Biomechanics Commons^™

Concussion-Related Symptomatology And Outcomes In Individuals With Mental Health Conditions: Symptom Number And Severity, Balance Performance, And Time Course To Discharge, Kathryn J. Schulze

Electronic Thesis and Dissertation Repository

Symptomatology can overlap between concussions and common mental health conditions (MHCs) – such as anxiety, depression, and attention-deficit/hyperactivity disorder. Research determined that there can be an onset of new or worsening symptoms related to pre-existing MHCs in individuals post-concussion. Pre-existing MHCs may affect concussion outcomes. Therefore, the relationship between pre-existing MHCs and concussions was further examined. Study One examined the difference in symptom severity and number of symptoms reported at the initial clinical assessment for concussion for individuals with and without a pre-existing MHC. A chart review determined that individuals with anxiety or multiple MHCs had significantly more concussion symptoms …

The Influence Of Knee Position And Sex On Ultrasound Imaging Of Femoral Cartilage Characteristics, Harry Battersby

Electronic Thesis and Dissertation Repository

The purpose was to examine (1) the effect of measurement position and sex on femoral cartilage outcomes, and (2) the association between gait biomechanics and cartilage outcomes. Fifty individuals participated (25 males, 25 females; Age=20.62±1.80years). Ultrasound measured femoral cartilage thickness and echo-intensity (EI) at 90º, 115º, and 140º of knee flexion. Gait outcomes included the external knee adduction and knee flexion moments. Cartilage outcomes were compared using 2(sex) x 3(position) repeated measures ANOVA. Gait and cartilage associations were assessed using stepwise regression. Cartilage was thicker when measured at 90° compared with 140°, but mainly in males. Males had thicker cartilage …

Reliability And Validity Of The Onpoint System For Quantifying Performance Of The Star Excursion Balance Test, Adam Redgrift

Undergraduate Student Research Internships Conference

The Star Excursion Balance Test (SEBT) is a clinical method of assessing dynamic balance in healthy adults and athletes1. Furthermore, this functional test may be extended to the examination of lower extremity injury, such as ankle instability, in injured populations2. The ‘ONPoint System’ is a tool developed by Dr. Jacob Reeves, which attempts to reduce barriers for clinicians seeking to use the SEBT. Before widespread implementation, the ONPoint system must first be examined in terms of both its validity and reliability. To do this, measurements taken from the OnPoint mat were compared to data obtained from a pressure mapping device, …

The Impact Of Impacts: Repetitive Head Impact Exposure In Canadian University Football Players, Jeffrey S. Brooks

Electronic Thesis and Dissertation Repository

Due to the physical nature of the game and repeated head impacts between players each play, the sport of football has one of the highest incidence rates of concussion. With nearly two million participants, this incidence rate translates to a reserved estimate of 100,000 concussions per year due to the contact nature of the sport. Injury thresholds have proven difficult to establish, so American football concussion research has shifted focus to measuring the accumulation of repetitive head impacts. As there are numerous rule differences between Canadian and American football, head impact exposure may present differently for Canadian players. Accordingly, the …

Comparison Of Whole-Body Vibration Attenuation Properties Between Active And Passive Suspension Seats, Ben Dietze

Electronic Thesis and Dissertation Repository

Professional drivers are at a high risk of WBV injury as they are exposed to vibration constantly throughout a working day. Recently a company has attempted to mitigate the risk by developing an active suspension seat aimed at reducing WBV exposure for long haul truck drivers. The purpose of this thesis was to compare the new active suspension technology to the current industry standard passive suspension seat. Seats were tested with Random vibration exposures and exposures simulating Canadian long-haul trucks. Seats were evaluated by A(8) daily vibration exposure and peak transmissibility metrics. The results determined that the active suspension is …

Does An Acute Achilles Tendon Rupture Become A Patient's Achilles Heel In The Long-Term?, Michaela Cm Khan

