Control During Amputee and Nonamputee Stair Ascent

2020 ◽  
Vol 142 (12) ◽  
Author(s):  
Nicole G. Harper ◽  
Jason M. Wilken ◽  
Richard R. Neptune
Keyword(s):  
Angular Momentum ◽  
Lower Limb ◽  
Sagittal Plane ◽  
Balance Control ◽  
Dynamic Balance ◽  
Frontal Plane ◽  
Rate Of Change ◽  
Prosthetic Devices ◽  
Stair Ascent

Abstract Dynamic balance is controlled by lower-limb muscles and is more difficult to maintain during stair ascent compared to level walking. As a result, individuals with lower-limb amputations often have difficulty ascending stairs and are more susceptible to falls. The purpose of this study was to identify the biomechanical mechanisms used by individuals with and without amputation to control dynamic balance during stair ascent. Three-dimensional muscle-actuated forward dynamics simulations of amputee and nonamputee stair ascent were developed and contributions of individual muscles, the passive prosthesis, and gravity to the time rate of change of angular momentum were determined. The prosthesis replicated the role of nonamputee plantarflexors in the sagittal plane by contributing to forward angular momentum. The prosthesis largely replicated the role of nonamputee plantarflexors in the transverse plane but resulted in a greater change of angular momentum. In the frontal plane, the prosthesis and nonamputee plantarflexors contributed oppositely during the first half of stance while during the second half of stance, the prosthesis contributed to a much smaller extent. This resulted in altered contributions from the intact leg plantarflexors, vastii and hamstrings, and the intact and residual leg hip abductors. Therefore, prosthetic devices with altered contributions to frontal-plane angular momentum could improve balance control during amputee stair ascent and minimize necessary muscle compensations. In addition, targeted training could improve the force production magnitude and timing of muscles that regulate angular momentum to improve balance control.

scholarly journals Manual stabilization reveals a transient role for balance control during locomotor adaptation

2019 ◽  
Author(s):  
Sungwoo Park ◽  
James M. Finley
Keyword(s):  
Angular Momentum ◽  
Balance Control ◽  
Dynamic Balance ◽  
Step Length ◽  
Bipedal Walking ◽  
Whole Body ◽  
Arm Swing ◽  
Angular Momenta ◽  
After Effect ◽  
Potential Factor

AbstractA fundamental feature of human locomotor control is the need to adapt our walking pattern in response to changes in the environment. For example, when people walk on a split-belt treadmill which has belts that move at different speeds, they adapt to the asymmetric speed constraints by reducing their spatiotemporal asymmetry. Here, we aim to understand the role of stability as a potential factor driving this adaptation process. We recruited 24 healthy, young adults to adapt to walking on a split-belt treadmill while either holding on to a handrail or walking with free arm swing. We measured whole-body angular momentum and step length asymmetry as measures of dynamic balance and spatiotemporal asymmetry, respectively. To understand how changes in intersegmental coordination influenced measures of dynamic balance, we also measured segmental angular momenta and the coefficient of limb cancellation. When participants were initially exposed to the asymmetry in belt speeds, we observed an increase in whole-body angular momentum that was due to both an increase in the momentum of individual limb segments and a reduction in limb cancellation. Holding on to a handrail reduced the perturbation to asymmetry during the early phase of adaptation and resulted in a smaller after-effect during post-adaptation. In addition, the stabilization provided by holding on to a handrail led to reductions in the coupling between angular momentum and asymmetry. These results suggest that regulation of dynamic balance is most important during the initial, transient phase of adaptation to walking on a split-belt treadmill.Summary StatementRegulation of balance exhibits a transient effect on adaptation to imposed asymmetries during bipedal walking. External stabilization attenuates initial deviations in spatiotemporal asymmetry but has no effect on subsequent adaptation.

scholarly journals Effect of Milwaukee brace on static and dynamic balance of female hyperkyphotic adolescents

2012 ◽  
Vol 37 (1) ◽  
pp. 76-84 ◽  
Author(s):  
Arezoo Eshraghi ◽  
Nader Maroufi ◽  
Mohammad Ali Sanjari ◽  
Hassan Saeedi ◽  
Mohammad Reza Keyhani ◽  
...  
Keyword(s):  
Sagittal Plane ◽  
Center Of Pressure ◽  
Balance Control ◽  
Dynamic Balance ◽  
Normal Subjects ◽  
Balance Performance ◽  
Functional Reach ◽  
Significant Difference ◽  
The Right ◽  
Milwaukee Brace

