Biomechanics Commons^™

Haptic Portable Robotic Device For Automated Guidewire Or Catheter Navigation In Endovascular Procedures, Vahid Mohammadi, Jason Mactaggart, Majid Jadidi, Alexey Kamenskiy

Journal Articles

Purpose

Endovascular therapy is preferred over open surgery due to its minimally invasive nature, faster recovery, and lower perioperative risk; however, fluoroscopy guided procedures are limited by radiation exposure, high equipment costs, and reliance on highly skilled operators. This study aims to develop and evaluate a lightweight, portable robotic system for autonomous guidewire navigation to improve safety, accessibility, and operator independence.

Methods

A compact 400 g robotic device was designed with millimeter scale positioning accuracy, servo current-based real-time haptic feedback, precise axial rotation, automated retraction advance control, and compatibility with standard endovascular tools. Miniature linear actuated servomotors replicate skilled manual …

University Of Nebraska At Omaha Division Of Biomechanics And Research Development Annual Report 2023-2025, Uno Biomechanics

Biomechanics Annual Report

This report contains:

A letter from the Director: Dr. Nick Stergiou

Highlights articles

Center for Cardiovascular Research in Biomechanics (CRiB) articles

The Center for Research in Human Movement Variability (MOVCENTR) articles

People of UNO Biomechanics

Student Centered articles

Education Initiative articles

Biomechanical Characterization Of Porcine Lower Limb Arteries For Preclinical Evaluation Of Peripheral Vascular Devices, Barbara Batista De Oliveira, Frazer Heinis, Anastasia Desyatova, Jason Mactaggart, Alexey Kamenskiy

Journal Articles

Purpose Peripheral artery disease (PAD) predominantly affects the lower extremities, where complex biomechanical deformations during limb flexion contribute to disease progression and treatment failure. While human and cadaver studies have characterized these deformations, preclinical device testing requires large-animal models that replicate human arterial anatomy and biomechanics. Swine are commonly used, yet their biomechanical comparability to humans remains poorly defined. Methods We performed a detailed morphometric and biomechanical analysis of the external iliac (EIA), superficial femoral (SFA), and popliteal (PA) arteries in 20 Yucatan and 16 domestic swine using computed tomography angiography. Arteries were evaluated in straight and flexed limb postures …

Chitosan Nanofibrous Dressing Increased Angiogenesis And Anti-Inflammatory Response In An Acute Wound Model In Rats: A Comparative Study, Yury Salkovskiy, Mahboubeh Ghanbari, Carlos P Jara, Sara Cartwright, Pinaki Mondal, Colman Freel, Sayed Ahmadreza Razian, Jason Mactaggart, Mark A. Carlson

Journal Articles

Purpose

Chitosan-based materials are promising for wound healing because of their antibacterial efficacy, biocompatibility, and biodegradability, though their healing mechanisms remain unclear. This study explores the cellular and molecular mechanisms of wound healing with chitosan nanofibrous dressings.

Methods

Thirty-nine Sprague Dawley rats were divided into three groups based on the type of dressings administered: (1) chitosan nanofibrous dressing + transparent film, (2) commercial scaffold + transparent film, and (3) transparent film alone (control). Full-thickness wounds (2 cm × 2 cm) were created on the dorsum, splinted, and covered with dressings. Evaluations at 7, 14, and 21 days included histological analysis, …

The Illusion Of Internal Models In Biological Movement, Madhur Mangalam

Journal Articles

The concept of internal models dominates contemporary theories of sensorimotor control, with researchers across neurosciences, specifically motor control, routinely explaining observed behaviors through computational representations that supposedly exist within the nervous system. In this perspective, I present a critical examination of internal model frameworks in sensorimotor control. I argue that representational approaches mischaracterize biological systems for several fundamental reasons: (1) Internal models require homuncular interpreters, creating infinite regress problems; (2) The purported neural implementations of internal models remain empirically elusive despite decades of research; (3) Biological movement systems exhibit multiscale, nonlinear, and non-Gaussian dynamics that fundamentally defy reduction to conventional …

The Myth Of The Bayesian Brain, Madhur Mangalam

Journal Articles

The Bayesian brain hypothesis—the idea that neural systems implement or approximate Bayesian inference—has become a dominant framework in cognitive neuroscience over the past two decades. While mathematically elegant and conceptually unifying, this paper argues that the hypothesis occupies an ambiguous territory between useful metaphor and testable, biologically plausible mechanistic explanation. We critically examine the key claims of the Bayesian brain hypothesis, highlighting issues of unfalsifiability, biological implausibility, and inconsistent empirical support. The framework’s remarkable flexibility in accommodating diverse findings raises concerns about its explanatory power, as models can often be adjusted post hoc to fit virtually any data pattern. We …

