Kinesiology Commons^™

Modeling Of Legged Locomotion With A Suspended Load In The Sagittal Plane, Karna P. Potwar

Open Access Theses

Walking or running while carrying loads has always been a tedious task, more so when the loads are heavy. Such a task of carrying loads not only requires extra effort but also leads to physical pain and in some cases injury. Prior studies on human locomotion with a suspended load have used models that are restricted in their DOFs and so are not able to take into account the fore aft movement in human beings. The objective of this thesis is to model the dynamics of sagittal plane center-of-mass locomotion with a suspended load and apply findings to carrying loads …

External Work Is Deficient In Both Limbs Of Patients With Unilateral Pad, Shane R. Wurdeman, Sara A. Myers, Jason Johanning, Iraklis Pipinos, Nikolaos Stergiou

Journal Articles

External work was utilized to measure differences between the unaffected and the affected limb in patients with unilateral peripheral arterial disease compared to healthy controls. Patients with unilateral peripheral arterial disease have shown deficits in peak joint powers during walking in the unaffected and affected legs. However, no research has detailed the amount of work that is being performed by each leg compared to healthy controls even though such an analysis would provide valuable information on the energy output from the affected and the unaffected legs. Two hypotheses were tested: a) the unaffected and affected leg would perform less work …

Path Integration: Effect Of Curved Path Complexity And Sensory System On Blindfolded Walking, Panagiotis Koutakis, Mukul Mukherjee, Srikant Vallabhajosula, David J. Blanke, Nikolaos Stergiou

Journal Articles

Path integration refers to the ability to integrate continuous information of the direction and distance traveled by the system relative to the origin. Previous studies have investigated path integration through blindfolded walking along simple paths such as straight line and triangles. However, limited knowledge exists regarding the role of path complexity in path integration. Moreover, little is known about how information from different sensory input systems (like vision and proprioception) contributes to accurate path integration. The purpose of the current study was to investigate how sensory information and curved path complexity affect path integration. Forty blindfolded participants had to accurately …

Patients With Peripheral Arterial Disease Exhibit Reduced Joint Powers Compared To Velocity-Matched Controls, Shane R. Wurdeman, Panagiotis Koutakis, Sara A. Myers, Jason Johanning, Iraklis Pipinos, Nikolaos Stergiou

Journal Articles

Previous studies have shown major deficits in gait for individuals with peripheral arterial disease before and after the onset of pain. However, these studies did not have subjects ambulate at similar velocities and potential exists that the differences in joint powers may have been due to differences in walking velocity. The purpose of this study was to examine the joint moments and powers of peripheral arterial disease limbs for subjects walking at similar self-selected walking velocities as healthy controls prior to onset of any symptoms. Results revealed peripheral arterial disease patients have reduced peak hip power absorption in midstance ( …

Patients With Peripheral Arterial Disease Exhibit Reduced Joint Powers Compared To Velocity-Matched Controls, Shane Wurdeman, Panagiotis Koutakis, Sara Myers, Jason Johanning, Iraklis Pipinos, Nicholas Stergiou

Journal Articles

Previous studies have shown major deficits in gait for individuals with peripheral arterial disease before and after the onset of pain. However, these studies did not have subjects ambulate at similar velocities and potential exists that the differences in joint powers may have been due to differences in walking velocity. The purpose of this study was to examine the joint moments and powers of peripheral arterial disease limbs for subjects walking at similar self-selected walking velocities as healthy controls prior to onset of any symptoms. Results revealed peripheral arterial disease patients have reduced peak hip power absorption in midstance ( …

Pharmacological Treatment Of Intermittent Claudication Does Not Have A Significant Effect On Gait Impairments During Claudication Pain, Jenna M. Yentes, Jessie M. Huisinga, Sara A. Myers, Iraklis Pipinos, Jason Johanning, Nikolaos Stergiou

Journal Articles

Peripheral arterial disease (PAD) is a manifestation of atherosclerosis resulting in intermittent claudication (IC) or leg pain during physical activity. Two drugs (cilostazol and pentoxifylline) are approved for treatment of IC. Our previous work has reported no significant differences in gait biomechanics before and after drug interventions when PAD patients walked without pain. However, it is possible that the drugs are more efficacious during gait with pain. Our aim was to use advanced biomechanical analysis to evaluate the effectiveness of these drugs while walking with pain. Initial and absolute claudication distances, joint kinematics, torques, powers, and gait velocity during the …

Muscular Activity Characteristics Associated With Preparation For Gait Transition, Li Li, Lorna L. Ogden

Health Sciences & Kinesiology: Faculty Publications

Purpose: The purpose of this study was to investigate lower extremity neuromuscular activity patterns during gait transitions with continuously changing locomotion speeds.