Electronic Thesis and Dissertation Repository

It is unknown if deficits in the involved limb following acute Achilles tendon rupture (AATR) persist in the long-term, or differ between patients treated operatively or non-operatively. This study investigated 43 patients 15±1 years post-AATR from a previous randomized controlled trial (RCT) that compared operative and non-operative treatment. Structural characteristics in the Achilles tendon and surrounding musculature were assessed using magnetic resonance imaging. We also performed physical examinations and evaluated performance-based and patient-reported outcomes. Overall, there were substantial differences between the involved and uninvolved limbs in most outcomes. Some outcomes improved over time from the initial RCT to the final …

Strains In Regions Of The Brain Modelled From Female Youth Soccer Players Performing Purposeful Headers In Season, Wayne Allison

Electronic Thesis and Dissertation Repository

Soccer is the world's most popular sport, and intentional heading of the ball is exclusive to it. Head impacts in youth players are riskier than adults as their brains are developing. Finite element models can quantify parameters, like strains within regions of the brain, that are otherwise difficult to assess. The purpose of this stay was to examine the relationship between head kinematics collected by wireless head impact sensors and brain strains in regions of interest related to concussion. As well, we assessed head impact strains in regions of interest related to concussion for headers from various game scenarios. In …

Quantitative Analysis Of The Kinematics Of The Foot During Gait With Respect To Barefoot Running Shoes Using A Multi-Segment Foot Model, Lisa Y. Oikawa

Electronic Thesis and Dissertation Repository

Kinematics of the foot during static and dynamic tasks are technically challenging to accurately measure, making it difficult to evaluate their contribution to running-related injuries. Motion capture can detect changes in running mechanics, such as with differing footwear. Habitual barefoot runners and/habitual minimalist shoe runners underwent a biomechanical evaluation of their foot movement during running using reflective markers and optical motion capture. A five-segment foot model was used to compare motions between the different parts of the foot while running barefoot and wearing Vibram Five Fingers™ (VFF) barefoot mimicking shoes. Supination/pronation in the forefoot was larger but not significant between …

Measuring Quality Of Life In Patients With Rotator Cuff Disorders, Rochelle Furtado

Electronic Thesis and Dissertation Repository

Rotator cuff disorders (RCDs) are a common musculoskeletal problem with a higher prevalence in women and after the age of 60. Due to the increasing need for patient-centered care, researchers have been directed towards the use of patient reported outcomes (PROs) to evaluate the progress of patient recovery, as the experience varies across individuals.

Recently, the Western Ontario Rotator Cuff Index was reduced in items to create the shortened version of the Western Ontario Rotator Cuff Index (Short-WORC). However, the Short-WORC’s psychometrics have yet to be evaluated. Therefore, this mixed-methods thesis aimed to evaluate the psychometric properties of the Short-WORC …

Head Impact Exposures In Youth Canadian Football Players Aged 12-14 Do Not Significantly Impair Antisaccade Performance, William J. Smith

Electronic Thesis and Dissertation Repository

There is a growing body of research evaluating head impacts in sport, but studies have not evaluated youth football in Canada. It is important to evaluate football in Canada as the rules and field size are different than American football, and this may influence the impact exposures. The purpose of this study was to quantify the head impact exposures in youth Canadian football and determine if a season’s worth of impacts could cause impairments in executive function. Players (n=50) had their head impacts recorded using an impact measuring device (GForceTracker) throughout all contact practices and games. A subset of players …

Performance Impact Of Different Lower-Limb Setup Positions In The Backstroke Swimming Start, Gordon E. Barkwell

Electronic Thesis and Dissertation Repository

The performance impact of different knee extension angles in the setup position for a backstroke start was evaluated using an instrumented starting surface. Ten backstroke swimmers completed maximum-effort starts in each of two setup positions: one with the knees flexed, and one with the knees extended. The start handles and touchpad were instrumented with tri-axial force plates. Activity of major hip and knee extensors was measured using surface electromyography. Body position was recorded throughout the start using two high-speed cameras. There was no difference in time to 10 m between the two conditions, indicating there is likely no advantage in …

