Medicine and Health Sciences Commons^™

Spatiotemporal Gait Parameter Consistency Across Two Days Of Treadmill Walking In Stroke Survivors, Alejandro Aguirre Ramirez, Samantha N. Jeffcoat, Natalia Sanchez, Andrian Kuch

Student Scholar Symposium Abstracts and Posters

Retraining impaired gait is essential in post-stroke recovery. This project aims to determine between day variability of spatiotemporal gait measures in treadmill walking post-stroke to differentiate between changes due to the intervention and measurement errors due to between day test-retest variability. Six individuals post-stroke performed a two-minute walk test at a self-selected speed (SSS) for two consecutive days. SSS was assessed through the six-minute walk test. Reflective markers were placed on anatomical landmarks (van den Bogert et al. 2013). The heel markers were used for step detection. We calculated spatiotemporal parameters: stride length, stride time, step length, stance time, and …

Classifying Toe Walking Gait Patterns Among Children Diagnosed With Idiopathic Toe Walking Using Wearable Sensors And Machine Learning Algorithms, Rahul Soangra, Yuxin Wen, Hualin Yang, Marybeth Grant-Beuttler

Physical Therapy Faculty Articles and Research

Idiopathic toe walking (ITW) is a gait abnormality in which children’s toes touch at initial contact and demonstrate limited or no heel contact throughout the gait cycle. Toe walking results in poor balance, increased risk of falling, and developmental delays among children. Identifying toe walking steps during walking can facilitate targeted intervention among children diagnosed with ITW. With recent advances in wearable sensing, communication technologies, and machine learning, new avenues of managing toe walking behavior among children are feasible. In this study, we investigate the capabilities of Machine Learning (ML) algorithms in identifying initial foot contact (heel strike versus toe …

General Variability Leads To Specific Adaptation Toward Energy Optimal Policies, Sabrina J. Abram, Katherine L. Poggensee, Natalia Sánchez, Surabhi N. Simha, James M. Finley, Steven H. Collins, J. Maxwell Donelan

Physical Therapy Faculty Articles and Research

Our nervous systems can learn optimal control policies in response to changes to our bodies, tasks, and movement contexts. For example, humans can learn to adapt their control policy in walking contexts where the energy-optimal policy is shifted along variables such as step frequency or step width. However, it is unclear how the nervous system determines which ways to adapt its control policy. Here, we asked how human participants explore through variations in their control policy to identify more optimal policies in new contexts. We created new contexts using exoskeletons that apply assistive torques to each ankle at each walking …

Mobile Phone Sensors Can Discern Medication-Related Gait Quality Changes In Parkinson's Patients In The Home Environment, Albert Pierce, Niklas König Ignasiak, Wilford K. Eiteman-Pang, Cyril Rakovski, Vincent Berardi

Psychology Faculty Articles and Research

Patients with Parkinson's Disease (PD) experience daytime symptom fluctuations, which result in small amplitude, slow and unstable walking during times when medication attenuates. The ability to identify dysfunctional gait patterns throughout the day from raw mobile phone acceleration and gyroscope signals would allow the development of applications to provide real-time interventions to facilitate walking performance by, for example, providing external rhythmic cues. Patients (n = 20, mean Hoehn and Yahr: 2.25) had their ambulatory data recorded and were directly observed twice during one day: once after medication abstention, (OFF) and once approximately 30 min after intake of their medication …

Different Biomechanical Variables Explain Within-Subjects Versus Between-Subjects Variance In Step Length Asymmetry Post-Stroke, Natalia Sánchez, Nicolas Schweighofer, James M. Finley

Physical Therapy Faculty Articles and Research

Step length asymmetry (SLA) is common in most stroke survivors. Several studies have shown that factors such as paretic propulsion can explain between-subjects differences in SLA. However, whether the factors that account for between-subjects variance in SLA are consistent with those that account for within subjects, stride-by-stride variance in SLA has not been determined. SLA direction is heterogeneous, and different impairments likely contribute to differences in SLA direction. Here, we identified common predictors between-subjects that explain within-subjects variance in SLA using sparse partial least squares regression (sPLSR). We determined whether the SLA predictors differ based on SLA direction and whether …

