Doctor of Philosophy, University of Calgary (2023)
Master of Science, University of Calgary (2018)
Bachelor of Science, Queen's University (2015)
PhD, University of Calgary, Biomedical Engineering (2023)
MSc, University of Calgary, Biomechanics (2018)
BSc, Queen's University, Kinesiology (2015)
Feliks Kogan, Postdoctoral Faculty Sponsor
Sex disparities in tibia-fibula geometry and density are associated with elevated bone strain in females: A cross-validation study
2023; 173: 116803
Females are up to four times more likely to sustain a stress fracture than males. Our previous work, using statistical appearance modeling in combination with the finite element method, suggested that sex-related differences in tibial geometry may increase bone strain in females. The purpose of this study was to cross-validate these findings, by quantifying sex-related differences in tibia-fibula bone geometry, density, and finite element-predicted bone strain in a new cohort of young physically active adults. CT scans of the lower leg were collected for fifteen males (23.3 ± 4.3 years, 1.77 ± 0.09 m, 75.6 ± 10.0 kg) and fifteen females (22.9 ± 3.0 years, 1.67 ± 0.07 m, 60.9 ± 6.7 kg). A statistical appearance model was fit to each participant's tibia and fibula. The average female and male tibia-fibula complex, controlled for isotropic scaling, were then calculated. Bone geometry, density, and finite element-predicted bone strains in running were compared between the average female and male. The new cohort illustrated the same patterns as the cohort from the previous study: the tibial diaphysis of the average female was narrower and had greater cortical bone density. Peak strain and the volume of bone experiencing ≥4000 με were 10 % and 80 % greater, respectively, in the average female when compared to the average male, which was driven by a narrower diaphysis. The sex-related disparities in tibial geometry, density, and bone strain described by our previous model were also observed in this entirely new cohort. Disparities in tibial diaphysis geometry likely contribute to the elevated stress fracture risk observed in females.
View details for DOI 10.1016/j.bone.2023.116803
View details for Web of Science ID 001001540100001
View details for PubMedID 37201675
Statistical Shape Modelling Discriminates Patients with Complete Subtrochanteric and Midshaft Atypical Femoral Fractures
WILEY. 2023: 110
View details for Web of Science ID 001008985200324
Stride frequency derived from GPS speed fluctuations in galloping horses.
Journal of biomechanics
2022; 145: 111364
Changes in gallop stride parameters prior to injury have been documented previously in Thoroughbred racehorses. Validating solutions for quantification of fundamental stride parameters is important for large scale studies investigating injury related factors. This study describes a fast Fourier transformation-based method for extracting stride frequency (SF) values from speed fluctuations recorded with a standalone GPS-logger suitable for galloping horses. Limits of agreement with SF values derived from inertial measurement unit (IMU) pitch data are presented. Twelve Thoroughbred horses were instrumented with a GPS-logger (Vbox sport, Racelogic, 10 Hz samplerate) and a IMU-logger (Xsens DOT, Xsens, 120 Hz samplerate), both attached to the saddlecloth in the midline caudal to the saddle and time synchronized by minimizing root mean square error between differentiated GPS and IMU heading. Each horse performed three gallop trials with a target speed of 36miles per hour (16.1 ms-1) on a dirt racetrack. Average speed was 16.48 ms-1 ranging from 16.1 to 17.4 ms-1 between horses. Limits of agreement between GPS- and IMU-derived SF had a bias of 0.0032 Hz and a sample-by-sample precision of +/-0.027 Hz calculated over N = 2196 values. The stride length uncertainty related to the trial-by-trial SF precision of 0.0091 Hz achieved across 100 m gallop sections is smaller than the 10 cm decrease in stride length that has been associated with an increased risk of musculoskeletal injury. This suggests that the described method is suitable for calculating fundamental stride parameters in the context of injury prevention in galloping horses.