Motor Variability In Rowing, Maude Potvin-Gilbert

Electronic Thesis and Dissertation Repository

The aim of the study was to analyze the impact of environment, intensity and distance rowed on temporal variability of strokes and on knee angle variability. 11 participants rowed 2,000 m at high and low intensities on an ergometer and at high intensity in a single on-water. Data were collected at the beginning and at the end of each exercise. All the factors influenced significantly the temporal variability (respectively beta=-0.013 and p .007=; beta= 0.007 and p=.021; beta=0.06 and p=.028). The difference of visual information and the need of the rower to adapt to environmental factors might explain …

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 …

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 …

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 …

The Use Of P3b As An Indicator Of Neurophysiologic Change From Subconcussive Impacts In Football Players, Jeffrey S. Brooks

Electronic Thesis and Dissertation Repository

There is a growing appreciation in research that subconcussive impacts may affect cognitive functioning. Canadian University football players (n=45) were separated into three groups based on their position/skill (small skilled, big skilled and big unskilled). An impact measuring device (GForceTracker) was used to record the number of impacts that each player experienced in a season. Player groups were separated into two levels of impact exposure: low and high. Players completed baseline, midseason, postseason, and follow-up neurophysiological tests (four months later) to measure P3b amplitude in response to a visual oddball paradigm, and high versus low impact subgroups for each player …

The Effects Of Ice Hockey Goaltender Leg Pads On Safety And Performance, Ryan J. Frayne

Electronic Thesis and Dissertation Repository

Ice hockey goaltenders have the highest percentage of cam-type femoroacetabular impingement (FAI). The exact cause of these injuries in goaltenders remains unknown; however, it has been suggested that common goaltender movements and a goaltender’s underlying hip pathology may be contributing factors. The butterfly save technique, commonly used by goaltenders, has been linked to FAI. Simply stopping these movements would likely be detrimental to goaltender performance. Therefore, changing other aspects of goaltending, such as altering the goaltender equipment, should be considered. The overall objective of this thesis was to understand how ice hockey goaltender leg pads influence both the safety and …

Using An Aerial Drone To Examine Lateral Movement In Sweep Rowers, Joseph S. Munn

Electronic Thesis and Dissertation Repository

Rowing is a sport that is performed on the water, because of this there are many challenges associated with studying rowing. The primary challenges are an inability to control the environment and limitations with the equipment that can be used to collect data on the water. In order to try and overcome some of these challenges an aerial drone fitted with a high resolution camera was used to examine an understudied element of the rowing stroke, lateral movement in sweep rowers. Oar and shoulder angles and lateral movement of the shoulders and hands were calculated and compared between five different …

Constraining Kinematics During Single-Leg Squats And Step-Ups Can Reduce Quadratus Lumborum Activation And Facilitate Gluteal Activation, Shaylyn Kowalchuk

Electronic Thesis and Dissertation Repository

Increased quadratus lumborum activation and decreased gluteal activation may lead to lateral pelvic drop and increased hip adduction and internal rotation during single-leg exercises. These activation patterns and motions are associated with low back pain or lower extremity injuries. The purpose of this study was to evaluate if mechanically restricting hip adduction and internal rotation of the femur affected muscle activation. Twenty female track and field athletes performed single-leg squats and step-ups, and the quadratus lumborum, gluteus medius and maximus muscles activations were measured with surface electromyography. This study tested the hypothesis that mechanically restricted exercises would decrease quadratus lumborum …

Markerless Radiostereogammetry Of The Shoulder Joint In Humans: Comparisons Of Scapulohumeral Kinematics Between Individuals With Healthy And Supraspinatus-Impaired Shoulders, Ashley N. Hannon

