Kinesiology Commons^™

Changes In Human Walking Dynamics Induced By Uneven Terrain Are Reduced With Ongoing Exposure, But A Higher Variability Persists, Jenny A. Kent, Joel H. Sommerfeld, Nicholas Stergiou

Journal Articles

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During walking, uneven terrain alters the action of the ground reaction force from stride to stride. The extent to which such environmental inconsistencies are withstood may be revealed by the regulation of whole-body angular momentum (L) during walking. L quantifies the balance of momenta of the body segments (thigh, trunk, etc.) about their combined center of mass, and remains close to zero during level walking. A failure to constrain L has been linked to falls. The aim of this study was to explore the ability of young adults to orchestrate their movement on uneven terrain, illustrated by the …

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Abstract 482: Differences In Ground Reaction Forces And Chest Compression Release Velocity In Professional And Lay Rescuers With And Without The Use Of Real-Time Cpr Feedback, Lyra Clark, Ben Senderling, Jeff R. Gould, Chris Kaufman, Nicholas Stergiou

Journal Articles

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Purpose: Chest compression release velocity (CCRV) has been associated with survival and favorable neurological outcome after cardiac resuscitation. Both complete chest release and high CCRV contribute to improved venous return during CPR. Differences in compression forces delivered by professional and lay rescuers are reported, which may contribute to differences in CCRV. The aim of this pilot study was to investigate differences in ground reaction force (GRF) and CCRV between professional and lay rescuers during CPR performed on a manikin with and without real-time feedback.

Methods: Professional (n = 5) and lay rescuers (n = 11) performed two minutes of continuous …

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Effect Of Sampling Frequency On Fractal Fluctuations During Treadmill Walking, Vivien Marmelat, Austin Duncan, Shane Meltz

Journal Articles

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The temporal dynamics of stride-to-stride fluctuations in steady-state walking reveal important information about locomotor control and can be quantified using so-called fractal analyses, notably the detrended fluctuation analysis (DFA). Gait dynamics are often collected during treadmill walking using 3-D motion capture to identify gait events from kinematic data. The sampling frequency of motion capture systems may impact the precision of event detection and consequently impact the quantification of stride-to-stride variability. This study aimed i) to determine if collecting multiple walking trials with different sampling frequency affects DFA values of spatiotemporal parameters during treadmill walking, and ii) to determine the reliability …

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Ankle And Midtarsal Joint Quasi-Stiffness During Walking With Added Mass, Andrew M. Kern, Nikolaos Papachatzis, Jeffrey M. Patterson, Dustin A. Bruening, Kota Z. Takahashi

Journal Articles

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Examination of how the ankle and midtarsal joints modulate stiffness in response to increased force demand will aid understanding of overall limb function and inform the development of bio-inspired assistive and robotic devices. The purpose of this study is to identify how ankle and midtarsal joint quasi-stiffness are affected by added body mass during over-ground walking. Healthy participants walked barefoot over-ground at 1.25 m/s wearing a weighted vest with 0%, 15% and 30% additional body mass. The effect of added mass was investigated on ankle and midtarsal joint range of motion (ROM), peak moment and quasi-stiffness. Joint quasi-stiffness was broken …

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Kinematic Differences Between Professional And Lay Rescuers With And Without The Use Of Real-Time Cpr Feedback, Lyra Clark, Ben Senderling, Jeff R. Gould, Chris Kaufman, Nicholas Stergiou

Journal Articles

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Purpose: Guideline-compliant cardiopulmonary resuscitation (CPR) performance can be achieved with training and use of real-time feedback. Kinematic differences are reported between experts and novices in various motor tasks. The aim of this pilot study was to investigate differences in kinematics between professional and lay rescuers during CPR performed on a manikin with and without feedback.

Methods: Professional (n = 5) and lay rescuers (n = 11) performed two minutes of continuous chest compressions on a manikin for two trials. Real-time CPR feedback provided by a defibrillator was disabled in the first trial and enabled in the second. CPR …

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A Low-Cost, Wireless Near-Infrared Spectroscopy Device Detects The Presence Of Lower Extremity Atherosclerosis As Measured By Computed Tomographic Angiography And Characterizes Walking Impairment In Peripheral Artery Disease, Matthew A. Fuglestad, Hernan Hernandez, Yue Gao, Henamari Ybay, Molly Schieber, Katyarina E. Brunette, Sara A. Myers, George P. Casale, Iraklis Pipinos

Journal Articles

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Background

Patients with peripheral artery disease (PAD) who experience intermittent claudication report a range of symptoms. Patients with symptoms other than classically described intermittent claudication may be at the highest risk for functional decline and mobility loss. Therefore, technologies allowing for characterization of PAD severity are desirable. Near-infrared spectroscopy (NIRS) allows for measurements of muscle heme oxygen saturation (StO2) during exercise. We hypothesized lower extremities affected by PAD would exhibit distinct NIRS profiles as measured by a low-cost, wireless NIRS device and that NIRS during exercise predicts walking limitation.

