Biomechanics Commons^™

Use Of Motor Abundance In Young And Older Adults During Dual-Task Treadmill Walking, Leslie M. Decker, Fabien Cignetti, Jane F. Potter, Stephanie A. Studenski, Nikolaos Stergiou

Journal Articles

Motor abundance allows individuals to perform any task reliably while being variable in movement's particulars. The study investigated age-related differences in this feature when young adults (YA) and older adults (OA) performed challenging tasks, namely treadmill walking alone and while performing a cognitive task. A goal function for treadmill walking was first defined, i.e., maintain constant speed at each step, which led to a goal equivalent manifold (GEM) containing all combinations of step time and step length that equally satisfied the function. Given the GEM, amounts of goal-equivalent and non-goal-equivalent variability were afterwards determined and used to define an index …

Persons With Multiple Sclerosis Show Altered Joint Kinetics During Walking After Participating In Elliptical Exercise, Jessie M. Huisinga, Kendra K. Schmid, Mary Filipi, Nikolaos Stergiou

Journal Articles

Patients with multiple sclerosis (MS) experience abnormal gait patterns and reduced physical activity. The purpose of this study was to determine if an elliptical exercise intervention for patients with MS would change joint kinetics during gait toward healthy control values. Gait analysis was performed on patients with MS (n = 24) before and after completion of 15 sessions of supervised exercise. Joint torques and powers were calculated, while also using walking velocity as a covariate, to determine the effects of elliptical exercise on lower extremity joint kinetics during gait. Results show that elliptical exercise significantly altered joint torques at the …

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 ( …

Relative Roughness: An Index For Testing The Suitability Of The Monofractal Model, Vivien Marmelat, Kjerstin Torre, Didier Delignières

Journal Articles

Fractal analyses have become very popular and have been applied on a wide variety of empirical time series. The application of these methods supposes that the monofractal framework can offer a suitable model for the analyzed series. However, this model takes into account a quite specific kind of fluctuations, and we consider that fractal analyses have been often applied to series that were completely outside of its relevance. The problem is that fractal methods can be applied to all types of series, and they always give a result, that one can then erroneously interpret in the context of the monofractal …

Comparing Thigh Muscle Cross-Sectional Area And Squat Strength Among National Class Olympic Weightlifters, Power Lifters, And Bodybuilders, James J. Di Naso, Brian L. Pritschet, John D. Emmett, Jill W. Owen, Jeffrey Willardson, Travis W. Beck, Jason M. Defreitas, Fabio E. Fontana

Faculty Research and Creative Activity

Few studies have compared anthropometric characteristics among national class athletes from different resistance training disciplines, such as Olympic Weightlifting (OL), Power Lifting (PL), and Bodybuilding (BB). Objective: The purpose of the current study was to determine if significant differences exist in the relationship between thigh muscle cross-sectional area and back squat strength among national class athletes from the sports of OL, PL, and BB. Methods: Fifteen national class athletes were assessed for back squat strength, mid-thigh circumference, and mid-thigh skinfold from which total thigh cross-sectional was estimated. A series of One-Way ANOVAs and Pearson Product Moment Correlations were used to …

Biomechanical Testing On Cadaveric Spines For Different Treatments That Affect Lumbar Stability, Sabrina Alejandra Gonzalez Blohm

USF Tampa Graduate Theses and Dissertations

Stenosis is one of the most common causes for spinal surgery. Laminectomy decompression and fusion are surgical procedures prescribed for this condition. The intention of this work was to investigate the effects of a laminectomy decompression, followed by fusion, on a lumbar functional spinal unit (FSU) through in vitro dynamic (±8Nm at 0.125Hz) and quasi-static (±7.5Nm at 0.1Hz) biomechanical tests, for flexion, extension, bending and rotation motions.

Six FSUs where disarticulated from four human cadaveric lumbar spines (63 ± 12 years) and were tested under the following sequence: (1) intact, (2) laminectomy decompression, and (3) Pedicle Screw System (PSS), using …

Digital And Clinical Refractometers Are Valid Instruments For The Measure Of Hydration Status, A. J. Niemann, S. W. Yeargin, L. E. Eberman, H. M. Mata, H. A. Adams, D. J. Dziedzicki

Symposium 2012

Although some instruments have been validated for clinical measure of hydration status, new and currently invalid instruments are available for purchase and clinical use. Athletic trainers commonly use these instruments to assess hydration status for weight checks and body mass loss charts due to their ease of use. However, the validity of these popular instruments has not yet been established.

