Biomechanics Commons^™

Computational Approaches For Diagnosing Neurological Impairments And Restoring Functional Movement, Serhii Bahdasariants

Graduate Theses, Dissertations, and Problem Reports (ETD)

Movement is the primary means by which the nervous system converts intention into interaction with the environment. Voluntary limb motion enables standing, walking, reaching, and grasping—actions that underpin self‑care, communication, and economic participation. When diseases or injuries disrupt the pathways that couple neural commands to muscle forces—whether through cortical stroke, spinal cord injury, or peripheral nerve damage—mechanical outcomes such as weakness, loss of coordination, and ultimately reduced mobility emerge. These impairments cascade into secondary complications, increased dependence on caregivers, and diminished quality of life. Quantifying how the lesion alters the mechanics of movement is therefore essential for designing targeted interventions …

Nonan Gaitprint: An Imu Gait Database Of Healthy Young Adults, Tyler M. Wiles, Madhur Mangalam, Joel H. Sommerfeld, Seung Kyeom Kim, Kolby J. Brink, Anaëlle Charles, Alli Grunkemeyer, Marilena Kalaitzi Manifrenti, Spyridon Mastorakis, Nicholas Stergiou, Aaron Likens

Journal Articles

An ongoing thrust of research focused on human gait pertains to identifying individuals based on gait patterns. However, no existing gait database supports modeling efforts to assess gait patterns unique to individuals. Hence, we introduce the Nonlinear Analysis Core (NONAN) GaitPrint database containing whole body kinematics and foot placement during self-paced overground walking on a 200-meter looping indoor track. Noraxon Ultium MotionTM inertial measurement unit (IMU) sensors sampled the motion of 35 healthy young adults (19–35 years old; 18 men and 17 women; mean ± 1 s.d. age: 24.6 ± 2.7 years; height: 1.73 ± 0.78 m; body mass: …

A Kinematic And Emg Dataset Of Online Adjustment Of Reach-To-Grasp Movements To Visual Perturbations, Mariusz P. Furmanek, Madhur Mangalam, Matthew Yarossi, Kyle Lockwood, Eugene Tunik

Journal Articles

Control of reach-to-grasp movements for deft and robust interactions with objects requires rapid sensorimotor updating that enables online adjustments to changing external goals (e.g., perturbations or instability of objects we interact with). Rarely do we appreciate the remarkable coordination in reach-to-grasp, until control becomes impaired by neurological injuries such as stroke, neurodegenerative diseases, or even aging. Modeling online control of human reach-to-grasp movements is a challenging problem but fundamental to several domains, including behavioral and computational neuroscience, neurorehabilitation, neural prostheses, and robotics. Currently, there are no publicly available datasets that include online adjustment of reach-to-grasp movements to object perturbations. This …

Quantifying Fear Of Falling By Utilizing Objective Body Sway And Muscle Contraction Measures, Chenfan Gui

Theses & Dissertations

Fear of falling (FOF) is a psychological condition that can lead to increased morbidity and mortality in the elder population. However, the subjective and multidimensional nature of FOF resulted in the limitations of existing FOF measurements, which could influence the quality of those studies. The present study aimed to quantify FOF by using objective center of pressure (COP) trajectories and muscle contraction of the lower extremity to compensate for those limitations. Nineteen young healthy adults (24 years ± 2.47) were recruited in the present study. Subjects were required to watch three 360-degree videos, one control video and two roller coaster …

Effects Of A Dual-Task Paradigm On Tandem Gait Performance, Courtney Angela Perry

Cal Poly Humboldt theses and projects

In concussion management, a variety of cognitive and motor control tests, like the tandem gait, have been used for assessing the presence of a concussion injury at the sideline and through recovery. More recently, research suggests that introducing a secondary cognitive retention task during tandem gait (i.e., dual task) may provide a better assessment of concussion. The purpose of this study was to determine if a tandem gait test paired with a 6-digit retention is a valid and reliable tool. Participants completed three trials of both the single-task (ST) and dual-task (DT) tandem gait tests, and their average (MEAN) and …

Geometric Visual Illusion Effects On Visual Perception And Visuomotor Control: Emphasis On The Vertical-Horizontal Illusion, Shijun Yan

LSU Doctoral Dissertations

The focus of this dissertation was to explore the effects of potential vertical-horizontal (V-H) illusory influences on perceptuomotor control. As part of this focus, we examined the potential use of separate cortical visual streams: the ventral visual stream for perception and the dorsal visual stream for action. Three studies were conducted to determine the effects of the V-H illusion influences on length estimations using upper limb point-to-point movements and lower limb stepping movements, involving various illusory configurations, movement directions, gaze directions. After a short introduction (Chapter 1) and a more detailed review of existing literature (Chapter 2), we present manuscripts …