Electronic Thesis and Dissertation Repository

The purpose of this collection of studies was to further develop the knowledge of shoulder motion in order to better understand joint function through direct measurement of 3D scapulohumeral joint kinematics using a technique of high accuracy. Markerless, bi-planar fluoroscopic radiostereometric analysis using a generic shoulder model was developed in this thesis, reducing the amount of radiation exposure to subjects. The studies compared kinematic data of the scapulohumeral joint in six degrees of freedom with a precise, in-vivo measuring technique. Data were collected on young and older healthy individuals, individuals with a torn supraspinatus and post-surgical intervention.

Although this generic …

A Comparative Analysis Of Softball Gloves: Catcher's Glove Yields Highest Peak Hand Pressure, Brittany M. Hicks

Electronic Thesis and Dissertation Repository

Catchers commonly develop abnormal blood flow in the ulnar artery, digital ischemia in the index finger, and index finger hypertrophy as a result of continual trauma to the hand. The hand sustains peak pressures that are much greater than the recommended thresholds for repetitive tasks. The objective of this study was to measure the peak pressure on the hand when catching a softball and to determine which glove type (catcher’s glove, first baseman’s glove or fielder’s glove) is most effective at reducing the peak pressure on the hand. Pressure data was collected using Tekscan pressure sensors. Results indicate the hand …

Factors Affecting Block Performance From The Omega Osb11 Starting Platform, Andrew Dragunas

Electronic Thesis and Dissertation Repository

In 2009, the international governing body of swimming approved the use of the Omega OSB11 platform. It features a back foot kick plate that can be shifted into five positions. The purpose of this thesis is to identify set stance characteristics of the track start that may produce a faster start from the OSB11. The first project evaluated: optimal kick plate location, its relationship to segment lengths, and rear foot position as high and low on the kick plate. The swimmers demonstrated significantly greater horizontal take-off velocity and decreased time to 2 m with the rear foot in the high …

Evaluation Of Suspension Seats Under Multi-Axis Vibration Excitations - A Neural Net Model Approach To Seat Selection, Xiaoxu Ji

Electronic Thesis and Dissertation Repository

Whole-body vibration describes vibrations that are transferred from a supporting surface to the human body. Low back injury is a major health issue amongst heavy machine operators and seat selection is important for reducing vibration exposure. Modeling the vibration attenuation properties of seats is one approach for predicting the performance of seats in different vibration environments. An efficient neural network (NN) algorithm identified the vibration attenuation properties of five suspension seats that are commonly used in the Northern Ontario mining sector. Each of the NN seat models strongly predicted vertical seatpan r.m.s. accelerations from the chassis accelerations and a measure …

Validation Of The Multi-Segment Foot Model With Bi-Planar Fluoroscopy, Aïda Valevicius

Electronic Thesis and Dissertation Repository

A multi-segment foot model (MSFM) is a useful tool for measuring foot joint kinematics although soft-tissue artefact is often present. Quantifying this error is needed to evaluate the accuracy of this model. This study validated the MSFM against bi-planar radiostereometric analysis (RSA) fluoroscopy. Heel-strike, mid-stance, and toe-off events during the stance phase were compared between motion capture and fluoroscopy. Rise/drop of the medial longitudinal arch showed a significant difference (p < 0.05) during toe-off, but no significant difference during heel-strike or mid-stance. Hindfoot supination/pronation and internal/external rotation, and forefoot supination/pronation motions showed no significant difference between the two techniques. The lack of significant difference will allow the MSFM to be used as a sufficiently accurate technique for measuring foot joint motions.