View details for DOI 10.1016/j.jbiomech.2022.111364
View details for PubMedID 36343415
Tibial-fibular geometry and density variations associated with elevated bone strain and sex disparities in young active adults
2022; 161: 116443
Tibial stress fracture is a common injury in runners and military personnel. Elevated bone strain is believed to be associated with the development of stress fractures and is influenced by bone geometry and density. The purpose of this study was to characterize tibial-fibular geometry and density variations in young active adults, and to quantify the influence of these variations on finite element-predicted bone strain. A statistical appearance model characterising tibial-fibular geometry and density was developed from computed tomography scans of 48 young physically active adults. The model was perturbed ±1 and 2 standard deviations along each of the first five principal components to create finite element models. Average male and female finite element models, controlled for scale, were also generated. Muscle and joint forces in running, calculated using inverse dynamics-based static optimization, were applied to the finite element models. The resulting 95th percentile pressure-modified von Mises strain (peak strain) and strained volume (volume of elements above 4000 με) were quantified. Geometry and density variations described by principal components resulted in up to 12.0% differences in peak strain and 95.4% differences in strained volume when compared to the average tibia-fibula model. The average female illustrated 5.5% and 41.3% larger peak strain and strained volume, respectively, when compared to the average male, suggesting that sexual dimorphism in bone geometry may indeed contribute to greater stress fracture risk in females. Our findings identified important features in subject-specific geometry and density associated with elevated bone strain that may have implications for stress fracture risk.
View details for DOI 10.1016/j.bone.2022.116443
View details for Web of Science ID 000804091100005
View details for PubMedID 35589067
A statistical shape model of the tibia-fibula complex: sexual dimorphism and effects of age on reconstruction accuracy from anatomical landmarks
COMPUTER METHODS IN BIOMECHANICS AND BIOMEDICAL ENGINEERING
2022; 25 (8): 875-886
A statistical shape model was created for a young adult population and used to predict tibia and fibula geometries from bony landmarks. Reconstruction errors with respect to CT data were quantified and compared to isometric scaling. Shape differences existed between sexes. The statistical shape model estimated tibia-fibula geometries from landmarks with high accuracy (RMSE = 1.51-1.62 mm), improving upon isometric scaling (RMSE = 1.78 mm). Reconstruction errors increased when the model was applied to older adults (RMSE = 2.11-2.17 mm). Improvements in geometric accuracy with shape model reconstruction changed hamstring moment arms 25-35% (1.0-1.3 mm) in young adults.
View details for DOI 10.1080/10255842.2021.1985111
View details for Web of Science ID 000714280100001
View details for PubMedID 34730046
Are subject-specific models necessary to predict patellar tendon fatigue life? A finite element modelling study
COMPUTER METHODS IN BIOMECHANICS AND BIOMEDICAL ENGINEERING
2022; 25 (7): 729-739
Patellar tendinopathy is an overuse injury that occurs from repetitive loading of the patellar tendon in a scenario resembling that of mechanical fatigue. As such, fatigue-life estimates provide a quantifiable approach to assess tendinopathy risk and may be tabulated using nominal strain (NS) or finite element (FE) models with varied subject-specificity. We compared patellar tendon fatigue-life estimates from NS and FE models of twenty-nine athletes performing countermovement jumps with subject-specific versus generic geometry and material properties. Subject-specific patellar tendon material properties and geometry were obtained using a data collection protocol of dynamometry, ultrasound, and magnetic resonance imaging. Three FE models were created for each subject, with: subject-specific (hyperelastic) material properties and geometry, subject-specific material properties and generic geometry, and generic material properties and subject-specific geometry. Four NS models were created for each subject, with: subject-specific (linear elastic) material properties and moment arm, generic material properties and subject-specific moment arm, subject-specific material properties and generic moment arm, and generic material properties and moment arm. NS- and FE-modelled fatigue-life estimates with generic material properties were poorly correlated with their subject-specific counterparts (r2≤0.073), while all NS models overestimated fatigue life compared to the subject-specific FE model (r2≤0.223). Furthermore, FE models with generic tendon geometry were unable to accurately represent the heterogeneous strain distributions found in the subject-specific FE models or those with generic material properties. These findings illustrate the importance of incorporating subject-specific material properties and FE-modelled strain distributions into fatigue-life estimations.
