Gauri Desai , Ph.D.

Low energy availability (LEA) impairs musculoskeletal health, with emerging evidence of impaired neuromusculoskeletal adaptations to training. We aimed to synthesise the existing evidence examining neuromusculoskeletal responses to training stimuli among individuals with LEA. 10 studies identified that those with LEA had impaired lean mass/FFM responses (−1% to −5%), and 10 found no substantial changes over time (<1%). Six studies identified functional/sport-specific impairments over time among those with LEA (−4% to −10%). All remaining primary adaptations (strength, limb circumference, cellular-level and subjective measures) were impaired with LEA.

This study examined the associations of age and running experience with shock attenuation during running, as age and experience may influence passive (body composition) and active (gait) shock attenuation mechanisms. We found that age and running experience independently influence shock attenuation, suggesting different shock attenuation responses between runner sub-populations.

We compared external mechanical work between socket-suspended and bone-anchored transfemoral prosthesis users during walking and identified if these differences are accompanied by those in their metabolic costs of walking. We hypothesized that socket users would perform more net and negative external mechanical work in their prosthetic limb over the gait cycle and exhibit a higher metabolic cost of walking than bone-anchored prosthesis users. Net mechanical work done by the prosthetic limb was not significantly different between groups, but socket users showed greater external negative mechanical work accompanied by a 10.13 % greater metabolic cost of walking than bone-anchored prosthesis users.

The objective of this systematic review was to examine the evidence concerning the influence of experience on running biomechanics and summarize the criteria used to classify running experience. We conclude that heterogeneous study designs must begin with standard experience classification criteria for the effect of experience on running biomechanics to be identified. We propose an updated taxonomy to classify runners into groups considering three facets: exposure, performance, and intention.

We investigate differences in cumulative biomechanical risk factors associated with KOA between male and female individuals. Differences in PUD KAM and MJCF were examined using one-tailed unpaired Student’s t-tests. Differences in speed were examined using two-tailed unpaired Student’s t-tests. The higher prevalence of KOA experienced by females may be partially attributed to greater PUD biomechanical risk factors, as females walked with greater PUD KAM compared to males. Planned future research will analyze these risk factors among both sexes in larger sample sizes. Interactions of these gender differences in mechanical loads with joint geometry, cartilage tissue properties, and sex hormones may also affect the osteoarthritis risk.

This dissertation aimed to examine gait and body composition mechanisms that attenuate vibrations during running, and the influence of age and running experience on shock attenuation. These results indicate that middle-aged and novice runners may attenuate less shock due to their typically greater fat mass and less compliant gait than younger and more experienced runners.

The purpose of this study is to determine the relationship between ankle, knee, and hip joint kinetics and weekly moderate to vigorous physical activity (MVPA) minutes among active adults. A 3D overground running gait analysis was performed on 44 active adults (18-65 years). Joint work ratios (ankle:hip, ankle:knee, knee:hip) and %contribution of each joint to total lower limb positive and negative work were calculated (outcomes). Subjects wore a wrist-worn PA tracker for 2 weeks. Our results indicate amplified biomechanical plasticity from the ankle to knee with increased weekly MVPA. Consistent with previous research (Malero et al., JAB, 2020), this unexpected trend may be due to increased muscle capacity at the knee but not ankle with greater PA exposure. MVPA composition in addition to weekly minutes may influence plasticity.

Examining the effects of prolonged running on gait mechanics is needed to understand the multifactorial nature of running injury. However, the window of opportunity to capture the effects of a sub-exhaustive prolonged run on gait is unknown. Five runners completed overground motion capture before and after a ‘typical’ sub-exhaustive treadmill run (3.9 ± 1.6 km; RPE 15.8 ± 1.1). Intra-class correlation coefficients were used to determine time to stabilization. Kinematic changes following the treadmill run persisted for 342 ± 98 sec (~4 min). Our findings indicate that alterations in gait resulting from a simulated ‘typical’ run on a treadmill may dissipate within four minutes. Time to stabilization may differ between variables of interest and between less and more experienced runners. We recommend that collection of overground data be complete within 4-minutes following a prolonged run in order to depict the gait performed in a sub-exhaustive state.