An Aquatic Treadmill Alters Lower Limb Walking Dynamics In Typically Developing Children And Children With Cerebral Palsy, Oluwaseye P. Odanye, Joseph Harrington, Aaron Likens, David Kingston, Brian Knarr

Journal Articles

This block-randomized crossover study investigated how a speed-modulated aquatic treadmill (AT) impacts the walking biomechanics of pediatric gait. Eight cerebral palsy (CP) and fifteen typically developing (TD) children walked at normal, slow, and fast treadmill speeds in AT and dry treadmill (DT) conditions. The joint angles of participants were calculated from inertial measurement units to derive sample entropy (SE) measures that quantified the regularity or complexity of motion. A hierarchical statistical model revealed that the CP group had lower SE values for the hip, knee, and ankle joints in the AT and at slower than faster treadmill speeds. Only the …

University Of Nebraska At Omaha Division Of Biomechanics And Research Development Annual Report 2022-2023, Uno Biomechanics

Biomechanics Annual Report

This report contains:

A letter from the Director: Dr. Nick Stergiou

Highlights articles

Our ne Cobre: the Center for Cardiovascular Research in Biomechanics (CRiB) articles

The Center for Research in Human Movement Variability (MOVCENTR) articles

People of UNO Biomechanics

Student Centered articles

Faculty Success articles

Education Initiative articles

Enhancing Walking Performance In Patients With Peripheral Arterial Disease: An Intervention With Ankle-Foot Orthosis, Farahnaz Fallahtafti, Kaeli K. Samson, Zahra Salamifar, Jason M. Johanning, Iraklis Pipinos, Sara A. Myers

Journal Articles

Lower extremity peripheral artery disease (PAD) is a cardiovascular condition manifesting from narrowed or blocked arteries supplying the legs. Gait is impaired in patients with PAD. Recent evidence suggests that walking with carbon fiber ankle foot orthoses (AFOs) can improve patient mobility and delay claudication time. This study aimed to employ advanced biomechanical gait analysis to evaluate the impact of AFO intervention on gait performance among patients with PAD. Patients with claudication had hip, knee, and ankle joint kinetics and kinematics assessed using a cross-over intervention design. Participants walked over the force platforms with and without AFOs while kinematic data …

Lower Body Gait Variability As A Distinguishing Feature In Humans, Tyler M. Wiles, Seung Kyeom Kim, Nick Stergiou, Aaron D. Likens

UNO Student Research and Creative Activity Fair

Most humans have a fingerprint that is unique and persists throughout life. The same may be true for gait. Each person is unique physiologically and biomechanically, and has experienced a unique progression of life including injuries, habits, hobbies, or lifestyles that all contribute to navigating the world. Those individualized experiences, whether intended or not, are potentially on display in gait. We hypothesized that there are gait characteristics intrinsic and unique to everyone, so that everyone has a unique “gaitprint”, similar to humans possessing unique fingerprints. To test our hypothesis, we recruited thirty healthy young adults between the ages 19-35 as …

Postural Perturbations Change The Adaptive Response To Control, Brian Schlattmann

UNO Student Research and Creative Activity Fair

Dexterity involves cohesive and functional coordination that extends throughout the body. Successful task completion while standing hinges on synchronizing various anatomical components, ensuring postural stability across the 2D support surface. Canonical approaches account for postural sway only along the anatomical anteroposterior (AP) and mediolateral (ML) axes....

Functional Outcomes Of Noninvasive Sensory Feedback In Upper Limb Prostheses: A Meta-Analysis, Libby Caldwell

UNO Student Research and Creative Activity Fair

Noninvasive sensory feedback applies vibration or pressure to the residual limb and is thought to improve the functionality of upper limb prostheses. However, the efficacy of this approach has not been sufficiently investigated, particularly regarding actual amputee efficacy. The purpose of this study was to evaluate the functional benefits of noninvasive sensory feedback in upper limb prostheses through a meta-analysis. Electronic databases (MEDLINE, Web of Science, and PubMed) were searched up to October 2022 using the following search terms: (prosthesis OR prosthetic) AND (hand OR arm OR forearm OR transradial OR “upper limb” OR “upper extremity) AND (tactile OR haptic …

Walking With A Load On Wheels: Potential Effects Of Bidirectional Springs On Walking Economy, Hiva Razavi, Philippe Malcolm

