Biomechanics Commons^™

Comparison Of Clinician Assisted Versus Unassisted Pnf Stretching On Hamstring Flexibility, Isometric Force Output, And Maximum Vertical Jump Height, Joel T. Lockhart

Theses and Dissertations

Introduction: Hamstring strains are among one of the most common acute injuries that occur in soccer players. Previous research has shown that reduced hamstring flexibility is a risk factor for injury, however this is modifiable through stretching. Some stretching techniques have contributed to decreased performance on measures important to success in sport. Proprioceptive neuromuscular facilitation (PNF) is one effective stretching technique to improve hamstring flexibility, but requires a trained partner or clinician to perform properly. It is unknown if the performance of PNF stretching without a clinician’s assistance could be as effective. It is also unknown if PNF stretching affects …

The Effects Of Trx Suspension Training On An Asymmetrical Weight Shift During A Double-Leg Squat, Samantha J. Shruck

Theses and Dissertations

Context: It is estimated that 54% of all sport related injuries are to the lower extremity, specifically the knee and ankle. Following injury, many individuals demonstrate an asymmetrical weight shift during a double-leg squat, which may increase risk of further injury. Asymmetries are driven by a variety of factors including range of motion and neuromuscular control. The goal of rehabilitation is to identify asymmetrical movement and utilize evidence-based techniques to retrain deficient movement patterns. The double-leg squat is a reliable movement task to identify asymmetrical weight shifts. Based on the theory and purpose of suspension training (TRX), it may be …

P18. Backstroke Start Performance: The Impact Of Using The Omega Backstroke Ledge, Gordon E. Barkwell, James P. Dickey

Western Research Forum

Background: FINA recently approved use of the “backstroke ledge” (Omega OBL2) to improve backstroke start performance in competition, but its performance has not been thoroughly evaluated. The purpose of this study was to compare starts performed on a flat wall to those performed with the OBL2, and to identify factors that contribute to better start performance. Methods: Ten elite backstroke swimmers performed three flat-wall and three OBL2 starts. Horizontal impulse, vertical impulse, takeoff velocity and takeoff angle were calculated from the force plate data. Entry distance, time to 10 m and start of hip and knee extension were recorded using …

P17. P3b Event-Related Potentials Show Changes In Varsity Football Players Due To Accumulated Sub-Concussive Head Impacts, Jeffrey S. Brooks, James W. Thompson, James P. Dickey

Western Research Forum

BACKGROUND: Concussion has been a focus in football at all levels of participation. However, there is a growing appreciation that repetitive sub-concussive impacts may have more significant effects on overall neurological health than the isolated diagnosed concussions that have been the focus of recent research. The purpose of this study was to evaluate the relationship between the number of head impacts that players experience throughout the season and their P300 evoked potential.

METHODS: Canadian university football players (n=45) were separated into three groups based on player mass and position/skill (small-skilled, big-skilled and big-unskilled). Groups were separated into low and high …

P27. Acute Impact Of An Extremely Low Frequency Magnetic Stimulus On Human Neurophysiological Function - Magnetophosphene Perception, Cadence M. Baker

Western Research Forum

Background: Magnetophosphenes are classified as colourless, flickering lights that are perceived with closed eyes in the dark, and upon exposure to a magnetic field (MF). Uncertainties exist involving the MF threshold for magnetophosphene perception.

Methods: Forty subjects will be enrolled in this experiment aiming to provide a frequency-response curve of magnetophosphene perception under MF exposure. Subjects will sit in a whole head MF exposure device wearing a 64-channel MRI-compatible EEG cap. Subjects will be exposed to a MF with a frequency of 5-300 Hz, in the form of an increasing flux density ramp (increasing magnetic field flux density from 0-100 …

Children With Moderate To Severe Cerebral Palsy May Not Benefit From Stochastic Vibration When Developing Independent Sitting, Anastasia Kyvelidou, Regina T. Harbourne, Joshua L. Haworth, Kendra K. Schmid, Nicholas Stergiou

Journal Articles

Purpose: Determine sitting postural control changes for children with cerebral palsy (CP), using a perceptual-motor intervention and the same intervention plus stochastic vibration through the sitting surface. Methods: Two groups of children with moderate or severe CP participated in the 12 week interventions. The primary outcome measure was center of pressure data from which linear and nonlinear variables were extracted and the gross motor function measure (GMFM). Results: There were no significant main effects of intervention or time or an interaction. Both treatment groups increased the Lyapunov exponent values in the medial–lateral direction three months after the …

Walking To A Multisensory Beat, Charlotte Roy, Julien Lagarde, Dobromir Dotov, Simone Dalla Bella