Methods: Muscular activities related to gait transitions (walk to run and run to walk) induced by changing treadmill speed were compared to muscular activities during walk and run at constant speeds. All transition and constant speed conditions were conducted in similar speed range. Surface electromyographic activities of gluteus maximus (GM), rectus femoris (RF), vastus lateralis (VL), biceps femoris long head (BFL), tibialis anterior (TA), gastrocnemius (GA), and soleus (SL) were collected and analyzed. The influences of speed and …

Are Men Cheaper Than Women? Insights From Walking Economy, Nicole S. Schultz, Peter G. Weyand

International Journal of Exercise Science: Conference Proceedings

ARE MEN CHEAPER THAN WOMEN? INSIGHTS FROM WALKING ECONOMY

Nicole S. Schultz and Peter G. Weyand

Southern Methodist University, Locomotor Performance Laboratory, Department of Applied Physiology and Wellness, Dallas, TX 75205

Introduction: The metabolic energy cost of human walking has been extensively studied. However, whether men and women require the same amount of energy (per kg of body mass) to walk at the same speed or cover the same distance remains unresolved. While most predictive algorithms incorporate only body mass and walking speed, we have recently found that mass-specific walking metabolic rates are inversely related to stature. Objective: We tested …

Do Horizontal Forces Matter For Horizontal Running?, Kenneth P. Clark, Laurence J. Ryan, Peter G. Weyand

International Journal of Exercise Science: Conference Proceedings

DO HORIZONTAL FORCES MATTER FOR HORIZONTAL RUNNING?

Kenneth P. Clark, Laurence J. Ryan, and Peter G. Weyand

Southern Methodist University, Locomotor Performance Laboratory, Department of Applied Physiology and Wellness, Dallas, TX 75206

Classification of First Author: Doctoral Student

Introduction: The application of ground force is widely recognized as the critical determinant of running speed. At maximal speeds, 90-98% of the total force applied is directed vertically into the running surface while horizontal (fore-aft) contributions are relatively small. Despite their small magnitude, horizontal forces are clearly essential for balance and may be important for other reasons. However, the pattern of horizontal …

Variability Of Gait Is Dependent On Direction Of Progression: Implications For Active Control, Shane R. Wurdeman, Neil B. Huben

Journal Articles

Typical healthy walking displays greater variability in the mediolateral direction compared to the anteroposterior direction. This greater variability is thought to represent increased uncertainty in movement. As a result, it has been postulated that the mediolateral direction of gait requires more active control by the central nervous system while the anteroposterior direction is controlled through passive actions. However, this theory has only been tested on gait where progression occurs in the anteroposterior direction. Therefore, the purpose of this study was to investigate how the amount of variability is affected if progression occurs in the mediolateral direction using a lateral stepping …

An Unstable Shoe With A Rocker Bottom Redistributes External Work, Shane R. Wurdeman, Jenna M. Yentes, Neil B. Huben, Nikolaos Stergiou

Journal Articles

The purpose of this study was to examine the external work performed by individuals wearing a rocker bottom shoe compared to a standard shoe. It was hypothesized that individuals wearing a rocker bottom shoe would have changes in the amount of work over the course of contact with the ground. External work on the body’s centre of mass (BCOM) was calculated for individuals in both conditions. Comparisons for external work were done for positive and negative work for the entire stance phase as well as the initial double support, single support and terminal double support periods. The results revealed that …

Gait Variability Of Patients With Intermittent Claudication Is Similar Before And After The Onset Of Claudication Pain, Sara A. Myers, Iraklis Pipinos, Jason Johanning, Nikolaos Stergiou

Journal Articles

Background

Recent research demonstrated that intermittent claudication patients have increased gait variability prior to the onset of claudication. However, it is unknown if these patients experience additional gait adaptations after the onset of claudication. Thus, we sought to determine how gait variability is affected by claudication in an effort to contribute to improved clinical management.