Neuromechanical Tuning For Arm Motor Control, Russell Lee Hardesty Jr

Graduate Theses, Dissertations, and Problem Reports (ETD)

Movement is a fundamental behavior that allows us to interact with the external world. Its importance to human health is most evident when it becomes impaired due to disease or injury. Physical and occupational rehabilitation remains the most common treatment for these types of disorders. Although therapeutic interventions may improve motor function, residual deficits are common for many pathologies, such as stroke. The development of novel therapeutics is dependent upon a better understanding of the underlying mechanisms that govern movement. Movement of the human body adheres to the principles of classic Newtonian mechanics. However, due to the inherent complexity of …

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

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 …

Determining The Effectiveness Of Core Strengthening Exercise Therapies In Treating Nonspecific Low Back Pain: A Critically Appraised Topic, Amanda King, Andrea Cripps

Journal of Sports Medicine and Allied Health Sciences: Official Journal of the Ohio Athletic Trainers Association

CLINICAL SCENARIO: Nonspecific low back pain is a condition which impacts athletes of all calibers and sports. It has been found that a total of 68% of top athletes from multiple sports have been affected by nonspecific low back pain at some point in their career. Clinicians have discussed that tight hamstrings and weak core muscles are a major cause of nonspecific low back pain. A myriad of program exist to reduce nonspecific low back pain caused from hamstring tightness, however a standardized rehabilitation protocol for strengthening the core muscles to reduce nonspecific low back pain is not as well …

Effects Of Attentional Focus Cues On Soccer Trap Kinematics And Performance, Ladule Lako Losarah

Theses and Dissertations

The primary purpose of this research was to assess how the kinematic performance of an inside of the foot soccer ball control movement changed with an internal, external, or holistic attentional focus coaching cue. The researchers used pendulum catapult to launch a soccer ball from 8.5 meters at the participant. Ten female active NCAA division 1 soccer players received one of three cues, or no cue, and then had five trials to control the ball onto an artificial turf mat to score 1-3 points depending on where the ball landed. Participants completed a manipulation check survey to ascertain the efficacy …

When Coordinating Finger Tapping To A Variable Beat The Variability Scaling Structure Of The Movement And The Cortical Bold Signal Are Both Entrained To The Auditory Stimuli, Steven Harrison, Michael Hough, Kendra K. Schmid, Boman Groff, Nicholas Stergiou

Journal Articles

Rhythmic actions are characterizable as a repeating invariant pattern of movement together with variability taking the form of cycle-to-cycle fluctuations. Variability in behavioral measures is atypically random, and often exhibits serial temporal dependencies and statistical self-similarity in the scaling of variability magnitudes across timescales. Self-similar (i.e. fractal) variability scaling is evident in measures of both brain and behavior. Variability scaling structure can be quantified via the scaling exponent (α) from detrended fluctuation analysis (DFA). Here we study the task of coordinating thumb-finger tapping to the beats of constructed auditory stimuli. We test the hypothesis that variability scaling evident …

Physiological Tremor In Handgun Aiming And Shooting Tasks, Kyle J. Kellran

Human Movement Studies & Special Education Theses & Dissertations

When holding an outstretched limb or aiming at a target, humans produce small involuntary fluctuations that may hamper performance. Current strategies for minimizing the impact of tremulous oscillations predominantly include both extrinsic and intrinsic support. The aim of the current dissertation is to better understand the parameters of physiological tremor associated with handgun aiming with the end goal of improving shooting accuracy. Experiment 1 focused on handgun aiming and the influence of different arm posture adopted during aiming. Experiment 2 expanded upon the findings of experiment 1 by comparing tremor during finger pointing, handgun aiming, and handgun shooting. Experiment 3 …

Coactivation Index Of Children With Congenital Upper Limb Reduction Deficiencies Before And After Using A Wristdriven 3d Printed Partial Hand Prosthesis, Jorge Zuniga, Dimitrios Kastavelis, Jean Peck, Rakesh Srivastava, James E. Pierce, Drew R. Dudley, David A. Salazar, Keaton J. Young, Brian A. Knarr

Journal Articles

Background: Co-contraction is the simultaneous activation of agonist and antagonist muscles that produces forces around a joint. It is unknown if the use of a wrist-driven 3D printed transitional prostheses has any influence on the neuromuscular motor control strategies of the affected hand of children with unilateral upper-limb reduction deficiencies. Thus, the purpose of the current investigation was to examine the coactivation index (CI) of children with congenital upper-limb reduction deficiencies before and after 6 months of using a wrist-driven 3D printed partial hand prosthesis.