Journal Articles

Living in a complex and multisensory environment demands constant interaction between perception and action. In everyday life it is common to combine efficiently simultaneous signals coming from different modalities. There is evidence of a multisensory benefit in a variety of laboratory tasks (temporal judgement, reaction time tasks). It is less clear if this effect extends to ecological tasks, such as walking. Furthermore, benefits of multimodal stimulation are linked to temporal properties such as the temporal window of integration and temporal recalibration. These properties have been examined in tasks involving single, non-repeating stimulus presentations. Here we investigate the same temporal properties …

Design Of An Instrumented Cane For Real-Time Force Feedback, Samantha Sack

UNO Student Research and Creative Activity Fair

Stroke is a major cause of adult disability in the United States, and many affected stroke survivors require the use of an assistive device post-stroke. Even so, the effects of these assistive devices on specific movement outcomes like propulsion in rehabilitation are not well studied. The goal of this study was to develop an instrumented cane capable of recording accurate force data and providing real-time feedback to the user. A standard, single-point cane was instrumented with a force cell that measures force applied to the cane and a motor that vibrates once a threshold value has been applied. The force …

Movement Variability And Sensorimotor Cortical Activation During Forward And Backward Walking, Boman Groff

UNO Student Research and Creative Activity Fair

Previous research has used functional near-infrared spectroscopy (fNIRS) to show that motor areas of the cortex are activated more while walking backward compared to walking forward. It is also known that head movement creates motion artifacts in fNIRS data. The aim of this study was to expand on previous findings by examining cortical activation during forward and backward walking, while also measuring head movement. We hypothesized that greater activation in motor areas while walking backward would be concurrent with increased head movement.

Participants (N=8) performed forward and backward walking on a treadmill. Participants wore motion capture markers on their head …

Quantifying Static And Dynamic Stability Using Mobile Sensors, Mason Schleu

UNO Student Research and Creative Activity Fair

Balance disorders impact millions of people causing substantial impact on quality of life due to psychological and physical hardships associated with poor balance. However, a clinically relevant, low cost, self-service system in detecting such disorders does not exist. Previous research has shown the built in accelerometer and gyroscope sensors of a smart phone to be valid tools in detecting standing balance performance using traditional linear analysis, however, such a system has yet to be proven useful in detecting dynamic postural variability. Indeed, more quantitative methods than are typically used in clinical settings are necessary for early detection of poor postural …

An Investigation Into The Correlation Between Step Width Variability And Balance Deficits In Patients With Chronic Obstructive Pulmonary Disease, Jordan Freeman

UNO Student Research and Creative Activity Fair

Patients with chronic obstructive pulmonary disease (COPD) experience a higher incidence of falls. Further, gait variability has been shown to be a useful predictor of future falls. It is unknown if balance measures and gait variability are related. Our purpose was to investigate if step width (SW) variability is related to balance deficits in patients with COPD. We hypothesized that functional balance tests will closely correlate to the step width variability as compared to subjective balance questionnaires. Nine subjects with COPD and six controls performed a series of balance measures: sensory organization test (SOT), motor control test (MCT), Fullerton advanced …

The Effect Of Bilateral Vestibular Stimulation On Locomotor Adaptation, Allison Hoover

UNO Student Research and Creative Activity Fair

Locomotor adaptation requires input from vision, somatosensory and vestibular systems. The contribution of the vestibular system is important for maintaining postural control during gait specifically orientation of the head on the trunk and acceleration (linear and angular) feedback. Disrupting this system causes instabilities during locomotion. However, it is not clear, how much the vestibular system contributes to gait adaptation. Eighteen healthy adults adapted to a split-belt treadmill task with or without additional vestibular perturbation using bilateral mastoid vibration. The symmetry index for step length and step time, as well as the change in standard deviation in stride time for both …

Augmenting Human Muscle Performance Through Added Foot Stiffness, Samuel F. Ray

UNO Student Research and Creative Activity Fair

In human walking, the relationship between foot and ankle structure and function is not fully known. The foot and toe structures seem to dissipate energy while the ankle generates force through the plantarflexor muscles. Increasing foot stiffness through added carbon fiber insoles has been shown to increase force output and decrease contraction velocity of the ankle plantarflexor muscles. This shift in the muscular force-velocity operating range may be beneficial in fast walking. During fast walking, muscle fascicles contract at high velocities and low force output. We predict that added foot stiffness can reduce the metabolic cost of fast walking by …