Methods

We recruited 40 patients with PAD and 10 control participants. …

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Supervised Walking Exercise Therapy Improves Gait Biomechanics In Patients With Peripheral Artery Diseas, Molly Schieber, Iraklis Pipinos, Jason M. Johanning, George P. Casale, Mark A. Williams, Holly Despiegelaere, Ben Senderling, Sara A. Myers

Journal Articles

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Objective

In patients with peripheral artery disease (PAD), supervised exercise therapy is a first line of treatment because it increases maximum walking distances comparable with surgical revascularization therapy. Little is known regarding gait biomechanics after supervised exercise therapy. This study characterized the effects of supervised exercise therapy on gait biomechanics and walking distances in claudicating patients with PAD.

Methods

Forty-seven claudicating patients with PAD underwent gait analysis before and immediately after 6 months of supervised exercise therapy. Exercise sessions consisted of a 5-minute warmup of mild walking and stretching of upper and lower leg muscles, 50 minutes of intermittent treadmill …

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Locomotor Patterns Change Over Time During Walking On An Uneven Surface, Jenny A. Kent, Joel H. Sommerfeld, Mukul Mukherjee, Kota Z. Takahashi, Nicholas Stergiou

Journal Articles

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During walking, uneven surfaces impose new demands for controlling balance and forward progression at each step. It is unknown to what extent walking may be refined given an amount of stride-to-stride unpredictability at the distal level. Here, we explored the effects of an uneven terrain surface on whole-body locomotor dynamics immediately following exposure and after a familiarization period. Eleven young, unimpaired adults walked for 12 min on flat and uneven terrain treadmills. The whole-body center of mass excursion range (COM_exc) and peak velocity (COM_vel), step length and width were estimated. On first exposure to uneven terrain, …

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The Foot And Ankle Structures Reveal Emergent Properties Analogous To Passive Springs During Human Walking, Erica Hedrick, Steven J. Stanhope, Kota Z. Takahashi

Journal Articles

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An objective understanding of human foot and ankle function can drive innovations of bio-inspired wearable devices. Specifically, knowledge regarding how mechanical force and work are produced within the human foot-ankle structures can help determine what type of materials or components are required to engineer devices. In this study, we characterized the combined functions of the foot and ankle structures during walking by synthesizing the total force, displacement, and work profiles from structures distal to the shank. Eleven healthy adults walked at four scaled speeds. We quantified the ground reaction force and center-of-pressure displacement in the shank’s coordinate system during stance …

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Alterations In Cortical Activation Among Individuals With Chronic Ankle Instability During Single-Limb Postural Control, Adam Rosen, Jennifer M. Yentes, Melanie L. Mcgrath, Arthur C. Maerlender, Sara A. Myers, Mukul Mukherjee

Journal Articles

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Context

Chronic ankle instability (CAI) is characterized by repetitive ankle sprains and perceived instability. Whereas the underlying cause of CAI is disputed, alterations in cortical motor functioning may contribute to the perceived dysfunction. Objective

To assess differences in cortical activity during single-limb stance among control, coper, and CAI groups. Design

Cross-sectional study. Setting

Biomechanics laboratory. Patients or Other Participants

A total of 31 individuals (10 men, 21 women; age = 22.3 ± 2.4 years, height = 169.6 ± 9.7 cm, mass = 70.6 ± 11.6 kg), who were classified into control (n = 13), coper (n = 7), and CAI …

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Synchronization Dynamics Modulates Stride-To-Stride Fluctuations When Walking To An Invariant But Not To A Fractal-Like Stimulus, Joao R. Vaz, Boman Groff, Douglas Rowen, Brian Knarr, Nicholas Stergiou

Journal Articles

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Walking with different types of cueing/stimulus (i.e. auditory, visual) has been shown to alter gait variability, thus emerging as an innovative therapeutical tool to restore abnormal gait variability in clinical populations. However, the majority of the research in this area has focused on auditory stimuli while visual stimuli are an understudied alternative that needs more attention, particularly due to the natural dependence on vision during walking. Furthermore, the time differences between the occurrences of the walking steps and the sensory cues, also known as asynchronies, have also received minimal attention, even though the ability to synchronize with different stimuli is …

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An Altered Spatiotemporal Gait Adjustment During A Virtual Obstacle Crossing Task In Patients With Diabetic Peripheral Neuropathy, Chun-Kai Huang, Vijay Shivaswamy, Pariwat Thaisetthawatkul, Lynn Mack, Nicholas Stergiou, Ka-Chun Siu

Journal Articles

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This study investigates spatiotemporal gait adjustments that occur while stepping over virtual obstacles during treadmill walking in people with/without diabetic peripheral neuropathy (DPN). Eleven adults with Type 2 diabetes mellitus, ten DPN, and 11 age-matched healthy adults (HTY) participated in this study. They stepped over forthcoming virtual obstacles during treadmill walking. Outcomes such as success rate, spatiotemporal gait characteristics during obstacle crossing, and correlations between these variables were evaluated. The results partially supported our hypotheses that when comparing with HTY and DM, people with DPN adopted a crossing strategy which decreased obstacle crossing success rate and maximal toe elevation, …