Evaluating The Similarity In Postures Between Forklift Operators In Virtual Reality And The Workplace, Youngmin Jun

Electronic Thesis and Dissertation Repository

Forklift operators must adopt awkward postures in order to gain appropriate lines of sight; these postures are associated with musculoskeletal injuries and disorders such as low back pain and neck pain. The purpose of this thesis was to evaluate the similarity in postures between forklift operators in virtual reality simulation of forklift loading and unloading operations and a corresponding real world workplace. This evaluation will help determine whether the virtual reality system is a useful tool for performing controlled laboratory-based investigations of ergonomics issues in heavy mobile machinery. One certified forklift operator and one uncertified individual performed two cycles of …

The Effects Of Oar-Shaft Stiffness And Length On Rowing Biomechanics, Brock Laschowski

Electronic Thesis and Dissertation Repository

This work investigates the effects of oar-shaft stiffness and length on rowing biomechanics. The mechanical properties of the oar-shafts were examined using an end-loaded cantilever system, and theoretical relations were proposed between the mechanics of the oar-shafts and rowing performance. On-water experiments were subsequently conducted and rowing biomechanics measured via the PowerLine Rowing Instrumentation System. The PowerLine system measures force and oar angle on the oarlock, as well as proper boat acceleration. The convergent validity and test-retest reliability of the PowerLine force measurements were determined prior to the on-water experiments. Thereafter, rowers were tested over a set distance using oar-shafts …

Comprehensive Analysis Of Abdominal Tendon Length:Muscle Length Ratios In Human And Rat Specimens, Alexander J. Stephen

Electronic Thesis and Dissertation Repository

Introduction: This study measured and described the tendon to muscle length ratios (TMRs) of the external oblique (EO), internal oblique (IO), rectus abdominus (RA), and transverse abdominus (TrA) muscles in humans and rats. Methods: The abdominal muscles of human and rat specimens were dissected and the length of the muscle fibers from their posterior attachments to the lumbodorsal fascia or the rib cage, and the lengths of their tendons, were measured. The tendon length was divided by muscle fiber length to calculate the TMR. Results: The TMRs for the human EO, IO, and TrA muscles were significantly larger than the …

Reliability And Validity Of Knee Moments: 3d Gait Analysis In Subjects With And Without Knee Osteoarthritis, Sara E. Richardson

Electronic Thesis and Dissertation Repository

Quantifying the reliability and validity of gait data in patients with knee osteoarthritis is required to more confidently evaluate effects of interventions and identify potential responders. 109 patients after high tibial osteotomy underwent 3-dimensional gait analysis consisting of four walking trials to calculate the external knee moments in three anatomical planes. The first two trials were compared to the second two trials to evaluate within-session test re-test reliability. 61 patients were matched to 61 healthy controls of similar age, sex and body mass index. Intraclass correlation coefficients were very high, ranging from 0.93 for peak knee adduction moment to 0.84 …

Neuromuscular Function Following Lengthening Contractions, Geoffrey A. Power

Electronic Thesis and Dissertation Repository

Unaccustomed lengthening contractions have been shown to impair muscle function - however little is known regarding this impairment on muscle power - specifically, the velocity component of power during voluntary contractions in humans. The four studies presented in my thesis investigated power-loss following lengthening contractions in healthy young and old women and young men.

The purpose of Study 1 was to determine reliability of velocity-dependent power of the dorsiflexors using the isotonic mode of the Biodex Dynamometer. I determined the isotonic mode is reliable and can be used to track changes in velocity and power following fatigue and lengthening contractions. …

Effect Of Sledge Hockey Configuration On Sledge Hockey Performance, Cliff Worden-Rogers

Electronic Thesis and Dissertation Repository

The purpose of this study was to evaluate the position of a sledge hockey player in their sledge using measurements of knee angle, seat height, and stability. Prior to this study, sledge hockey coaches and athletes used trivial methods to position a player in their seat. Proper positioning can enhance performance and function of the athlete. Nine different positions were evaluated using two on-ice sledge hockey specific tests. Four experienced male sledge hockey players from the London Blizzard who compete in the Ontario Sledge Hockey Association participated in this study. The results suggest a knee angle of 140º with a …