A Comparison Of Balance Between A Smoker And Never-Smoker, Robert J. Barber

UNO Student Research and Creative Activity Fair

“Chronic obstructive pulmonary disease (COPD) the third leading cause of death in the United States.” “While COPD is defined in terms of fixed airflow limitation, it’s also characterized by the frequent association of complications outside the lung, including compromised balance.” Research has shown “medio-lateral (i.e., side-to-side) balance is altered in patients with COPD compared to controls and is further affected by challenging sensory systems (e.g., eyes closed or uneven surface).” “Smoking increases risk for onset of COPD”, therefore the objective of this study was to investigate balance in smokers. It’s hypothesized that smokers will demonstrate balance deficits, compared to never-smokers. …

Influence Of Neuromuscular Fatigue On The Reliability Of Gait Variability Measures, Nicholas Reynolds

UNO Student Research and Creative Activity Fair

Walking in healthy young adults displays an optimal pattern of variability from one stride to the next. This level ensures that each step taken is not stereotyped but also not completely unpredictable. Previous studies have investigated differences in stride-to-stride characteristics comparing groups of young to groups of elderly. The consistency of gait variability measures on an individual level remains to be determined. The first aim of this study is to determine the between day and between trial consistency of gait variability measures in healthy young adults. We hypothesize that there will be a high level of consistency from day-to-day and …

Effects Of Serial Subtractions On Elderly Gait Speed In A Virtual Reality Setting, Taylor Leeder

UNO Student Research and Creative Activity Fair

Falls are the leading cause of fatal injuries in older adults aged 65+ with one in three adults falling each year. Cognitive processes are involved in gait, and thus, as cognitive changes are normative with age, this may impact fall risk in the elderly. Sixteen older adults aged 70.8±5.3 years took part in a dual-task (DT) study where they walked on a split-belt self-paced treadmill with and without a virtual reality (VR) setting while simultaneously performing a serial subtraction (SS) task. For SS, individuals were given a random 3-digit starting number and told to subtract by three from that number …

Treadmill Walking In Claudication, Shane Lentz

UNO Student Research and Creative Activity Fair

INTRO. Claudication is lower leg pain that resides with rest. There are two potential causes of claudication: Peripheral Arterial Disease (PAD) and Lumbar Spinal Stenosis (LSS). Vasculogenic claudication is the defining characteristic of PAD. There is little research that exists to differentiate the two forms of claudication and there is little no non-invasive to determine which condition is causing the claudication. The purpose of this study is to utilize biomechanics to distinguish between individuals with claudication that arises from neurogenic versus vasculogenic causes. METHODS. Four LSS subjects completed a walking test on a treadmill (Gardner Test). The treadmill is pressure …

An Investigation In Muscle Activation During Load Carrying, Sidney Baudendistel

UNO Student Research and Creative Activity Fair

Carrying items is essential to everyday living, but is often reported to be a functional limitation in individuals with respiratory dysfunction. The interaction between breathing and carrying a bimanual load (i.e., carrying an evenly distributed load in each hand) is not well understood and limits the capacity to derive interventions to address functional limitations. The purpose of this study was to examine the effect of two bimanual loads, 10% and 5% of body weight, on gait. Fourteen healthy, young adults walked with and without a load on each wrist (2.5 and 5% of body weight) using wrist weights. The mean, …

Turning Performance Of Brief Squid Lolliguncula Brevis During Attacks On Shrimp And Fish, Rachel A. Jastrebsky, Ian K. Bartol, Paul S. Krueger

Biological Sciences Faculty Publications

Although squid are generally considered to be effective predators, little is currently known of how squid maneuver and position themselves during prey strikes. In this study, high-speed video and kinematic analyses were used to study attacks by the brief squid Lolliguncula brevis on both shrimp and fish. Squid attack successwas high (>80%) and three behavioral phases were identified: (1) approach, (2) strike and (3) recoil. Lolliguncula brevis demonstrated greater maneuverability (i.e. a smaller length-specific turning radius) and employed more body adjustments (i.e. mantle angle posturing) during approaches toward shrimp versus fish. Squid exhibited higher linear approach/strike velocities and accelerations …

Mastoid Vibration Affects Dynamic Postural Control During Gait In Healthy Older Adults, Jung Hung Chien, Mukul Mukherjee, Jenny Kent, Nick Stergiou

Journal Articles

Vestibular disorders are difficult to diagnose early due to the lack of a systematic assessment. Our previous work has developed a reliable experimental design and the result shows promising results that vestibular sensory input while walking could be affected through mastoid vibration (MV) and changes are in the direction of motion. In the present paper, we wanted to extend this work to older adults and investigate how manipulating sensory input through mastoid vibration (MV) could affect dynamic postural control during walking. Three levels of MV (none, unilateral, and bilateral) applied via vibrating elements placed on the mastoid processes were combined …