UNO Student Research and Creative Activity Fair

Walking with a Load on Wheels: Potential Effects of Bidirectional Springs on Walking Economy

Have you ever noticed how your arms alternatively flex and extend when pushing a heavy shopping cart? Accelerating and decelerating heavy masses, such as a shopping cart, can require much effort. During walking, we alternatively accelerate and decelerate our Center of Mass (COM) in every gait cycle, which can require even more effort if we accelerate and decelerate a load while walking. Theoretically, this effort can be reduced by timing the acceleration and deceleration of the load's mass opposite to the individual's COM. Previous studies have …

Negative Impact Of Aging On Gait Autocorrelation: A Mixed-Effects Analysis Of Stride Interval Dynamics, Theodore Deligiannis, Tyler M. Wiles, Seung Kyeom Kim, Nikolaos Stergiou, Aaron Likens

UNO Student Research and Creative Activity Fair

NEGATIVE IMPACT OF AGING ON GAIT AUTOCORRELATION: A MIXED-EFFECTS ANALYSIS OF STRIDE INTERVAL DYNAMICS

Theodore A. Deligiannis^1*, Tyler M. Wiles¹, Seung Kyeom Kim¹, Nick Stergiou^1,2, Aaron D. Likens¹

¹Department of Biomechanics, University of Nebraska at Omaha

*Corresponding author’s email: [email protected]

Presentation preference: Podium

Traditional gait metrics, like speed, cadence, coordination, as well as non-linear measures, appear related to Timed Up and Go (TUG). Timed Up and Go is a clinical measurement related to physical, socioeconomic, and psychological parameters, as well as overall health. TUG can be used as a health …

Inter-Joint Variability And Age-Related Changes In Human Walking, Mehrnoush Haghighatnejad, Tyler Wiles, Seung Kyeom Kim, Aaron Likens, Nicholas Stergiou

UNO Student Research and Creative Activity Fair

Inter-Joint Variability and Age-Related Changes in Human Walking

Mehrnoush Haghighatnejad¹*, Tyler M. Wiles¹, Seung Kyeom Kim¹, Nick Stergiou^1,2, Aaron D. Likens¹

¹Department of Biomechanics, University of Nebraska at Omaha

²Department of Physical Education and Sport Science, Aristotle University, Thessaloniki, Greece

*Corresponding author’s email: [email protected]

Presentation Preference: Poster

Humans routinely perform a variety of activities such as walking, running, driving, and typing, all of which require coordination among different body joints. For instance, walking and running involve rhythmic movements of the arms and legs. The involvement of the upper …

Lower Limb Revascularization Leads To Faster Walking But With Less Efficient Mechanics In Claudicating Patients, Alex Dzewaltowski, Iraklis Pipinos, Molly Schieber, Jason Johanning, George P. Casale, Sara A. Myers, Philippe Malcolm

Journal Articles

Peripheral artery disease (PAD) is characterized by reduced blood flow to the extremities due to atherosclerosis. Studies report impaired gait mechanics in patients with lower extremity PAD. We hypothesized that revascularization surgery would improve gait mechanics when quantified by net lower limb joint work across the stance phase of walking. We performed gait analyses in 35 patients with PAD and 35 healthy, older adults. Patients with PAD performed a walking protocol prior to and six months following revascularization surgery. Healthy adults only took part in a single walking session. Lower limb joint powers were calculated using inverse dynamics and …

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: …

Quantifying Non-Gaussian Intermittent Fluctuations In Physiology: Multiscale Probability Density Function Analysis Using The Savitzky-Golay Detrending, Madhur Mangalam, Damian G. Kelty-Stephen, Eiichi Watanabe, Ken Kiyono

Journal Articles

When measuring physiological data, the central limit theorem typically implies a consistent variance, resulting in data that closely follow a Gaussian distribution. However, physiological measurements often deviate from this expectation, increasing variance due to nonlinear correlations across various scales. The challenge lies in testing these tails, which comprise only rare and extreme values. We introduce multiscale probability density function (PDF) analysis, a method that estimates this non-Gaussianity parameter for physiological fluctuations in each of multiple timescales. We gain valuable insights into the observed distributions with heavier tails and nonlinear correlations by exploring the relationship between non-Gaussianity and logarithmic scale. To …

Multifractality In Stride-To-Stride Variations Reveals That Walking Involves More Movement Tuning And Adjusting Than Running, Taylor J. Wilson, Madhur Mangalam, Nicholas Stergiou, Aaron Likens

Journal Articles

Introduction: The seemingly periodic human gait exhibits stride-to-stride variations as it adapts to the changing task constraints. The optimal movement variability hypothesis (OMVH) states that healthy stride-to-stride variations exhibit “fractality”—a specific temporal structure in consecutive strides that are ordered, stable but also variable, and adaptable. Previous research has primarily focused on a single fractality measure, “monofractality.” However, this measure can vary across time; strideto-stride variations can show “multifractality.” Greater multifractality in stride-tostride variations would highlight the ability to tune and adjust movements more.