Methods: Electromyographic activity of wrist flexors and extensors (flexor carpi ulnaris and extensor …

Reduced Vertical Displacement Of The Center Of Mass Is Not Accompanied By Reduced Oxygen Uptake During Walking, Shane R. Wurdeman, Peter C. Raffalt, Nicholas Stergiou

Journal Articles

The six determinants of gait proposed that the goal of gait is to minimize vertical displacement of the body’s center of mass (CoM) with the objective to optimize energy expenditure. On the contrary, recent investigations suggest that reduced vertical displacement leads to an increase in energy expenditure. However, these investigations had the included subjects deliberately changing their gait, which could bias the endpoint measures. The present study investigated the effect of reduced vertical displacement of the CoM on oxygen uptake and walking economy without imposing altered gait patterns. This was accomplished by having subjects walk on a curved treadmill and …

Functional Changes Through The Usage Of 3d-Printed Transitional Prostheses In Children, Jorge Zuniga, Jean Peck, Rakesh Srivastava, James E. Pierce, Drew Dudley, Nicholas T. Than, Nicholas Stergiou

Journal Articles

Introduction: There is limited knowledge on the use of 3 D-printed transitional prostheses, as they relate to changes in function and strength. Therefore, the purpose of this study was to identify functional and strength changes after usage of 3 D-printed transitional prostheses for multiple weeks for children with upper-limb differences.

Materials and methods: Gross manual dexterity was assessed using the Box and Block Test and wrist strength was measured using a dynamometer. This testing was conducted before and after a period of 24 ± 2.61 weeks of using a 3 D-printed transitional prosthesis. The 11 children (five girls and six …

Determining The Effectiveness Of Core Strengthening Exercise Therapies In Treating Nonspecific Low Back Pain: A Critically Appraised Topic, Amanda King, Andrea Cripps

Journal of Sports Medicine and Allied Health Sciences: Official Journal of the Ohio Athletic Trainers Association

In Volume 3, Issue 1 of the JSMAHS you will find Professionals abstracts, as well Under Graduate student research abstracts, case reports, and critically appraised topics.

Thank you for viewing this 3^rd Annual OATA Special Edition.

Dynamic Perception Of Dynamic Affordances: Walking On A Ship At Sea, Hannah Walter, Jeffrey B. Wagman, Nicholas Stergiou, Nurtekin Erkmen, Thomas A. Stoffregen

Journal Articles

Motion of the surface of the sea (waves, and swell) causes oscillatory motion of ships at sea. Generally, ships are longer than they are wide. One consequence of this structural difference is that oscillatory ship motion typically will be greater in roll (i.e., the ship rolling from side to side) than in pitch (i.e., the bow and stern rising and falling). For persons on ships at sea, affordances for walking on the open deck should be differentially influenced by ship motion in roll and pitch. Specifically, the minimum width of a walkable path should be greater when walking along the …

Freezing Of Gait Associated With A Corpus Callosum Lesion, Marian L. Dale, Martina Mancini, Carolin Curtze, Fay B. Horak, Brett W. Fling

Journal Articles

Freezing of gait (FoG) is a debilitating feature of Parkinson’s disease and other parkinsonian disorders. This case demonstrates a variant of freezing of gait in a non-parkinsonian patient with a lesion of the anterior corpus callosum. The freezing improved with increased upper extremity sensory input, suggesting that compensatory circuits for use of somatosensory inputs from the arms to postural and locomotor centers were intact.

Optic Flow Improves Adaptability Of Spatiotemporal Characteristics During Split-Belt Locomotor Adaptation With Tactile Stimulation, Diderik Jan Anthony Eikema, Jung Chien, Nicholas Stergiou, Sara Myers, Melissa Scott-Pandorf, Jacob J. Bloomberg, Mukul Mukherjee

Journal Articles

Human locomotor adaptation requires feedback and feed-forward control processes to maintain an appropriate walking pattern. Adaptation may require the use of visual and proprioceptive input to decode altered movement dynamics and generate an appropriate response. After a person transfers from an extreme sensory environment and back, as astronauts do when they return from spaceflight, the prolonged period required for re-adaptation can pose a significant burden. In our previous paper, we showed that plantar tactile vibration during a split-belt adaptation task did not interfere with the treadmill adaptation however, larger overground transfer effects with a slower decay resulted. Such effects, in …

The Influence Of Auditory-Motor Coupling On Fractal Dynamics In Human Gait, Nathaniel Hunt, Denise Mcgrath, Nikolaos Stergiou

Journal Articles

Humans exhibit an innate ability to synchronize their movements to music. The field of gait rehabilitation has sought to capitalize on this phenomenon by invoking patients to walk in time to rhythmic auditory cues with a view to improving pathological gait. However, the temporal structure of the auditory cue, and hence the temporal structure of the target behavior has not been sufficiently explored. This study reveals the plasticity of auditory-motor coupling in human walking in relation to ‘complex’ auditory cues. The authors demonstrate that auditory-motor coupling can be driven by different coloured auditory noise signals (e.g. white, brown), shifting the …