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 …

Sensitivity Of The Wolf’S And Rostein’S Algorithms To Evaluate Local Dynamic Stability From Small Gait Data Sets, Fabien Cignetti, Leslie M. Decker, Nikolaos Stergiou

Journal Articles

The Wolf’s (W-algorithm) and Rosenstein’s (R-algorithm) algorithms have been used to quantify local dynamic stability (largest Lyapunov exponent, λ ₁) in gait, with prevalence of the latter one that is considered more suitable for small data sets. However, such a claim has never been investigated. To address it, the λ ₁ of the Lorenz attractor was estimated using small data sets and varied delays and embedding dimensions. Overall, the λ ₁ estimates from the R-algorithm got closer to the theoretical exponent than those from the W-algorithm. The W-algorithm also overestimated λ _{1 …}

A Biomechanical Analysis Of The Gymnastics Cartwheel Using Dartfish Motion Analysis Software, Keilea Bullard

Undergraduate Research Conference

The biomechanical analysis required videotaping two subjects performing the cartwheel to the best of their ability. Strict protocols were followed to ensure the analysis was accurate. In order to measure distances in the Dartfish program, an object of known length had to be recorded. Subjects were asked to hold a scaling rod for ten seconds before beginning their trials. Subjects recorded four trials each and all data was imported into the Dartfish program. Average trials for both subjects were chosen to be analyzed extensively for strengths, weaknesses and most importantly the overall biomechanics of the cartwheel. The subjects’ video was …

Gait Variability Measures Reveal Differences Between Multiple Sclerosis Patients And Healthy Controls, Jeffrey P. Kaipust, Jessie M. Huisinga, Mary Filipi, Nikolaos Stergiou

Journal Articles

The purpose of this study was to determine the differences in gait variability between patients with multiple sclerosis (MS) and healthy controls during walking at a self-selected pace. Methods: Kinematics were collected during three minutes of treadmill walking for 10 patients with MS and 10 healthy controls. The Coefficient of Variation (CoV), the Approximate Entropy (ApEn) and the Detrended Fluctuation Analysis (DFA) were used to investigate the fluctuations present in stride length and step width from continuous strides. Results: ApEn revealed that patients with MS had significantly lower values than healthy controls for stride length (p < .001) and step width (p < .001). Conclusions: ApEn results revealed that the natural fluctuations present during gait in the stride length and step width time series are more regular and repeatable in patients with MS. These changes implied that patients with MS may exhibit reduced capacity to adapt and respond to perturbations during gait.

Evaluation Of Transfer Technologies To Preserve Shoulder Function In Sci, Karen Michelle Mann

USF Tampa Graduate Theses and Dissertations

This study investigated a series of independent unassisted and device-assisted transfers from a wheelchair to vehicle mock-up and vice versa while simultaneously capturing kinematic, kinetic and electromyographic (EMG) data of impaired volunteers. The study provides a venue for observation and evaluation of upper extremity (UE) joint stresses, muscular force and functional demands associated with transfers in persons with spinal cord injury (SCI) to ultimately prevent UE injury, minimize excessive stress, preserve functionality and limit pain. If people with SCI lose function of their UEs, due to pain and/or degeneration, they must then rely on others for everyday tasks.

Five paraplegic …

Frontal Joint Dynamics When Initiating Stair Ascent From A Walk Versus A Stand, Srikant Vallabhajosula, Jenna M. Yentes, Nikolaos Stergiou

Journal Articles

Ascending stairs is a challenging activity of daily living for many populations. Frontal plane joint dynamics are critical to understand the mechanisms involved in stair ascension as they contribute to both propulsion and medio-lateral stability. However, previous research is limited to understanding these dynamics while initiating stair ascent from a stand. We investigated if initiating stair ascent from a walk with a comfortable self-selected speed could affect the frontal plane lower-extremity joint moments and powers as compared to initiating stair ascent from a stand and if this difference would exist at consecutive ipsilateral steps on the stairs. Kinematics data using …

Do Lower-Extremity Joint Dynamics Change When Stair Negotiation Is Initiated With A Self-Selected Comfortable Gait Speed?, Srikant Vallabhajosula, Jenna M. Yentes, Mira Momcilovic, Daniel Blanke, Nikolaos Stergiou

