scholarly journals Biomechanical Control of Paretic Lower Limb During Imposed Weight Transfer in Individuals Post-Stroke

2020 ◽  
Author(s):  
Hao-Yuan Hsiao ◽  
Vicki L Gray ◽  
James Borrelli ◽  
Mark W Rogers
Keyword(s):  
Lower Extremity ◽  
Center Of Pressure ◽  
Weight Bearing ◽  
Neuromuscular Control ◽  
Step Test ◽  
Stabilization Time ◽  
Post Stroke ◽  
Paretic Limb ◽  
Four Square ◽  
Weight Transfer

Abstract Background: stroke is a leading cause of disability with associated hemiparesis resulting in difficulty bearing and transferring weight on to the paretic limb. Difficulties in weight bearing and weight transfer may result in impaired mobility and balance, increased fall risk, and decreased community engagement. Despite considerable efforts aimed at improving weight transfer after stroke, impairments in its neuromotor and biomechanical control remain poorly understood. In the present study, a novel experimental paradigm was used to characterize differences in weight transfer biomechanics in individuals with chronic stroke versus able-bodied controls. Methods: fifteen participants with stroke and fifteen age-matched able-bodied controls participated in the study. Participants stood with one foot on each of two custom built platforms. One of the platforms dropped 4.3 cm vertically to induce lateral weight transfer and weight bearing. Trials involving a drop of the platform beneath the paretic lower extremity (non-dominant limb for control) were included in the analyses. Paretic lower extremity joint kinematics, vertical ground reaction forces, and center of pressure velocity were measured. All participants completed the clinical Step Test and Four-Square Step Test. Results: reduced paretic ankle, knee, and hip joint angular displacement and velocity, delayed ankle and knee inter-joint timing, increased downward displacement of center of mass, and increased center of pressure (COP) velocity stabilization time were exhibited in the stroke group compared to the control group. In addition, paretic COP velocity stabilization time during induced weight transfer predicted Four-Square Step Test scores in individuals post-stroke. Conclusions: the induced weight transfer approach identified stroke-related abnormalities in the control of weight transfer towards the paretic limb side compared to controls. Decreased joint flexion of the paretic ankle and knee, altered inter-joint timing, and increased COP stabilization times may reflect difficulties in neuromuscular control during weight transfer following stroke. Future work will investigate the potential of improving functional weight transfer through induced weight transfer training exercise.

scholarly journals Biomechanical control of paretic lower limb during imposed weight transfer in individuals post-stroke

2020 ◽  
Vol 17 (1) ◽  
Author(s):  
Hao-Yuan Hsiao ◽  
Vicki L. Gray ◽  
James Borrelli ◽  
Mark W. Rogers
Keyword(s):  
Lower Extremity ◽  
Center Of Pressure ◽  
Weight Bearing ◽  
Neuromuscular Control ◽  
Step Test ◽  
Stabilization Time ◽  
Post Stroke ◽  
Paretic Limb ◽  
Four Square ◽  
Weight Transfer

Abstract Background Stroke is a leading cause of disability with associated hemiparesis resulting in difficulty bearing and transferring weight on to the paretic limb. Difficulties in weight bearing and weight transfer may result in impaired mobility and balance, increased fall risk, and decreased community engagement. Despite considerable efforts aimed at improving weight transfer after stroke, impairments in its neuromotor and biomechanical control remain poorly understood. In the present study, a novel experimental paradigm was used to characterize differences in weight transfer biomechanics in individuals with chronic stroke versus able-bodied controls Methods Fifteen participants with stroke and fifteen age-matched able-bodied controls participated in the study. Participants stood with one foot on each of two custom built platforms. One of the platforms dropped 4.3 cm vertically to induce lateral weight transfer and weight bearing. Trials involving a drop of the platform beneath the paretic lower extremity (non-dominant limb for control) were included in the analyses. Paretic lower extremity joint kinematics, vertical ground reaction forces, and center of pressure velocity were measured. All participants completed the clinical Step Test and Four-Square Step Test. Results Reduced paretic ankle, knee, and hip joint angular displacement and velocity, delayed ankle and knee inter-joint timing, increased downward displacement of center of mass, and increased center of pressure (COP) velocity stabilization time were exhibited in the stroke group compared to the control group. In addition, paretic COP velocity stabilization time during induced weight transfer predicted Four-Square Step Test scores in individuals post-stroke. Conclusions The induced weight transfer approach identified stroke-related abnormalities in the control of weight transfer towards the paretic limb side compared to controls. Decreased joint flexion of the paretic ankle and knee, altered inter-joint timing, and increased COP stabilization times may reflect difficulties in neuromuscular control during weight transfer following stroke. Future work will investigate the potential of improving functional weight transfer through induced weight transfer training exercise.