Background: Biomechanical factors, such as spinal deformities can result in balance control disorders. Objectives: The purpose of this study was to examine the effect of bracing on static and dynamic balance control of hyperkyphotic female adolescents. Study Design: Clinical trial. Methods: A force platform was employed to record center of pressure (COP) parameters. Ten adolescents undergoing Milwaukee brace for hyperkyphosis and 14 normal subjects participated in the study. The COP data were collected with and without brace immediately on first day and after 120 days of continuous brace wear. Results: No significant difference was found in dynamic and static balance tests with and without brace on the first day ( P > 0.05). After 120 days, the values of COP displacement in functional reach to the right and left for the hyperkyphotic adolescents when performing without brace enhanced significantly compared to the first day. The forward reach distance was not significantly different between the normal and hyperkyphotic subjects ( P = 0.361); however, hyperkyphotic participants had significantly smaller reach distance in the functional reach to the right (21.88 vs. 25.56cm) and left (17.04 vs. 21.25cm). Conclusion: It might be concluded that bracing had a possible effect on improvement of dynamic balance performance, because the subjects could reach the target in dynamic reach tests with higher displacement in sagittal plane without losing their balance control. Clinical relevance Little is known about the biomechanical aspects of brace wear in individuals with hyperkyphosis. This study investigated balance differences between the healthy and hyperkyphotic individuals, and outcomes of Milwaukee brace wear. It might provide some new insight into the conservative treatment of hyperkyphosis for clinicians and researchers.

scholarly journals Recovery of dynamic stability during slips unaffected by arm swing in people with Parkinson’s Disease

PLoS ONE ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. e0249303
Author(s):  
Tarique Siragy ◽  
Allen Hill ◽  
Julie Nantel
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Calculated Data ◽  
Step Length ◽  
Step Width ◽  
Arm Swing ◽  
Margin Of Stability ◽  
Recovery Response ◽  
Arm Elevation ◽  
Arm Motion

The arm elevation strategy assists in recovering stability during slips in healthy young and elderly individuals. However, in people with Parkinson’s Disease, one of the main motor symptoms affecting the upper limbs is reduced arm swing which intensifies throughout the course of the disease before becoming absent. This holds direct implications for these individuals when encountering slips as the arm elevation strategy is an integral component in the interlimb slip response to restore stability. Arm swing’s effect in recovering from slips in people with Parkinson’s Disease though remains unexamined. Twenty people with Parkinson’s Disease (63.78 ± 8.97 years) walked with restricted and unrestricted arm swing conditions on a dual-belt treadmill where slips were induced on the least and most affected sides. Data were collected on the CAREN Extended System (Motek Medical, Amsterdam, NL). The Margin of Stability, linear and angular trunk velocities, as well as step length, time, and width were calculated. Data were examined during the slipped step and recovery step. The restricted arm swing condition, compared to unrestricted, caused a faster step time during the slipped step. Compared to the most affected leg, the least affected had a wider step width during the slipped step. During the recovery step, the least affected leg had a larger anteroposterior Margin of Stability and longer step time than the most affected. No differences between our arm swing conditions suggests that the normal arm swing in our participants was not more effective at restoring stability after an induced slip compared to when their arm motion was restricted. This may be due to the arm elevation strategy being ineffective in counteracting the slip’s backward destabilization in these individuals. Differences between the legs revealed that our participants were asymmetrically impaired in their slip recovery response.

Ankle Stabilizers Affect Agility but Not Vertical Jump or Dynamic Balance Performance

2011 ◽  
Vol 4 (6) ◽  
pp. 354-360 ◽  
Author(s):  
Jatin P. Ambegaonkar ◽  
Charles J. Redmond ◽  
Christa Winter ◽  
Nelson Cortes ◽  
Shruti J. Ambegaonkar ◽  
...  
Keyword(s):  
Repeated Measures ◽  
Sagittal Plane ◽  
Dynamic Balance ◽  
Vertical Jump ◽  
Plane Motion ◽  
Balance Performance ◽  
Level Of Evidence ◽  
Balance Test ◽  
Jump Test ◽  
Significant Difference