Methods: We investigated monofractality and multifractality in a cohort of eight healthy adults during self-paced walking and …

Temporal Organization Of Stride-To-Stride Variations Contradicts Predictive Models For Sensorimotor Control Of Footfalls During Walking, Madhur Mangalam, Damian G. Kelty-Stephen, Joel H. Sommerfeld, Nicholas Stergiou, Aaron Likens

Journal Articles

Walking exhibits stride-to-stride variations. Given ongoing perturbations, these variations critically support continuous adaptations between the goal-directed organism and its surroundings. Here, we report that stride-to-stride variations during self-paced overground walking show cascade-like intermittency—stride intervals become uneven because stride intervals of different sizes interact and do not simply balance each other. Moreover, even when synchronizing footfalls with visual cues with variable timing of presentation, asynchrony in the timings of the cue and footfall shows cascade-like intermittency. This evidence conflicts with theories about the sensorimotor control of walking, according to which internal predictive models correct asynchrony in the timings of the cue …

Coordination Rigidity In The Gait, Posture, And Speech Of Persons With Parkinson’S Disease, Dobromir Dotov, Valérie Cochen De Cock, Valérie Driss, Benoît Brady, Simone Dalla Bella

Journal Articles

Parkinson’s disease (PD) is associated with reduced coordination abilities. These can result either in random or rigid patterns of movement. The latter, described here as coordination rigidity (CR), have been studied less often. We explored whether CR was present in gait, quiet stance, and speech—tasks involving coordination among multiple joints and muscles. Kinematic and voice recordings were used to compute measures describing the dynamics of systems with multiple degrees of freedom and nonlinear interactions. After clinical evaluation, patients with moderate stage PD were compared against matched healthy participants. In the PD group, gait dynamics was associated with decreased dynamic divergence—lower …

Ergodic Characterization Of Nonergodic Anomalous Diffusion Processes, Madhur Mangalam, Ralf Metzler, Damian G. Kelty-Stephen

Journal Articles

Anomalous diffusion in various complex systems abounds in nature and spans multiple space and time scales. Canonical characterization techniques that rely upon mean squared displacement break down for nonergodic processes, making it challenging to characterize anomalous diffusion from an individual time-series measurement. Nonergodicity reigns when the time-averaged mean square displacement differs from the ensemble-averaged mean squared displacement even in the limit of long measurement series. In these cases, the typical theoretical results for ensemble averages cannot be used to understand and interpret data acquired from time averages. The difficulty then lies in obtaining statistical descriptors of the measured diffusion process …

Betaglycan Promoter Activity Is Differentially Regulated During Myogenesis In Zebrafish Embryo Somites, Lizbeth Ramírez-Vidal, Tonatiuh Molina-Villa, Valentín Mendoza, Carlos Alberto Peralta-Álvarez, Augusto Cesar Poot-Hernández, Dobromir Dotov, Fernado López-Casillas

Journal Articles

Background

Betaglycan, also known as the TGFβ type III receptor (Tgfbr3), is a co-receptor that modulates TGFβ family signaling. Tgfbr3 is upregulated during C2C12 myoblast differentiation and expressed in mouse embryos myocytes.

Results

To investigate tgfbr3 transcriptional regulation during zebrafish embryonic myogenesis, we cloned a 3.2 kb promoter fragment that drives reporter transcription during C2C12 myoblasts differentiation and in the Tg(tgfbr3:mCherry) transgenic zebrafish. We detect tgfbr3 protein and mCherry expression in the adaxial cells concomitantly with the onset of their radial migration to become slow-twitch muscle fibers in the Tg(tgfbr3:mCherry). Remarkably, this expression displays …

Gaze During Turning In Older Adults, Kalina Mavrov

Theses/Capstones/Creative Projects

To navigate complex environments, our gaze needs to attenuate to locomotor tasks, such as walking and turning. Shifting gaze (i.e., rotation of the eyes and head), is important when moving through different environments. The aim of this study was to compare gaze anticipation during clinical tests and complex real-world locomotion. I hypothesized that older adults would shift their gaze in a new heading direction in anticipation of turns. I further predicted increased gaze anticipation in tasks that have a high demand for spatial orientation. Participants were asked to complete clinical tasks consisting of a 2-minute walk, figure-8, and 360-turning in …