scholarly journals Biomechanical Control of Paretic Lower Limb During Imposed Weight Transfer in Individuals Post-Stroke

2020 ◽  
Author(s):  
Hao-Yuan Hsiao ◽  
Vicki L Gray ◽  
James Borrelli ◽  
Mark W Rogers
Keyword(s):  
Lower Limb ◽  
Center Of Pressure ◽  
Weight Bearing ◽  
Center Of Mass ◽  
Step Test ◽  
Control Group ◽  
Post Stroke ◽  
Paretic Limb ◽  
Four Square ◽  
Weight Transfer

Abstract Background: stroke is a leading cause of disability with associated hemiparesis resulting in difficulty bearing and transferring weight on to the paretic limb. Difficulties in weight bearing and weight transfer may result in impaired mobility and balance, increased fall risk, and decreased community engagement. Despite considerable efforts aimed at improving weight transfer after stroke, impairments in its neuromotor and biomechanical control remain poorly understood. In the present study, a novel experimental paradigm was used to characterize differences in weight transfer biomechanics in individuals with chronic stroke versus able-bodied controls. Methods: fifteen participants with stroke and fifteen age-matched able-bodied controls participated in the study. Participants stood with one foot on each of two custom built platforms. One of the platforms dropped 4.3 cm vertically to induce lateral weight transfer and weight bearing. Paretic lower extremity joint kinematics, vertical ground reaction forces, and center of pressure velocity were measured. All participants completed the clinical Step Test and Four-Square Step Test. Results: reduced paretic ankle, knee, and hip joint angular displacement and velocity, delayed ankle and knee inter-joint timing, and altered center of pressure (COP) and center of mass control were exhibited in the stroke group compared to the control group. In addition, paretic COP velocity stabilization time during induced weight transfer predicted Four-Square Step Test scores in individuals post-stroke. Conclusions: the induced weight transfer approach identified stroke-related abnormalities in the control of weight transfer towards the paretic limb side compared to controls. Decreased joint flexion of the paretic ankle and knee, altered inter-joint timing, and altered COP and center of mass control appear to limit rapid lower limb loading ability. Future work will investigate the potential of improving functional weight transfer through induced weight transfer training exercise.

scholarly journals Biomechanical Control of Paretic Lower Limb During Imposed Weight Transfer in Individuals Post-Stroke

2020 ◽  
Author(s):  
Hao-Yuan Hsiao ◽  
Vicki Gray ◽  
James Borrelli ◽  
Mark W Rogers
Keyword(s):  
Sagittal Plane ◽  
Center Of Pressure ◽  
Angular Displacement ◽  
Weight Bearing ◽  
Step Test ◽  
Control Group ◽  
Lateral Direction ◽  
Post Stroke ◽  
Four Square ◽  
Weight Transfer

Abstract Background: stroke is a leading cause of disability with associated hemiparesis resulting in difficulty bearing and transferring weight on to the paretic limb. Difficulties in weight bearing and weight transfer may result in impaired mobility and balance, increased fall risk, and decreased community engagement. Despite considerable efforts aimed at improving weight transfer after stroke, impairments in its neuromotor and biomechanical control remain poorly understood. In the present study, a novel experimental paradigm was used to characterize differences in weight transfer biomechanics in individuals with chronic stroke versus able-bodied controls. Methods: fifteen participants with stroke and fifteen age-matched able-bodied controls participated in the study. Participants stood with one foot on each of two custom built platforms. One of the platforms dropped 4.3 cm vertically to induce lateral weight transfer and weight bearing. Sagittal plane kinematics, vertical ground reaction forces, and center of pressure velocity were measured. All participants completed the clinical Step Test and Four-Square Step Test. Results: reduced ankle and knee joint angular displacement and velocity, delayed inter-joint timing, and altered center of pressure control (COP) were exhibited in the stroke group compared to the control group. In addition, increased COP velocity stabilization time in the medial-lateral direction during induced weight transfer predicted Step Test scores in individuals post-stroke. Conclusions: the induced weight transfer paradigm characterized the stroke-related abnormalities in the control of weight transfer compared to controls. Decreased joint flexion of the ankle and knee, altered inter-joint timing, and altered COP control appear to be related to limitations during gait. Future work will investigate the potential of improving functional weight transfer through induced weight transfer training exercise.