Ankle stabilizers can reduce ankle sprain incidence and severity by limiting range of motion. Still whether using them affects performance remains unclear. The authors compared effects of 3 ankle stabilizers, tape, lace-up (Swede-O Ankle Lok), and semirigid (Air-Cast Air-Stirrup) braces, and a nonsupport control on vertical jump (Sargent Jump Test), agility (Right-Boomerang Run test), and dynamic balance (Modified Bass Test) in 10 volunteers (4 males, 6 females; 25.6 ± 2.8 years, 167.8 ± 13.7 cm, 61.4 ± 10.7 kg) using repeated-measures ANOVAs. Participants had similar vertical jump ( P = .27; control = 41.40 ± 11.89 cm, tape = 37.90 ± 7.92 cm, Swede-O = 41.40 ± 11.89 cm, Air-Cast = 39.29 ± 10.85 cm) and dynamic balance ( P = .08; control = 92.50 ± 2.46, tape = 91.55 ± 3.53, Swede-O = 97.00 ± 5.32, Air-Cast = 89.40 ± 6.08) but differing agility scores ( P = .03; control = 13.55 ± 1.35 seconds, tape = 14.03 ± 1.5 seconds, Swede-O = 14.10 ± 1.36 seconds, Air-Cast = 14.14 ± 1.41 seconds). Post hoc tests revealed a significant difference ( P = .03) between control and Air-Cast but not between Swede-O ( P = .06) or tape ( P = .07). Effect size ( d) analyses indicated that compared with control, all stabilizers trended to increase agility run times (tape, d = 0.33; Swede-O, d = 0.40; Air-Cast, d = 0.43). Since participants primarily required sagittal plane motion when jumping vertically and had relatively slow directional changes in the dynamic balance test, wearing ankle stabilizers did not hamper jump or balance. However, ankle stabilizers hindered participants’ ability to perform quick directional changes required in the agility test, with the most rigid stabilizer (Air-Cast) affecting agility the most. Clinicians should be aware that ankle stabilizers may affect some performance measures (agility) but not others (jumping, balance) and continue examinations in larger cohorts. Level of Evidence: Therapeutic, Level II

Whole-Body Balancing Criteria for Biped Robots in Sagittal Plane

2019 ◽  
Author(s):  
Carlotta Mummolo ◽  
William Z. Peng ◽  
Joo H. Kim
Keyword(s):  
Angular Momentum ◽  
Sagittal Plane ◽  
Stability Boundary ◽  
Whole Body ◽  
Robotic Platform ◽  
Arm Swing ◽  
Floating Base ◽  
Space Dynamics ◽  
Balance Stability

Abstract In this work, the role of swing limb dynamics in the stabilization of legged systems is investigated. To quantify the contribution of arm swing during whole-body balancing, the balancing capability of a bipedal robotic platform is evaluated computationally during single and double foot contact for two configurations: arms fixed and arms free to move. The balancing capability with each arm configuration is evaluated by constructing its corresponding balance stability boundary, a threshold between balanced and falling states that includes all possible center of mass (COM) states that are balanced with respect to the specified arm and foot contact configuration. In this analysis, the bipedal robotic platform is modeled as a kinematic tree structure with floating-base dynamics in the sagittal plane. In addition to floating-base and joint-space dynamics, the complete COM-space dynamics of the system is established, including the formulation of the angular momentum (and its rate) of each rigid link, as well as a model of actuation dynamics based on motor characteristics. The comparison of the two balance stability regions yields both a quantitative measure of the enhancement in total balance capability and qualitative insights into the mechanism by which arm swing leads to enhanced capability. The role of arm swing angular momentum is also analyzed from the robot’s experimental gait trajectories as a potential means of benchmarking controller performance.

scholarly journals Influence of Arm Swing on Cost of Transport during Walking

2018 ◽  
Author(s):  
Myriam L. de Graaf ◽  
Juul Hubert ◽  
Han Houdijk ◽  
Sjoerd M. Bruijn
Keyword(s):  
Angular Momentum ◽  
Metabolic Energy ◽  
Energetic Cost ◽  
Healthy Individuals ◽  
Cost Of Transport ◽  
Arm Swing ◽  
Significant Difference ◽  
Summary Statement ◽  
The Cost ◽  
Healthy Participants

ABSTRACTNormal arm swing plays a role in decreasing the cost of transport during walking. However, whether excessive arm swing can reduce the cost of transport even further is unknown. Therefore, we tested the effects of normal and exaggerated arm swing on the cost of transport in the current study. Healthy participants (n=12) walked on a treadmill (1.25 m/s) in seven trials with different arm swing amplitudes (in-phase, passive restricted, active restricted, normal, three gradations of extra arm swing), while metabolic energy cost and the vertical angular momentum (VAM) and ground reaction moment (GRM) were measured.In general, VAM and GRM decreased as arm swing amplitude was increased, except for in the largest arm swing amplitude condition. The decreases in VAM and GRM were accompanied by a decrease in cost of transport from in-phase walking (negative amplitude) up to a slightly increased arm swing (non-significant difference compared to normal arm swing). The most excessive arm swings led to an increase in the cost of transport, most likely due to the cost of swinging the arms. In conclusion, increasing arm swing amplitude leads to a reduction in vertical angular moment and ground reaction moments, but it does not lead to a reduction in cost of transport for the most excessive arm swing amplitudes. Normal or slightly increased arm swing amplitude appears to be optimal in terms of cost of transport in young and healthy individuals.SUMMARY STATEMENTExcessive arm swing reduces the vertical angular momentum and ground reaction moment, but not necessarily the energetic cost of transport.

scholarly journals Kinematic Analysis of Lower Limb Joint Asymmetry during Gait in People with Multiple Sclerosis

