Olivia Bruce

All Publications

• Predicting Tibia-Fibula Geometry and Density From Anatomical Landmarks Via Statistical Appearance Model: Influence of Errors on Finite Element-Calculated Bone Strain. Journal of biomechanical engineering Bruce, O., Tu, J., Edwards, W. B. 2024: 1-32

  Abstract

  State-of-the-art participant-specific finite element models require advanced medical imaging to quantify bone geometry and density distribution; access to and cost of imaging is prohibitive to the use of this approach. Statistical appearance models may enable estimation of participants' geometry and density in the absence of medical imaging. The purpose of this study was to: (1) quantify errors associated with predicting tibia-fibula geometry and density distribution from skin-mounted landmarks using a statistical appearance model and (2) quantify how those errors propagate to finite element-calculated bone strain. Participant-informed models of the tibia and fibula were generated for thirty participants from height and sex, and from twelve skin-mounted landmarks using a statistical appearance model. Participant-specific running loads, calculated using gait data and a musculoskeletal model, were applied to participant-informed and CT-based models to predict bone strain using the finite element method. Participant-informed meshes illustrated median geometry and density distribution errors of 4.39-5.17 mm and 0.116-0.142 g/cm3, respectively, resulting in large errors in strain distribution (median RMSE = 476-492 μεe), peak strain (limits of agreement = ± 27-34%), and strained volume (limits of agreement = ± 104-202%). These findings indicate that neither landmark nor height and sex-based predictions could adequately approximate CT-derived participant-specific geometry, density distribution, or finite element-predicted bone strain and therefore should not be used for analyses comparing between groups or individuals.

  View details for DOI 10.1115/1.4065216

  View details for PubMedID 38558117

• Fixed and Relative Positioning of Scans for High Resolution Peripheral Quantitative Computed Tomography. Journal of clinical densitometry : the official journal of the International Society for Clinical Densitometry Bugbird, A. R., Klassen, R. E., Bruce, O. L., Burt, L. A., Edwards, W. B., Boyd, S. K. 2023; 27 (1): 101462

  Abstract

  High resolution peripheral quantitative computed tomography (HR-pQCT) imaging protocol requires defining where to position the ∼1 cm thick scan along the bone length. Discrepancies between the use of two positioning methods, the relative and fixed offset, may be problematic in the comparison between studies and participants. This study investigated how bone landmarks scale linearly with length and how this scaling affects both positioning methods aimed at providing a consistent anatomical location for scan acquisition.Using CT images of the radius (N = 25) and tibia (N = 42), 10 anatomical landmarks were selected along the bone length. The location of these landmarks was converted to a percent length along the bone, and the variation in their location was evaluated across the dataset. The absolute location of the HR-pQCT scan position using both offset methods was identified for all bones and converted to a percent length position relative to the HR-pQCT reference line for comparison. A secondary analysis of the location of the scan region specifically within the metaphysis was explored at the tibia.The location of landmarks deviated from a linear relationship across the dataset, with a range of 3.6 % at the radius sites, and 4.5 % at the tibia sites. The consequent variation of the position of the scan at the radius was 0.6 % and 0.3 %, and at the tibia 2.4 % and 0.5 %, for the fixed and relative offset, respectively. The position of the metaphyseal junction with the epiphysis relative to the scan position was poorly correlated to bone length, with R2 = 0.06 and 0.37, for the fixed and relative offset respectively.The variation of the scan position by either method is negated by the intrinsic variation of the bone anatomy with respect both to total bone length as well as the metaphyseal region. Therefore, there is no clear benefit of either offset method. However, the lack of difference due to the inherent variation in the underlying anatomy implies that it is reasonable to compare studies even if they are using different positioning methods.

  View details for DOI 10.1016/j.jocd.2023.101462

  View details for PubMedID 38104525

• Sex disparities in tibia-fibula geometry and density are associated with elevated bone strain in females: A cross-validation study BONE Bruce, O. L., Edwards, W. 2023; 173: 116803

  Abstract

  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 Bruce, O., Haider, I., Cheung, A., Edwards, W. WILEY. 2023: 110

  View details for Web of Science ID 001008985200324

• Stride frequency derived from GPS speed fluctuations in galloping horses. Journal of biomechanics Pfau, T., Bruce, O., Brent Edwards, W., Leguillette, R. 2022; 145: 111364

  Abstract

  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 BONE Bruce, O. L., Baggaley, M., Khassetarash, A., Haider, I. T., Edwards, W. 2022; 161: 116443

  Abstract

  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 Bruce, O. L., Baggaley, M., Welte, L., Rainbow, M. J., Edwards, W. 2022; 25 (8): 875-886

  Abstract

  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 Firminger, C. R., Haider, I. T., Bruce, O. L., Wannop, J. W., Stefanyshyn, D. J., Edwards, W. 2022; 25 (7): 729-739

  Abstract

  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 SPORTS BIOMECHANICS Bruce, O. L., Ramsay, M., Kennedy, G., Edwards, W. 2020: 1-14

  Abstract

  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 Firminger, C. R., Bruce, O. L., Wannop, J. W., Stefanyshyn, D. J., Edwards, W. 2019; 51 (9): 1895-1903

  Abstract

  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 Bruce, O. L., Firminger, C. R., Wannop, J. W., Stefanyshyn, D. J., Edwards, W. 2019; 11 (3): 171-179

  View details for DOI 10.1080/19424280.2019.1668867

  View details for Web of Science ID 000497991200006

• Principal components analysis to characterise fatigue-related changes in technique: Application to double under jump rope JOURNAL OF SPORTS SCIENCES Bruce, O., Moull, K., Fischer, S. 2017; 35 (13): 1300-1309

  Abstract

  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