scholarly journals Measurement of Paretic–Lower-Extremity Loading and Weight Transfer After Stroke

2009 ◽  
Vol 89 (7) ◽  
pp. 653-664 ◽  
Author(s):  
Vicki Stemmons Mercer ◽  
Janet Kues Freburger ◽  
Shuo-Hsiu Chang ◽  
Jama L. Purser
Keyword(s):  
Lower Extremity ◽  
Convergent Validity ◽  
Weight Bearing ◽  
Motor Impairment ◽  
Stroke Recovery ◽  
Step Test ◽  
Paretic Limb ◽  
Limb Loading ◽  
Clinical Measures ◽  
Weight Transfer

Background Weight bearing through, or “loading” of, the paretic lower extremity and transfer of weight from one lower extremity to the other are important impairment-level goals of stroke rehabilitation. Improvements in these limb-loading and weight-transfer abilities have been shown to relate to improved performance of many functional activities. Unfortunately, valid and practical clinical measures of paretic–lower-extremity loading and weight transfer have not been identified. Objective The purpose of this study was to assess convergent validity of the Step Test (ST) and the knee extension component of the Upright Motor Control Test (UMCe) as measures of paretic-limb loading and of the Repetitive Reach Test (RR) as a measure of weight transfer in the first 6 months after stroke. Design This was a prospective cohort study of 33 adults with lower-extremity motor impairment following unilateral, noncerebellar stroke. Participants were tested one time per month from 1 to 6 months poststroke. Results Scores on the ST (performed with the nonparetic leg as the stepping leg) and UMCe were positively correlated with peak vertical ground reaction forces (GRFs) beneath the paretic limb during functional tasks (R2=.35–.76 for the ST, pseudo R2=.21–.34 for the UMCe). Scores on the RR were positively correlated with change in vertical GRF beneath the paretic limb during the diagonal reach task (R2=.45) and with weight-transfer time during stepping with the nonparetic limb (R2=.15). Conclusions The ST, performed with the nonparetic leg as the stepping leg, is a valid measure of paretic-limb loading during stroke recovery. Of the clinical measures tested, the ST correlated most strongly with the force platform measures.

scholarly journals Lower Extremity Neuromuscular Control Immediately After Fatiguing Hip-Abduction Exercise

2011 ◽  
Vol 46 (6) ◽  
pp. 607-614 ◽  
Author(s):  
Kelly L. McMullen ◽  
Nicole L. Cosby ◽  
Jay Hertel ◽  
Christopher D. Ingersoll ◽  
Joseph M. Hart
Keyword(s):  
Lower Extremity ◽  
Postural Control ◽  
Center Of Pressure ◽  
Neuromuscular Control ◽  
Lower Extremity Injury ◽  
Median Frequency ◽  
Men And Women ◽  
Hip Abduction ◽  
Quality Of Movement

Context: Fatigue of the gluteus medius (GMed) muscle might be associated with decreases in postural control due to insufficient pelvic stabilization. Men and women might have different muscular recruitment patterns in response to GMed fatigue. Objective: To compare postural control and quality of movement between men and women after a fatiguing hip-abduction exercise. Design: Descriptive laboratory study. Setting: Controlled laboratory. Patients or Other Participants: Eighteen men (age = 22 ± 3.64 years, height = 183.37 ± 8.30 cm, mass = 87.02 ±12.53 kg) and 18 women (age = 22 ± 3.14, height = 167.65 ± 5.80 cm, mass = 66.64 ± 10.49 kg) with no history of low back or lower extremity injury participated in our study. Intervention(s): Participants followed a fatiguing protocol that involved a side-lying hip-abduction exercise performed until a 15% shift in electromyographic median frequency of the GMed was reached. Main Outcome Measure(s): Baseline and postfatigue measurements of single-leg static balance, dynamic balance, and quality of movement assessed with center-of-pressure measurements, the Star Excursion Balance Test, and lateral step-down test, respectively, were recorded for the dominant lower extremity (as identified by the participant). Results: We observed no differences in balance deficits between sexes (P > .05); however, we found main effects for time with all of our postfatigue outcome measures (P ≤ .05). Conclusions: Our findings suggest that postural control and quality of movement were affected negatively after a GMed-fatiguing exercise. At similar levels of local muscle fatigue, men and women had similar measurements of postural control.

scholarly journals Factors associated with dynamic balance in people with Persistent Postural Perceptual Dizziness (PPPD): a cross-sectional study using a virtual-reality Four Square Step Test