Methods

Twenty-six intermittent claudication patients and 20 controls walked on a treadmill at self-selected speed; intermittent claudication patients were tested before (pain free) and after (pain) the onset of claudication. Variability of the ankle, knee, and hip joint angles was assessed using the largest Lyapunov …

Walk-Run Transition Speed And The Relevance Of Loading, Muscular Fatigue, And Human Kinematics: A Comparison Of Human Gait Patterns, Callie Elizabeth Gunderson

Boise State University Theses and Dissertations

INTRODUCTION: The walk-to-run transition (WRT) typically occurs at a preferred transition speed (PTS) of 1.9-2.1ms^-1. Previous research has focused on potential triggers for this transition such as leg length, muscular fatigue, loading rates (LR), and vertical ground reaction forces (VGRFs). Rather than focus on mechanisms responsible for the transition, the purpose of the current study was to determine if basic anthropometrics or gait characteristics are predictive of the WRT. METHODS: Thirty participants were recruited for the current study (n = 13 male, 17 female; n = 11 normal weight, n = 10 overweight, n = …

Comparative Forelimb Muscle Function In Turtles: Tests Of Environmental Variation And Neuromotor Conservation, Angela Rivera

All Dissertations

Novel locomotor functions in animals may evolve through changes in morphology, muscle activity, or a combination of both. The idea that new functions or behaviors can arise solely through changes in structure, without concurrent changes in the patterns of muscle activity that control movement of those structures, has been formalized as the `neuromotor conservation hypothesis'. In vertebrate locomotor systems, evidence for neuromotor conservation is found across transitions in terrestrial species and into fliers, but transitions in aquatic species have received little comparable study to determine if changes in morphology and muscle function were coordinated through the evolution of new locomotor …

Multiple Sclerosis Affects The Frequency Content In The Vertical Ground Reaction Forces During Walking, Shane R. Wurdeman, Jessie M. Huisinga, Mary Filipi, Nikolaos Stergiou

Journal Articles

Background: Multiple sclerosis is a progressive neurological disease that results in a high incident of gait disturbance. Exploring the frequency content of the ground reaction forces generated during walking may provide additional insights to gait in patients with multiple sclerosis that could lead to specific tools for differential diagnosis. The purpose of this study was to investigate differences in the frequency content of these forces in an effort to contribute to improved clinical management of this disease.

Methods: Eighteen patients and eighteen healthy controls walked across a 10 meter long walkway. The anterior–posterior and vertical ground reaction forces generated …

Walking Abnormalities Are Associated With Copd: An Investigation Of The Nhanes Iii Dataset, Jenna M. Yentes, Harlan Sayles, Jane Meza, David M. Mannino, Stephen I. Rennard, Nikolaos Stergiou

Journal Articles

Research on the peripheral effects of COPD has focused on physiological and structural changes. However, different from muscular weakness or decreased physical activity, mechanical abnormalities of the muscular system, e.g. walking, have yet to be investigated. Our purpose was to utilize the National Health and Nutritional Examination Survey (NHANES) dataset to determine whether walking abnormalities are associated with COPD severity. To determine if walking abnormalities were independently associated with COPD severity, our analysis aimed to investigate the association of physical activity levels with COPD severity and with walking abnormalities. The NHANES III dataset that contains data for 31,000 persons that …

Femoral Loading Mechanics In Virginia Opossums (Didelphis Virginiana): Torsion And Mediolateral Bending In Mammalian Parasagittal Locomotion, William Gosnell

All Theses

Studies of limb bone loading in terrestrial mammals have typically found anteroposterior bending to be the primary loading regime, with torsion contributing minimally. However, previous studies have focused on large, cursorial eutherian species in which the limbs are held essentially upright. Recent in vivo strain data from the Virginia opossum Didelphis virginiana, a marsupial that uses a crouched rather than upright limb posture, have indicated that its femur experiences moderate torsion during locomotion as well as strong mediolateral bending. The elevated femoral torsion and strong mediolateral bending observed in opossums (compared to other mammals) might result from external forces such …

An Investigation Of Lower-Extremity Functional Asymmetry For Non-Preferred Able-Bodied Walking Speeds, John Rice, Matthew K. Seeley

International Journal of Exercise Science

Functional asymmetry is an idea that is often used to explain documented bilateral asymmetries during able-bodied gait. Within this context, this idea suggests that the non-dominant and dominant legs, considered as whole entities, contribute asymmetrically to support and propulsion during walking. The degree of functional asymmetry may depend upon walking speed. The purpose of this study was to better understand a potential relationship between functional asymmetry and walking speed. We measured bilateral ground reaction forces (GRF) for 20 healthy subjects who walked at nine different speeds: preferred, +10%, +20%, +30%, +40%, -10%, -20%, -30%, and -40%. Contribution to support was …

Treatment With Pharmacological Agents In Peripheral Arterial Disease Patients Does Not Result In Biomechanical Gait Changes, Jessie M. Huisinga, Iraklis Pipinos, Nikolaos Stergiou, Jason Johanning