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Uneven Terrain Exacerbates The Deficits Of A Passive Prosthesis In The Regulation Of Whole Body Angular Momentum In Individuals With A Unilateral Transtibial Amputation, Jenny A. Kent, Kota Z. Takahashi, Nicholas Stergiou

Journal Articles

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Background

Uneven ground is a frequently encountered, yet little-studied challenge for individuals with amputation. The absence of control at the prosthetic ankle to facilitate correction for surface inconsistencies, and diminished sensory input from the extremity, add unpredictability to an already complex control problem, and leave limited means to produce appropriate corrective responses in a timely manner. Whole body angular momentum, L, and its variability across several strides may provide insight into the extent to which an individual can regulate their movement in such a context. The aim of this study was to explore L in individuals with a transtibial amputation, …

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Gait Mechanics Differences Between Healthy Controls And Patients With Peripheral Artery Disease After Adjusting For Gait Velocity, Stride Length, And Step Width, John D. Mccamley, Eric Cutler, Kendra K. Schmid, Shane R. Wurdeman, Jason Johanning, Iraklis Pipinos, Sara A. Myers

Journal Articles

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Patients with peripheral artery disease (PAD) experience significant leg dysfunction. The effects of PAD on gait include shortened steps, slower walking velocity, and altered gait kinematics and kinetics, which may confound joint torques and power measurements. Spatiotemporal parameters and joint torques and powers were calculated and compared between 20 patients with PAD and 20 healthy controls using independent t tests. Separate analysis of covariance models were used to evaluate group differences after independently adjusting for gait velocity, stride length, and step width. Compared with healthy controls, patients with PAD exhibited reduced peak extensor and flexor torques at the knee and …

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Selection Procedures For The Largest Lyapunov Exponent In Gait Biomechanics, Peter C. Raffalt, Jenny A. Kent, Shane R. Wurdeman, Nicholas Stergiou

Journal Articles

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The present study was aimed at investigating the effectiveness of the Wolf et al. (LyE_W) and Rosenstein et al. largest Lyapunov Exponent (LyE_R) algorithms to differentiate data sets with distinctly different temporal structures. The three-dimensional displacement of the sacrum was recorded from healthy subjects during walking and running at two speeds; one low speed close to the preferred walking speed and one high speed close to the preferred running speed. LyE_R and LyE_W were calculated using four different time series normalization procedures. The performance of the algorithms were evaluated based on their ability to return relative low values for slow …

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Stride-Time Variability Is Related To Sensorimotor Cortical Activation During Forward And Backward Walking, Boman Groff, Prokopios Antonellis, Kendra K. Schmid, Brian Knarr, Nicholas Stergiou

Journal Articles

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Previous research has used functional near-infrared spectroscopy (fNIRS) to show that motor areas of the cortex are activated more while walking backward compared to walking forward. It is also known that head movement creates motion artifacts in fNIRS data. The aim of this study was to investigate cortical activation during forward and backward walking, while also measuring head movement. We hypothesized that greater activation in motor areas while walking backward would be concurrent with increased head movement. Participants performed forward and backward walking on a treadmill. Participants wore motion capture markers on their head to quantify head movement and pressure …

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Walking Speed And Spatiotemporal Step Mean Measures Are Reliable During Feedback-Controlled Treadmill Walking; However, Spatiotemporal Step Variability Is Not Reliable, Casey Wiens, William Denton, Molly Schieber, Vivien Marmelat, Sara A. Myers, Jennifer M. Yentes

Journal Articles

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The purpose of the study was to compare the effects of a feedback-controlled treadmill (FeedbackTM) to a traditional fixed-speed treadmill (FixedTM) on spatiotemporal gait means, variability, and dynamics. The study also examined inter-session reliability when using the FeedbackTM. Ten young adults walked on the FeedbackTM for a 5-minute familiarization followed by a 16-minute experimental trial. They returned within one week and completed a 5-minute familiarization followed by a 16-minute experimental trial each for FeedbackTM and FixedTM conditions. Mean walking speed and step time, length, width, and speed means and coefficient of variation were calculated from all experimental conditions. Step time, …

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The Effects Of Ankle Stiffness On Mechanics And Energetics Of Walking With Added Loads: A Prosthetic Emulator Study, Erica Hedrick, Philippe Malcolm, Jason M. Wilken, Kota Z. Takahashi

Journal Articles

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Background: The human ankle joint has an influential role in the regulation of the mechanics and energetics of gait. The human ankle can modulate its joint ‘quasi-stiffness’ (ratio of plantarflexion moment to dorsiflexion displacement) in response to various locomotor tasks (e.g., load carriage). However, the direct effect of ankle stiffness on metabolic energy cost during various tasks is not fully understood. The purpose of this study was to determine how net metabolic energy cost was affected by ankle stiffness while walking under different force demands (i.e., with and without additional load).
Methods: Individuals simulated an amputation by using …

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