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Moshe M. H. Aharoni ◽  
Anat V. Lubetzky ◽  
Liraz Arie ◽  
Tal Krasovsky
Keyword(s):  
Virtual Reality ◽  
Trait Anxiety ◽  
Dynamic Balance ◽  
Step Test ◽  
Simulator Sickness ◽  
Balance Confidence ◽  
Task Duration ◽  
Head Kinematics ◽  
Perceived Disability ◽  
Four Square

Abstract Background Persistent postural-perceptual dizziness (PPPD) is a condition characterized by chronic subjective dizziness and exacerbated by visual stimuli or upright movement. Typical balance tests do not replicate the environments known to increase symptoms in people with PPPD—crowded places with moving objects. Using a virtual reality system, we quantified dynamic balance in people with PPPD and healthy controls in diverse visual conditions. Methods Twenty-two individuals with PPPD and 29 controls performed a square-shaped fast walking task (Four-Square Step Test Virtual Reality—FSST-VR) using a head-mounted-display (HTC Vive) under 3 visual conditions (empty train platform; people moving; people and trains moving). Head kinematics was used to measure task duration, movement smoothness and anterior–posterior (AP) and medio-lateral (ML) ranges of movement (ROM). Heart rate (HR) was monitored using a chest-band. Participants also completed a functional mobility test (Timed-Up-and-Go; TUG) and questionnaires measuring anxiety (State-Trait Anxiety Inventory; STAI), balance confidence (Activities-Specific Balance Confidence; ABC), perceived disability (Dizziness Handicap Inventory) and simulator sickness (Simulator Sickness Questionnaire). Main effects of visual load and group and associations between performance, functional and self-reported outcomes were examined. Results State anxiety and simulator sickness did not increase following testing. AP-ROM and HR increased with high visual load in both groups (p < 0.05). There were no significant between-group differences in head kinematics. In the high visual load conditions, high trait anxiety and longer TUG duration were moderately associated with reduced AP and ML-ROM in the PPPD group and low ABC and  high perceived disability were associated with reduced AP-ROM (|r| =  0.47 to 0.53; p < 0.05). In contrast, in controls high STAI-trait, low ABC and longer TUG duration were associated with increased AP-ROM (|r| = 0.38 to 0.46; p < 0.05) and longer TUG duration was associated with increased ML-ROM (r = 0.53, p < 0.01). Conclusions FSST-VR may shed light on movement strategies in PPPD beyond task duration. While no main effect of group was observed, the distinct associations with self-reported and functional outcomes, identified using spatial head kinematics, suggest that some people with PPPD reduce head degrees of freedom when performing a dynamic balance task. This supports a potential link between spatial perception and PPPD symptomatology.

Comparing durability of water- and land-based exercise benefits among older adults in South Korea: A randomized controlled trial with 1-year follow-up

2021 ◽  
pp. 1-11
Author(s):  
Se Jun Oh ◽  
Sang Heon Lee
Keyword(s):  
Exercise Intervention ◽  
External Rotation ◽  
Short Form ◽  
Controlled Trial ◽  
Weight Bearing ◽  
Aquatic Exercise ◽  
Step Test ◽  
Sf 36 ◽  
Partial Weight

BACKGROUND: Aquatic exercise can improve strength, flexibility, and aerobic function while safely providing partial weight-bearing support through viscosity and buoyancy. OBJECTIVE: The aim of the present study was to compare the effects of water-based exercise with land-based exercise before and after a 10-week exercise intervention and again at one-year follow-up. METHODS: Eighty participants aged 65 years and older were randomly assigned to either a water- or a land-based 10-week exercise program. Assessment included the Senior Fitness Test (SFT), the Modified Falls-Efficacy Scale, and the 36-Item Short-Form Health Survey (SF-36). Hip and knee strength was also measured. All assessments were completed at three time points: pre- (T1), post- (T2), and at 1-year follow-up (T3). RESULTS: Significant differences were observed between the two groups on three parameters: the SFT timed up-and-go test; lower hip muscle strength in extension, adduction, and external rotation; and quality of life (QoL) measured by the SF-36 (p< 0.05). No significant differences were observed in the SFT chair stand test, dominant arm curl test, two-minute step test, chair sit-and-reach test, back scratch test, and Modified Falls-Efficacy Scale. CONCLUSION: Aquatic exercise provided greater improvement of physical health and QoL among older people than land-based exercise.

Sign in / Sign up

Export Citation Format

Share Document