Journal Articles

Pharmacological treatment has been used to alleviate the claudication symptoms and improve walking performance in peripheral arterial disease (PAD) patients. However, the effects of claudication treatments on gait mechanics have not been objectively indentified with biomechanical techniques. For this study, 20 PAD patients were assigned to take either pentoxifylline (n = 11) or cilostazol (n = 9), the two FDA-approved pharmacological therapies used to treat intermittent claudication symptoms. All patients completed a gait evaluation protocol that involved the acquisition of kinematic and kinetic gait data before use of the medication and after 12 weeks of treatment. Results showed that treatment …

The Effect Of Virtual Reality On Gait Variability, Dimitrios Kastavelis, Mukul Mukherjee, Leslie M. Decker, Nikolaos Stergiou

Journal Articles

Optic Flow (OF) plays an important role in human locomotion and manipulation of OF characteristics can cause changes in locomotion patterns. The purpose of the study was to investigate the effect of the velocity of optic flow on the amount and structure of gait variability. Each subject underwent four conditions of treadmill walking at their self-selected pace. In three conditions the subjects walked in an endless virtual corridor, while a fourth control condition was also included. The three virtual conditions differed in the speed of the optic flow displayed as follows – same speed (OFn), faster (OFf), and slower (OFs) …

The Effect Of Pharmacological Treatment On Gait Biomechanics In Peripheral Arterial Disease Patients, Jessie M. Huisinga, Iraklis Pipinos, Jason Johanning, Nikolaos Stergiou

Journal Articles

Background: Pharmacological treatment has been advocated as a first line therapy for Peripheral Arterial Disease (PAD) patients suffering from intermittent claudication. Previous studies document the ability of pharmacological treatment to increase walking distances. However, the effect of pharmacological treatment on gait biomechanics in PAD patients has not been objectively evaluated as is common with other gait abnormalities. Methods: Sixteen patients were prescribed an FDA approved drug (Pentoxifylline or Cilostazol) for the treatment of symptomatic PAD. Patients underwent baseline gait testing prior to medication use which consisted of acquisition of ground reaction forces and kinematics while walking in a pain free …

Hydrodynamic Fin Function Of Brief Squid, Lolliguncula Brevis, William J. Stewart, Ian K. Bartol, Paul S. Krueger

Biological Sciences Faculty Publications

Although the pulsed jet is often considered the foundation of a squid's locomotive system, the lateral fins also probably play an important role in swimming, potentially providing thrust, lift and dynamic stability as needed. Fin morphology and movement vary greatly among squid species, but the locomotive role of the fins is not well understood. To begin to elucidate the locomotive role of the fins in squids, fin hydrodynamics were studied in the brief squid Lolliguncula brevis, a species that exhibits a wide range of fin movements depending on swimming speed. Individual squid were trained to swim in both the …

Variability Of Lower Extremity Joint Kinematics During Backward Walking In A Virtual Environment, Dimitrios Kastavelis, Mukul Mukherjee, Leslie M. Decker, Nikolaos Stergiou

Journal Articles

Backward walking (BW) shows significant differences with forward walking (FW) and these differences are potentially useful in rehabilitation. However the lack of visual cues makes BW risky. The purpose of this study was to investigate the effect of visual cues provided by a virtual environment on FW and BW on gait variability. Each subject underwent four conditions of treadmill walking at self-selected pace. The subjects walked backwards in three conditions and forwards in the fourth condition. A virtual corridor was displayed to the subjects in the FW condition (forward optic flow) and two of the backward conditions (forward and backward …

Joint Torques And Powers Are Reduced During Ambulation For Both Limbs In Patients With Unilateral Claudication, Panagiotis Koutakis, Iraklis Pipinos, Sara A. Myers, Nikolaos Stergiou, Thomas G. Lynch, Jason Johanning

Journal Articles

Objectives: Symptomatic peripheral arterial disease (PAD) results in significant gait impairment. In an attempt to fully delineate and quantify these gait alterations, we analyzed joint kinematics, torques (rotational forces), and powers (rotational forces times angular velocity) in patients with PAD with unilateral claudication for both the affected and nonaffected legs.

Methods: Twelve patients with unilateral PAD (age, 61.69 ± 10.53 years, ankle-brachial index [ABI]: affected limb 0.59 ± 0.25; nonaffected limb 0.93 ± 0.12) and 10 healthy controls (age, 67.23 ± 12.67 years, ABI >1.0 all subjects) walked over a force platform to acquire gait kinetics, while joint kinematics were …

Nonlinear Analysis Of Ambulatory Activity Patterns In Community-Dwelling Older Adults, James T. Cavanaugh, Naomi Kochi, Nikolaos Stergiou

Journal Articles

Background The natural ambulatory activity patterns of older adults are not well understood. User-worn monitors illuminate patterns of ambulatory activity and generate data suitable for analysis using measures derived from nonlinear dynamics.

