Browsing by Author "Baggaley, Michael"

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    Effect of stride length on the running biomechanics of healthy women of different statures
    (2023-07-24) Sundaramurthy, Aravind; Tong, Junfei; Subramani, Adhitya V.; Kote, Vivek; Baggaley, Michael; Edwards, W. B.; Reifman, Jaques
    Abstract Background Tibial stress fracture is a debilitating musculoskeletal injury that diminishes the physical performance of individuals who engage in high-volume running, including Service members during basic combat training (BCT) and recreational athletes. While several studies have shown that reducing stride length decreases musculoskeletal loads and the potential risk of tibial injury, we do not know whether stride-length reduction affects individuals of varying stature differently. Methods We investigated the effects of reducing the running stride length on the biomechanics of the lower extremity of young, healthy women of different statures. Using individualized musculoskeletal and finite-element models of women of short (N = 6), medium (N = 7), and tall (N = 7) statures, we computed the joint kinematics and kinetics at the lower extremity and tibial strain for each participant as they ran on a treadmill at 3.0 m/s with their preferred stride length and with a stride length reduced by 10%. Using a probabilistic model, we estimated the stress-fracture risk for running regimens representative of U.S. Army Soldiers during BCT and recreational athletes training for a marathon. Results When study participants reduced their stride length by 10%, the joint kinetics, kinematics, tibial strain, and stress-fracture risk were not significantly different among the three stature groups. Compared to the preferred stride length, a 10% reduction in stride length significantly decreased peak hip (p = 0.002) and knee (p < 0.001) flexion angles during the stance phase. In addition, it significantly decreased the peak hip adduction (p = 0.013), hip internal rotation (p = 0.004), knee extension (p = 0.012), and ankle plantar flexion (p = 0.026) moments, as well as the hip, knee, and ankle joint reaction forces (p < 0.001) and tibial strain (p < 0.001). Finally, for the simulated regimens, reducing the stride length decreased the relative risk of stress fracture by as much as 96%. Conclusions Our results show that reducing stride length by 10% decreases musculoskeletal loads, tibial strain, and stress-fracture risk, regardless of stature. We also observed large between-subject variability, which supports the development of individualized training strategies to decrease the incidence of stress fracture.
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    Effects of body size and load carriage on lower-extremity biomechanical responses in healthy women
    (2021-02-24) Unnikrishnan, Ginu; Xu, Chun; Baggaley, Michael; Tong, Junfei; Kulkarni, Sahil; Edwards, W. B.; Reifman, Jaques
    Abstract Background Musculoskeletal injuries, such as stress fractures, are the single most important medical impediment to military readiness in the U.S. Army. While multiple studies have established race- and sex-based risks associated with a stress fracture, the role of certain physical characteristics, such as body size, on stress-fracture risk is less conclusive. Methods In this study, we investigated the effects of body size and load carriage on lower-extremity joint mechanics, tibial strain, and tibial stress-fracture risk in women. Using individualized musculoskeletal-finite-element-models of 21 women of short, medium, and tall statures (n = 7 in each group), we computed the joint mechanics and tibial strains while running on a treadmill at 3.0 m/s without and with a load of 11.3 or 22.7 kg. We also estimated the stress-fracture risk using a probabilistic model of bone damage, repair, and adaptation. Results Under all load conditions, the peak plantarflexion moment for tall women was higher than those in short women (p < 0.05). However, regardless of the load condition, we did not observe differences in the strains and the stress-fracture risk between the stature groups. When compared to the no-load condition, a 22.7-kg load increased the peak hip extension and flexion moments for all stature groups (p < 0.05). However, when compared to the no-load condition, the 22.7-kg load increased the strains and the stress-fracture risk in short and medium women (p < 0.05), but not in tall women. Conclusion These results show that women of different statures adjust their gait mechanisms differently when running with external load. This study can educate the development of new strategies to help reduce the risk of musculoskeletal injuries in women while running with external load.