Symmetry ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 598
Author(s):  
Massimiliano Pau ◽  
Bruno Leban ◽  
Michela Deidda ◽  
Federica Putzolu ◽  
Micaela Porta ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
Lower Limb ◽  
Sagittal Plane ◽  
Cross Sectional Study ◽  
Camera Motion ◽  
Cross Sectional ◽  
Temporal Parameters ◽  
Wide Range ◽  
Edss Score ◽  
Spatio Temporal

The majority of people with Multiple Sclerosis (pwMS), report lower limb motor dysfunctions, which may relevantly affect postural control, gait and a wide range of activities of daily living. While it is quite common to observe a different impact of the disease on the two limbs (i.e., one of them is more affected), less clear are the effects of such asymmetry on gait performance. The present retrospective cross-sectional study aimed to characterize the magnitude of interlimb asymmetry in pwMS, particularly as regards the joint kinematics, using parameters derived from angle-angle diagrams. To this end, we analyzed gait patterns of 101 pwMS (55 women, 46 men, mean age 46.3, average Expanded Disability Status Scale (EDSS) score 3.5, range 1–6.5) and 81 unaffected individuals age- and sex-matched who underwent 3D computerized gait analysis carried out using an eight-camera motion capture system. Spatio-temporal parameters and kinematics in the sagittal plane at hip, knee and ankle joints were considered for the analysis. The angular trends of left and right sides were processed to build synchronized angle–angle diagrams (cyclograms) for each joint, and symmetry was assessed by computing several geometrical features such as area, orientation and Trend Symmetry. Based on cyclogram orientation and Trend Symmetry, the results show that pwMS exhibit significantly greater asymmetry in all three joints with respect to unaffected individuals. In particular, orientation values were as follows: 5.1 of pwMS vs. 1.6 of unaffected individuals at hip joint, 7.0 vs. 1.5 at knee and 6.4 vs. 3.0 at ankle (p < 0.001 in all cases), while for Trend Symmetry we obtained at hip 1.7 of pwMS vs. 0.3 of unaffected individuals, 4.2 vs. 0.5 at knee and 8.5 vs. 1.5 at ankle (p < 0.001 in all cases). Moreover, the same parameters were sensitive enough to discriminate individuals of different disability levels. With few exceptions, all the calculated symmetry parameters were found significantly correlated with the main spatio-temporal parameters of gait and the EDSS score. In particular, large correlations were detected between Trend Symmetry and gait speed (with rho values in the range of –0.58 to –0.63 depending on the considered joint, p < 0.001) and between Trend Symmetry and EDSS score (rho = 0.62 to 0.69, p < 0.001). Such results suggest not only that MS is associated with significantly marked interlimb asymmetry during gait but also that such asymmetry worsens as the disease progresses and that it has a relevant impact on gait performances.

Construct Stability of C2 Replacement Strategies

2003 ◽  
Author(s):  
Christian M. Puttlitz ◽  
Robert P. Melcher ◽  
Vedat Deviren ◽  
Dezsoe Jeszenszky ◽  
Ju¨rgen Harms
Keyword(s):  
Repeated Measures ◽  
Posterior Instrumentation ◽  
Statistical Significance ◽  
Axial Rotation ◽  
Posterior Fixation ◽  
Camera Motion ◽  
Anterior Plate ◽  
Intact Specimen ◽  
Strut Graft ◽  
Significant Difference

Reconstruction of C2 after tumor destruction and resection remains a significant challenge. Most constructs utilize a strutgraft with plate or screw fixation. A novel C2 prosthesis combining a titanium mesh cage with bilateral C1 shelves and a T-plate has been used successfully in 18 patients. Supplemental posterior instrumentation includes C0-C3 or C1-C3. Biomechanical comparisons of this C2 prosthesis with traditional fixation options have not been reported. Five fresh-frozen human cadaveric cervical spines (C0-C5) were tested intact. Next, the C2 prosthesis, and strut graft and anterior plate constructs were tested with occiput-C3 and C1-C3 posterior fixation. Pure moment loads (up to 1.5 N-m) were applied in flexion and extension, lateral bending, and axial rotation. C1-C3 motion was evaluated using 3 camera motion analysis. Statistical significance was evaluated using one-way repeated measures ANOVA with Student-Newman-Keuls post hoc pairwise comparisons. All constructs provided a statistically significant decrease in motion in this C2 corpectomy model as compared to the intact condition. There was no significant difference in C1-C3 motion between the 4 constructs, regardless of whether the occiput was included in the fixation. Under these loading conditions, both the C2 prostheisis and strut-graft-plate constructs provided initial C1-C3 stability beyond that of the intact specimen. The occiput does not need to be included in the posterior instrumentation.

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