Journal Articles

Previous research on the biomechanics of stair negotiation has ignored the effect of the approaching speed. We examined if initiating stair ascent with a comfortable self-selected speed can affect the lower-extremity joint moments and powers as compared to initiating stair ascent directly in front of the stairs. Healthy young adults ascended a custom-built staircase instrumented with force platforms. Kinematics and kinetics data were collected simultaneously for two conditions: starting from farther away and starting in front of the stairs and analyzed at the first and second ipsilateral steps. Results showed that for the first step, participants produced greater peak knee …

Wearing A Safety Harness During Treadmill Walking Influences Lower Extremity Kinematics Mainly Through Changes In Ankle Regularity And Local Stability, Leslie M. Decker, Fabien Cignetti, Nikolaos Stergiou

Journal Articles

Background: Wearing a harness during treadmill walking ensures the subject’s safety and is common practice in biomedical engineering research. However, the extent to which such practice influences gait is unknown. This study investigated harness-related changes in gait patterns, as evaluated from lower extremity kinematics during treadmill walking.

Findings: Healthy subjects (n = 10) walked on a treadmill at their preferred speed for 3 minutes with and without wearing a harness (LiteGait®, Mobility Research, Inc.). In the former condition, no weight support was provided to the subjects. Lower extremity kinematics was assessed in the sagittal plane from the mean (meanRoM), standard …

Feather Biomechanics Of Penguins And Other Seabirds, Katherine Elizabeth Johnson

Theses Digitization Project

Although many aspects of penguin biology have been studied, the feathers have received less attention except with regard to thermoregulation. The biomechanics of penguin feathers are the focus of this thesis. By studying penguins in comparison to other wing-propelled aquatic fliers, it may be possible to understand how penguin feathers evolved. Fourteen species were sampled, including aerial flyers, aerial flyers that are also wing propelled divers, as well as flightless wing propelled divers.

An Eccentric Intervention Of The Flexor-Pronator Mass To Impact Overhead Throwing Distance And Velocity, Ricker Stanton Adkins

Online Theses and Dissertations

This study focused on the pronator-flexor mass of the elbow and its role in the overhead throwing motion. This specific muscle group is responsible for primary pronation and flexion at the elbow joint, while also reducing valgus stress from compromising the ulnar collateral ligament.

Twenty-three participants were put through a short throwing progression that was focused on their velocity and overall distance thrown from a standing position. After baseline testing was completed participants underwent a short intervention to determine if the intervention would impact all dependent variables. Experimental and non-experimental groups were compared using a repeated measures ANOVA which found …

Nebraska Biomechanics Core Facilty 2011-2012 Annual Report, Issue 10, Nebraska Biomechanics Core Facility

Biomechanics Annual Report

June 2011 - August 2012

This issue features Featured news, Staff updates, Grants and Projects, Collaborations, Visitors, Awards, Publications, Travels, and Support.

Biophysical And Biochemical Factors In The Cellular Microenvironment; Effects On Cell Migration And Invasion, Shalini Menon

Wayne State University Dissertations

Cellular migration is a vital process central to many physiological events including development, immune surveillance and wound healing. However, migration and invasion are not unique to normal physiology, they are also key determinants in the progression of disease states such as cancer. Given the significance of migration it is important that we understand how the process is regulated intracellularly and the various stimuli that can promote it. Even though the role of biochemical factors in mediating migration has been studied extensively, the role of biophysical factors in modulating migration and invasion is less appreciation. The biochemical and biophysical components of …

Impacts On Balance When Walking In Occupational Footwear, Harish Chander

Electronic Theses and Dissertations

Hazards and challenges present in the workplace pose a number of potential risks for injuries and illness. Nearly 3.1 million nonfatal workplace injuries and illness were reported in 2010 (BLS, 2010). The probability of falls has been related to balance decrements. Further, an important point of distinction is 45% of all falls have been attributed to inappropriate footwear (Menant et al. 2008) Previous studies have shown decrements in balance as a result of different footwear (Menant et al. 2008) and after an increased workload over a specific period of time (Yaggie & McGregor, 2002; Gribble & Hertel, 2004). Occupational footwear …

Football Helmet Fitment And Its Effect On Helmet Performance, Ron Jadischke

Wayne State University Theses

A method and system to objectively quantify helmet fitment was designed and developed. It measures the pressure between the energy-absorbing material in the helmet and the athlete's head. This system is also capable of measuring surface pressure during impact events. A volunteer-based field study was conducted to quantify how helmets were fitting athletes in a real-life setting. The helmets fit athletes in varying degrees of tightness and evenness. Most athletes (59%) had the highest pressures in the frontal area and 29% had the highest pressure in the occipital area. A large-sized helmet on the Hybrid III headform represented how most …

Contact Pressure Distribution Of Osteochondral Defects Of The Knee: Effects Of Non-Vertical Walls, Scott Ensminger

Wayne State University Theses

Purpose: To examine the relationship between well-shouldered osteochondral defects and

defects of different geometries by studying their effects on rim stress concentration and

load redistribution in the human knee.