Using Biofeedback To Reduce Spatiotemporal Asymmetry Impairs Dynamic Balance In People Post-Stroke, Sungwoo Park, Chang Liu, Natalia Sánchez, Julie K. Tilson, Sara J. Mulroy, James M. Finley

Physical Therapy Faculty Articles and Research

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 wholebody angular momentum during walking using a full-body marker set in a sample of 36 people with …

Effects Of Visual Referencing On Backward And Forward Treadmill Walking In Vr Environments, Rahul Soangra, Sivakumar Rajagopal

Physical Therapy Faculty Articles and Research

Backward walking is used increasingly as a rehabilitation exercise for stroke and diabetic peripheral neuropathy patients to improve strength and balance. However, it is unclear how visual referencing affects backward and forward walking. In this study, we evaluated spatiotemporal gait characteristics changes due to visual referencing while backward/forward walking. Sixteen healthy young participants were recruited in this study. All participants walked for 2 min with and without visual referencing in the virtual reality environment. While walking backward participants faced the virtual reality screen similar to forward walking, but their treadmill belt direction of movement was reversed. All participants walked at …

Mediolateral Damping Of An Overhead Body Weight Support System Assists Stability During Treadmill Walking, M. Bannwart, S. L. Bayer, Niklas König Ignasiak, M. Bolliger, G. Rauter, C. A. Easthope

Physical Therapy Faculty Articles and Research

Background

Body weight support systems with three or more degrees of freedom (3-DoF) are permissive and safe environments that provide unloading and allow unrestricted movement in any direction. This enables training of walking and balance control at an early stage in rehabilitation. Transparent systems generate a support force vector that is near vertical at all positions in the workspace to only minimally interfere with natural movement patterns. Patients with impaired balance, however, may benefit from additional mediolateral support that can be adjusted according to their capacity. An elegant solution for providing balance support might be by rendering viscous damping along …

Identification Of Functional Parameters For The Classification Of Older Female Fallers And Prediction Of ‘First-Time’ Fallers, Niklas König Ignasiak

Physical Therapy Faculty Articles and Research

Falls remain a challenge for ageing societies. Strong evidence indicates that a previous fall is the strongest single screening indicator for a subsequent fall and the need for assessing fall risk without accounting for fall history is therefore imperative. Testing in three functional domains (using a total 92 measures) were completed in 84 older women (60–85 years of age), including muscular control, standing balance, and mean and variability of gait. Participants were retrospectively classified as fallers (n = 38) or non-fallers (n = 42) and additionally in a prospective manner to identify first-time fallers (FTFs) (n = 6) within a …

Classifying Lower Extremity Muscle Fatigue During Walking Using Machine Learning And Inertial Sensors, Jian Zhang, Thurmon Lockhart, Rahul Soangra

Physical Therapy Faculty Articles and Research

Fatigue in lower extremity musculature is associated with decline in postural stability, motor performance and alters normal walking patterns in human subjects. Automated recognition of lower extremity muscle fatigue condition may be advantageous in early detection of fall and injury risks. Supervised machine learning methods such as Support Vector Machines (SVM) have been previously used for classifying healthy and pathological gait patterns and also for separating old and young gait patterns. In this study we explore the classification potential of SVM in recognition of gait patterns utilizing an inertial measurement unit associated with lower extremity muscular fatigue. Both kinematic and …

The Influence Of Hip Strength On Lower-Limb, Pelvis, And Trunk Kinematics And Coordination Patterns During Walking And Hopping In Healthy Women, Jo Armour Smith, John M. Popovich, Kornelia Kulig

Physical Therapy Faculty Articles and Research

Study Design

Cross-sectional laboratory study.

Objectives

To compare peak lower-limb, pelvis, and trunk kinematics and interjoint and intersegmental coordination in women with strong and weak hip muscle performance.

Background

Persons with lower extremity musculoskeletal disorders often demonstrate a combination of weak hip musculature and altered kinematics during weight-bearing dynamic tasks. However, the association between hip strength and kinematics independent of pathology or pain is unclear.

Methods

Peak hip extensor and abductor torques were measured in 150 healthy young women. Of these, 10 fit the criteria for the strong group and 9 for the weak group, representing those with the strongest …