View details for DOI 10.1080/10255842.2021.1975683
View details for Web of Science ID 000695066700001
View details for PubMedID 34514910
Lower-limb joint kinetics in jump rope skills performed by competitive athletes
The purpose of this study was to characterise lower-limb joint kinetics during consecutive double unders and speed step sprints performed by competitive jump rope athletes, and to compare these measurements to running. Sixteen adolescent competitive jump rope athletes performed consecutive double under, speed step, and running trials while motion capture and ground reaction force data were collected. Lower-limb joint moments, power, and work were calculated using an inverse dynamics approach and discrete measurements were compared between skills. Peak ground reaction forces were similar between movements; however, knee and hip joint kinetics were distributed differently between double unders and speed step. In general, double unders were characterised by an increased reliance on knee joint kinetics, while speed step was characterised by an increased reliance on hip joint kinetics. Peak ankle moments were 9-20% greater in speed step when compared to double unders and running (p ≤ 0.050), and peak negative ankle power was 39-114% greater in double unders and speed step when compared to running (p ≤ 0.002). These findings may have important implications for injury risk and load management in jump rope athletes or other individuals that incorporate jump rope into their training programs.
View details for DOI 10.1080/14763141.2020.1801823
View details for Web of Science ID 000567041600001
View details for PubMedID 32857016
Effect of Shoe and Surface Stiffness on Lower Limb Tendon Strain in Jumping
MEDICINE AND SCIENCE IN SPORTS AND EXERCISE
2019; 51 (9): 1895-1903
Tendinopathies are painful overuse injuries observed in athletes participating in jumping sports. These injuries are heavily dependent on the resulting strain from the applied mechanical load. Therefore, mechanisms to reduce tendon strain may represent a primary prevention strategy to reduce the incidence of tendinopathy.The purpose of this study was to examine the effect of shoe and surface stiffness on Achilles and patellar tendon strains during jumping. We hypothesized that less stiff shoes and surfaces would reduce Achilles and patellar tendon strains during jumping.Thirty healthy male basketball players performed countermovement jumps in three shoes and on three surfaces with different stiffness properties while motion capture, force platform, and jump height data were collected. Magnetic resonance imaging was used to obtain participant-specific tendon morphology, and a combined dynamometry/ultrasound/electromyography session was used to obtain tendon material properties. Finally, a musculoskeletal model was used to estimate tendon strains in each surface and shoe combination.Achilles tendon strains during landing were reduced by 5.3% in the least stiff shoe compared with the stiffest shoe (P = 0.021) likely due to in bending stiffness altering the center of pressure location. Furthermore, Achilles tendon strains during landing were 5.7% and 8.1% lower on the stiffest surface compared with the least stiff and middle stiffness surfaces, respectively (P ≤ 0.047), because of changes in ground reaction force magnitude and center of pressure location. No effects of shoe stiffness or surface construction were observed for jump height (P > 0.243) or peak patellar tendon strains (P > 0.259).Changes to shoe stiffness and surface construction can alter Achilles tendon strains without affecting jump performance in athletes.
View details for DOI 10.1249/MSS.0000000000002004
View details for Web of Science ID 000484228600013
View details for PubMedID 30973480
- Effects of basketball court construction and shoe stiffness on countermovement jump landings FOOTWEAR SCIENCE 2019; 11 (3): 171-179
Principal components analysis to characterise fatigue-related changes in technique: Application to double under jump rope
JOURNAL OF SPORTS SCIENCES
2017; 35 (13): 1300-1309
The upper extremities play an important role in managing the rope-turning technique required to perform continuous double unders. However, acute adaptions in this technique may occur as a jumper fatigues. The purpose of this study was to examine how turning technique is adapted with fatigue. Three-dimensional kinematic data of the upper extremity were collected from 10 trained athletes as they performed consecutive double unders to volitional fatigue. Time series wrist, elbow and shoulder joint angles were calculated where joint angle waveforms representing 10 unique trials from the beginning ("fresh") and end ("fatigued") of the continuous jumping protocol for all participants were analysed using principal component analysis. Participants reported stopping due to cardiovascular and shoulder muscular fatigue. From a kinematics perspective, with fatigue athletes used a more internally rotated range of motion at the shoulder, which we believe prompted a series of more distal adaptions in order to maintain rope turning, preserving consecutive double under performance. The presence of a maladaptive adaptation at the shoulder may increase the risk of developing shoulder injuries. Coaches should consider helping jumpers develop appropriate shoulder muscle endurance such that they can continue to maximise their training and proficiency, while protecting against potential fatigue-related maladaptation.
View details for DOI 10.1080/02640414.2016.1221523
View details for Web of Science ID 000399248600012
View details for PubMedID 27556961