Methods: Ten fresh-frozen cadaveric knees were mounted at 30° of flexion in a materials

testing machine. Digital electronic pressure sensors were placed in the medial and lateral

compartments of the knee. Dynamic pressure readings were recorded throughout the

loading and holding phases as each knee was loaded to 700N and held for 5 seconds.

Artificial defects were created in each knee to simulate well-shouldered defects and

beveled-defects. Loading was repeated for …

Reliability Of Semiautomated Computational Methods For Estimating Tibiofemoral Contact Stress In The Multicenter Osteoarthritis Study, Donald D. Anderson, Neil A. Segal, Andrew M. Kern, Michael C. Nevitt, James C. Torner, John A. Lynch

Journal Articles

Recent findings suggest that contact stress is a potent predictor of subsequent symptomatic osteoarthritis development in the knee. However, much larger numbers of knees (likely on the order of hundreds, if not thousands) need to be reliably analyzed to achieve the statistical power necessary to clarify this relationship. This study assessed the reliability of new semiautomated computational methods for estimating contact stress in knees from large population-based cohorts. Ten knees of subjects from the Multicenter Osteoarthritis Study were included. Bone surfaces were manually segmented from sequential 1.0 Tesla magnetic resonance imaging slices by three individuals on two nonconsecutive days. Four …

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 …

Estimates Of Critical Power And Anaerobic Work Capacity From A Single, All-Out Test Of Less Than 3-Min, H C. Bergstrom, T J. Housh, Jorge M. Zuniga, C L. Camic, D A. Traylor, R W. Lewis, R J. Schmidt, G O. Johnson

Journal Articles

The purpose of this study was to determine if Critical Power (CP) and Anaerobic Work Capacity (AWC) could be estimated from a single, all-out test of less than 3-min. Twenty-eight subjects (mean ± SD: age 23.3 ± 3.3 years, body mass 71.6 ± 16 kg) performed an incremental cycle ergometer test to exhaustion to determine peak oxygen consumption rate and heart rate peak. The 3-min all-out test was used to determine the criterion and six estimated values of CP and AWC. The criterion critical power (CP180) and anaerobic work capacity (AWC180) values were determined from the 3-min all-out test and …

Training Dual-Task Walking In Community-Dwelling Adults Within 1 Year Of Stroke: A Protocol For A Single-Blind Randomized Controlled Trial, Prudence Plummer-D'Amato, Anastasia Kyvelidou, Dagmar Sternad, Bijan Najafi, Raymond M. Villalobos, David Zurakowski

Journal Articles

No abstract provided.

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 …

The Biomechanics Of Tongue Projection In The Frog _Rana Pipiens_: Dynamics And Temperature Effects, Paula Sandusky

USF Tampa Graduate Theses and Dissertations

Ectotherms such as frogs must either function within environments with temperatures amenable to their physiological needs, or find means to reduce the impact of temperature on their activities. Recent studies on reptile and amphibian feeding have shown convergent use of elastic recoil to drive feeding movements, thereby decoupling temperature's effects on muscle from movement and allowing the animals to feed over broader temperature ranges. Rana pipiens specimens (n=5) were exposed to three ambient temperatures (10°, 15°, and 25° C) at which feeding behavior was imaged at 6000 Hz. The image sequences yielded detailed kinematic and dynamic information for jaw, tongue, …

Endurance Markers Are Related With Local Neuromuscular Response For The Intact But Not For The Acl Reconstructed Leg During High Intensity Running, Kostas Patras, Giorgos Ziogas, Stavros Ristanis, Elias Tsepis, Vasilis Tsiaras, Nikolaos Stergiou, Anastasios D. Georgoulis

Journal Articles

AIM: It has been demonstrated that the local neuromuscular response during high intensity exercise has a strong relationship with endurance markers. However, a diminished neuromuscular response has been reported for the operated leg in athletes having undergone anterior cruciate ligament reconstruction (ACLR). The purpose of the present study was to examine the relationships between endurance markers and the EMG response during high intensity running in ACLR athletes. METHODS: Fourteen ACLR soccer players underwent a GXT test to volitional exhaustion and a 10-min bout of high intensity running. During the 10-min bout, EMG data were recorded at the 3rd …