Temporal Structure Of Variability Reveals Similar Control Mechanisms During Lateral Stepping And Forward Walking, Shane R. Wurdeman, Nikolaos Stergiou

Journal Articles

Previous research exploring a lateral stepping gait utilized amount of variability (i.e. coefficient of variation) in the medial-lateral (ML) and anterior-posterior (AP) direction to propose that the central nervous system’s active control over gait in any direction is dependent on the direction of progression. This study sought to further explore this notion through the study of the temporal structure of variability which is reflective of the neuromuscular system’s organization of the movement over time. The largest Lyapunov exponent (LyE) of the reconstructed attractors for the foot’s movement in the AP and ML was calculated. Results revealed that despite the obvious …

Motor Control Of The Lower Extremity Musculature In Children With Cerebral Palsy, David J. Arpin, Wayne A. Stuberg, Nick Stergiou, Max J. Kurz

Journal Articles

The aim of this investigation was to quantify the differences in torque steadiness and variability of the muscular control in children with cerebral palsy (CP) and typically developing (TD) children. Fifteen children with CP (age = 14.2 ± 0.7 years) that had a Gross Motor Function Classification System (GMFCS) score of I-III and 15 age and gender matched TD children (age = 14.1 ± 0.7 years) participated in this investigation. The participants performed submaximal steady-state isometric contractions with the ankle, knee, and hip while surface electromyography (sEMG) was recorded. An isokinetic dynamometer was used to measure the steady-state isometric torques …

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 …

Supervised Resistance Training Results In Changes In Postural Control In Patients With Multiple Sclerosis, Jessie M. Huisinga, Mary Filipi, Nikolaos Stergiou

Journal Articles

Postural disturbances are one of the first reported symptoms in patients with Multiple Sclerosis (MS). The purpose of this study was to investigate the effect of supervised resistance training on postural control in MS patients. Postural control was assessed using amount of sway variability [Root Mean Square (RMS)] and temporal structure of sway variability [Lyapunov Exponent (LyE)] from 15 MS patients. Posture was evaluated before and after completion of three months of resistance training. There were significant differences between MS patients pretraining and healthy controls for both LyE (p = .000) and RMS (p = .002), but no differences between …

From The W-Method To The Canonical-Dissipative Method For Studying Uni-Manual Rhythmic Behavior, Dobromir Dotov, Till D. Frank

Journal Articles

A novel method for the analysis of repetitive limb behavior oscillation is presented. It is based on a model used to account for self-sustained limit cycles that involve energy pumping compensating for dissipative processes. The experiment involved a uni-manual pendulum swinging task paced at five frequencies. The median frequency corresponded to the resonant one for the chosen pendulum and hand parameters. We applied the model-based analysis to explore the relationship between behavioral observables and model parameters not available from previous methods. Oscillation amplitude and energy, and motor variability were the behavioral observables we focused on while energy pumping, attractor strength, …

Use Of Information Entropy Measures Of Sitting Postural Sway To Quantify Developmental Delay In Infants, Joan E. Deffeyes, Regina T. Harbourne, Stacey L. Dejong, Anastasia Kyvelidou, Wayne A. Stuberg, Nikolaos Stergiou

Journal Articles

Background: By quantifying the information entropy of postural sway data, the complexity of the postural movement of different populations can be assessed, giving insight into pathologic motor control functioning.

Methods: In this study, developmental delay of motor control function in infants was assessed by analysis of sitting postural sway data acquired from force plate center of pressure measurements. Two types of entropy measures were used: symbolic entropy, including a new asymmetric symbolic entropy measure, and approximate entropy, a more widely used entropy measure. For each method of analysis, parameters were adjusted to optimize the separation of the results from the …

In Situ Muscle Power Differs Without Varying In Vitro Mechanical Properties In Two Insect Leg Muscles Innervated By The Same Motor Neuron, Anna N. Ahn, Kenneth Meijer, Robert J. Full

All HMC Faculty Publications and Research

The mechanical behavior of muscle during locomotion is often predicted by its anatomy, kinematics, activation pattern and contractile properties. The neuromuscular design of the cockroach leg provides a model system to examine these assumptions, because a single motor neuron innervates two extensor muscles operating at a single joint. Comparisons of the in situ measurements under in vivo running conditions of muscle 178 to a previously examined muscle (179) demonstrate that the same inputs (e.g. neural signal and kinematics) can result in different mechanical outputs. The same neural signal and kinematics, as determined during running, can result in different mechanical functions, …