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    Musculoskeletal loading during graded running
    (2022-09) Baggaley, Michael; Edwards, W. Brent; Millet, Guillaume; Herzog, Walter; Ferber, Reed
    Running is the most popular recreational activity in Canada, and it is associated with a myriad of physical and mental health benefits. However, running is also associated with the development of musculoskeletal injuries, which lead to lower physical activity levels and interfere with reaping the health benefits of running. Chronic running injuries are thought to result from a fatigue-failure phenomenon, where injuries develop as damage accumulates at the tissue-level over the course of many bouts of running. Damage accumulation is governed by the mechanical loading environment experienced by musculoskeletal tissues; therefore, developing running and rehabilitation programs that can reduce the risk of running injury requires knowledge of the mechanical loading environment. The stress-strain response of a tissue during running is difficult to measure in vivo; however, computational approaches have been developed to infer tissue-level loading. In vivo tissue-level loading has been well characterized during level ground running, but running outdoors often involves traversing graded terrain, which is characterized by a different gait pattern. To develop a comprehensive understanding of musculoskeletal loading during running, it is necessary to capture the mechanical loading environment of the musculoskeletal system during graded and level running. The objective of this thesis was to characterize musculoskeletal loading during running as a function of running grade. To this end, four studies were performed analyzing how individuals adapt to graded terrain as a function of running grade, speed, and step length. It was observed that graded running alters musculoskeletal tissue loading; although the pattern is dependent on many parameters such as the tissue of interest, and the speed, grade, and step length of running. For soft-tissue injuries, it is likely that downhill running may be deleterious and the effect is concomitant with the grade of running. In contrast, the risk of developing a stress fracture may not be altered by running grade, as strains were relatively constant across all grades of running. The findings of this thesis demonstrate the difficulty in capturing in vivo loading and highlight the importance of using tissue geometry to truly capture the effect of different running conditions.
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    A statistical shape model of the tibia-fibula complex: sexual dimorphism and effects of age on reconstruction accuracy from anatomical landmarks
    (2021-11-03) Bruce, Olivia L; Baggaley, Michael; Welte, Lauren; Rainbow, Michael J; Edwards, W Brent
    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.
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    Tibial-fibular geometry and density variations associated with elevated bone strain and sex disparities in young active adults
    (Elsevier, 2022-05-20) Bruce, Olivia L; Baggaley, Michael; Khassetarash, Arash; Haider, Ifaz T; Edwards, W Brent
    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.
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    Water treadmill exercise reduces equine limb segmental accelerations and increases shock attenuation
    (2019-09-13) Greco-Otto, Persephone; Baggaley, Michael; Edwards, W. B; Léguillette, Renaud
    Abstract Background Equine water treadmills (WTs) are growing in popularity because they are believed to allow for high resistance, low impact exercise. However, little is known about the effect of water height on limb loading. The aim of this study was to evaluate the effect of water height and speed on segmental acceleration and impact attenuation during WT exercise in horses. Three uniaxial accelerometers (sampling rate: 2500 Hz) were secured on the left forelimb (hoof, mid-cannon, mid-radius). Horses walked at two speeds (S1: 0.83 m/s, S2: 1.39 m/s) and three water heights (mid-cannon, carpus, stifle), with a dry WT control. Peak acceleration of each segment was averaged over five strides, attenuation was calculated, and stride frequency was estimated by the time between successive hoof contacts. Linear mixed effects models were used to examine the effects of water height, speed, and accelerometer location on peak acceleration, attenuation and stride frequency (p < 0.05). Results Peak acceleration at all locations was lower with water of any height compared to the dry control (p < 0.0001). Acceleration was reduced with water at the height of the stifle compared to mid-cannon water height (p = 0.02). Water at the height of the stifle attenuated more impact than water at the height of the cannon (p = 0.0001). Conclusions Water immersion during treadmill exercise reduced segmental accelerations and increased attenuation in horses. WT exercise may be beneficial in the rehabilitation of lower limb injuries in horses.