Accelerometry-Based Analysis Of Postural Sway In Parkinson's Disease Patients With Levodopa-Induced Dyskinesia, Chandler Brock

UNO Student Research and Creative Activity Fair

Parkinson’s disease (PD) is a progressive neurodegenerative disorder, with patient numbers projected to double to 12 million in the next 20 years. Levodopa-induced dyskinesia (LID) is a major problem associated with the long-term use of levodopa for symptomatic treatment of PD. These involuntary movements can become disabling and may interfere with quality of life. Our prior research showed that PD w/ LID were less stable while standing (i.e., increased postural sway) and had a higher incidence of falls. The aim of this study is to determine if postural sway properties are altered by LID via decomposing the sway signal. We …

Walking Easier By Attaching A Spring-Mass To The Body: A Preliminary Simulation, Hiva Razavi, Philippe Malcolm

UNO Student Research and Creative Activity Fair

When carrying or pushing a load, more force is needed to accelerate and decelerate the additional mass, increasing Ground Reaction Force (GRF). However, this can be reduced by synchronizing the object's movement with the individual's Center of Mass (COM) using antiphase acceleration and deceleration. Past studies have shown this can decrease muscle work and metabolic costs. This study aimed to determine optimal spring parameters to minimize horizontal GRF (GRFh) when pushing a cart by connecting the human to the cart with a spring and damper system.

Three walking conditions were simulated in MATLAB: 1) Normal walking; 2) Walking with a …

Attenuated Skeletal Muscle Metabolism Explains Blunted Reactive Hyperemia After Prolonged Sitting, Cody Anderson, Elizabeth Pekas, Michael Allen, Song-Young Park

UNO Student Research and Creative Activity Fair

Introduction: Although reduced post-occlusive reactive hyperemia (PORH) after prolonged sitting (PS) has been reported as impaired microvascular function, no specific mechanism(s) have been elucidated. One potential mechanism, independent of microvascular function, is that an altered muscle metabolic rate (MMR) may change the magnitude of PORH by modifying the oxygen deficit achieved during cuff-induced arterial occlusions. We speculated that if MMR changes during PS, this may invalidate current inferences about microvascular function during PS. Objective: Therefore, the objective of this study was to examine if peripheral leg MMR changes during PS and to ascertain whether the change in the oxygen deficit …

The Effect Of Exoskeleton Footwear On Joint Angular Motion During Walking In Patients With Peripheral Artery Disease, Zahra Salamifar, Farahnaz Fallahtafti, Iraklis I. Pipinos, Jason M. Johanning, Sara Myers

UNO Student Research and Creative Activity Fair

Gait, Lower Extremity, Peripheral Artery Disease, Joint Angle, Exoskeleton Footwear, Exoskeleton, Assistive Device, Walking.

The Effects Of Demographics And Risk Factors On The Morphological Characteristics Of Human Femoropopliteal Arteries, Sayed Ahmadreza Razian, Majid Jadidi, Alexey Kamenskiy

UNO Student Research and Creative Activity Fair

Background: Disease of the lower extremity arteries (Peripheral Arterial Disease, PAD) is associated with high morbidity and mortality. During disease development, the arteries adapt by changing their diameter, wall thickness, and residual deformations, but the effects of demographics and risk factors on this process are not clear.

Methods: Superficial femoral arteries from 736 subjects (505 male, 231 female, 12 to 99 years old, average age 51±17.8 years) and the associated demographic and risk factor variables were used to construct machine learning (ML) regression models that predicted morphological characteristics (diameter, wall thickness, and longitudinal opening angle resulting from the …

Long-Term Use Of An Ankle-Foot Orthosis Intervention In Patients With Peripheral Artery Disease Using The Integrated Promoting Action On Research Implementation In Health Services (I-Parihs) Framework, Ayisha Bashir, Danae Dinkel, Iraklis Pipinos, Paul Estabrooks, Jason Johanning, Sara A. Myers

Journal Articles

Background

Peripheral artery disease (PAD) is a cardiovascular disease that limits patients' walking ability. Persistent ankle-foot orthosis (AFO) use may increase the distance patients can walk as well as physical activity.

Purpose

The purpose of the study was to determine the implementation and patients' perspectives related to the use or disuse of the AFO intervention six months post-intervention. This study was guided by a semi-structured interview and survey based on the integrated Promoting Action on Research Implementation in Health Services (i-PARIHS) constructs.

Design

A convergent mixed methods design was used to evaluate participants' perceptions six months following a three-month AFO …