MethodsAmbulatory activity data were collected continuously from 157 community-dwelling older adults for 2 weeks. Participants were separated post hoc into groups based on the mean number of steps per day: highly active (steps ≥ 10,000), moderately active (5,000 ≤ steps < 10,000 steps), and inactive (steps

Results All groups displayed patterns of fluctuating step count values containing complex temporal structure. DFA, ER, and ApEn parameter values increased monotonically and significantly with increasing activity …

The Effects Of Shoe Traction And Obstacle Height On Lower Extremity Coordination Dynamics During Walking, Leslie M. Decker, Jeremy J. Houser, John M. Noble, Gregory M. Karst, Nikolaos Stergiou

Journal Articles

This study aims to investigate the effects of shoe traction and obstacle height on lower extremity relative phase dynamics (analysis of intralimb coordination) during walking to better understand the mechanisms employed to avoid slippage following obstacle clearance. Ten participants walked at a self-selected pace during eight conditions: four obstacle heights (0%, 10%, 20%, and 40% of limb length) while wearing two pairs of shoes (low and high traction). A coordination analysis was used and phasing relationships between lower extremity segments were examined. The results demonstrated that significant behavioral changes were elicited under varied obstacle heights and frictional conditions. Both decreasing …

Pulsed Jet Dynamics Of Squid Hatchlings At Intermediate Reynolds Numbers, Ian K. Bartol, Paul S. Krueger, William J. Stewart, Joseph T. Thompson

Biological Sciences Faculty Publications

Squid paralarvae (hatchlings) rely predominantly on a pulsed jet for locomotion, distinguishing them from the majority of aquatic locomotors at low/intermediate Reynolds numbers (Re), which employ oscillatory/undulatory modes of propulsion. Although squid paralarvae may delineate the lower size limit of biological jet propulsion, surprisingly little is known about the hydrodynamics and propulsive efficiency of paralarval jetting within the intermediate Re realm. To better understand paralarval jet dynamics, we used digital particle image velocimetry (DPIV) and high-speed video to measure bulk vortex properties ( e. g. circulation, impulse, kinetic energy) and other jet features [ e. g. average and …

Effects Of Alcohol And Training On Exercise Performance And Muscle Recovery Biochemistry In The Brown Anole (Anolis Sagrei), Maryclaire Mcgovern

Honors Theses

Contrary to previous research, training may improve exercise performance in a lizard, the brown anole. A brief, two-week training period resulted in increased performance speed and distance before exhaustion in trained lizards. Trained lizards were also able to more effectively use leg glycogen stores, however each of these improvements were not found in lizards treated with alcohol. Liver glycogen concentrations were also lower in alcohol-treated lizards, and patterns of liver glycogen concentrations during recovery indicate some hepatic lactate gluconeogenesis.

Evidence Of Self-Correcting Spiral Flows In Swimming Boxfishes, I. K. Bartol, M. S. Gordon, P. Webb, D. Weihs, M. Gharib

Biological Sciences Faculty Publications

The marine boxfishes have rigid keeled exteriors (carapaces) unlike most fishes, yet exhibit high stability, high maneuverability and relatively low drag given their large cross-sectional area. These characteristics lend themselves well to bioinspired design. Based on previous stereolithographic boxfish model experiments, it was determined that vortical flows develop around the carapace keels, producing self-correcting forces that facilitate swimming in smooth trajectories. To determine if similar self-correcting flows occur in live, actively swimming boxfishes, two species of boxfishes (Ostracion meleagris and Lactophrys triqueter) were induced to swim against currents in a water tunnel, while flows around the fishes were quantified …

Do Horizontal Propulsive Forces Influence The Nonlinear Structure Of Locomotion?, Max J. Kurz, Nikolaos Stergiou

Journal Articles

Background: Several investigations have suggested that changes in the nonlinear gait dynamics are related to the neural control of locomotion. However, no investigations have provided insight on how neural control of the locomotive pattern may be directly reflected in changes in the nonlinear gait dynamics. Our simulations with a passive dynamic walking model predicted that toe-off impulses that assist the forward motion of the center of mass influence the nonlinear gait dynamics. Here we tested this prediction in humans as they walked on the treadmill while the forward progression of the center of mass was assisted by a custom built …