Theses and Dissertations at Montana State University (MSU)
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Item The influence of external load during hiking on markers of joint stress and movement efficacy(Montana State University - Bozeman, College of Education, Health & Human Development, 2022) Rowland, Isaac Franco; Chairperson, Graduate Committee: Mary P. Miles; Mary Miles, David Graham, Ron June, Brian Bothner and Hunter Fausset were co-authors of the article, 'The influence of external load during hiking on markers of joint stress and movement efficacy' which is contained within this thesis.PURPOSE: Complications to lower extremity joints, including injury and inflammation, are prevalent issues that arise during prolonged external load-bearing exercise. Metabolomic blood analysis can provide insight into the metabolic processes that occurs during this type of exercise. METHODS: Eight healthy, active men and women participated in a series of blood sample collections and motion capture recording before and after completing a 7.2-mile hiking protocol under two separate conditions. Blood was collected prior to hiking, 15-20 minutes after hiking, 8-hours after, 24-hours after, and 48 hours after. Movement coordination and efficacy was measured with a motion capture system while performing the y-balance test and an obstacle clearance task. Hiking conditions were randomized as backpacking with 20% of body mass external load or daypacking with minimal external load for each participant and separated by two weeks. Serum was analyzed to detect differences in metabolite upregulation between conditions. Biomechanical data were analyzed for inter- and intra-differential values relevant to fatigue between conditions. RESULTS: Analysis found clear differences between conditional metabolite upregulation at all post-hike timepoints. The upregulation of cortisol was significant in backpacking conditions at the post-hike timepoint. Glycerophospholipids were significantly upregulated in backpacking at 8-hours post-hike All significant metabolite upregulation switched to daypacking conditions at 24-hours post-hike. Significant metabolite upregulation varied between conditions at 48-hours post-hike. The only findings of significance in movement coordination and efficacy were between the y-balance lateral leg movement. CONCLUSIONS: The presence of cortisol is consistent with the physiological and mental stress of external loadcarriage and alludes to exposure that can lead to decreased bone mineral content. Glycerophospholipid metabolism pathways play an important role in joint degradation, which could explain their upregulation in backpacking conditions. Ceramide, omega-3s, and fatty acid/triglyceride cycling are functions of cell proliferation and turnover which may be upregulated with more efficiency in daypacking conditions. Upregulation of anserine at 48-hours post-hike in daypacking supports the idea of more efficient exercise recovery occurring in this condition. While significant differences were not clear in motor control measures, the findings show potential reliability for future study designs.Item Habituation during repeated exposure to balance recovery from a forward loss of balance in younger adults(Montana State University - Bozeman, College of Education, Health & Human Development, 2021) Whitten, Justin Mark Moeller; Chairperson, Graduate Committee: David Graham; Dawn S. Tarabochia, John G. Siefert and David F. Graham were co-authors of the article, 'Changes in margin of stability during repeated exposure to forward loss of balance in young adults' submitted to the journal 'Journal of biomechanics' which is contained within this thesis.; Dawn S. Tarabochia, John G. Siefert and David F. Graham were co-authors of the article, 'Changes in muscular effort during repeated exposure to forward loss of balance in young adults' submitted to the journal 'Journal of biomechanics' which is contained within this thesis.The purpose of this study was to begin to develop within session volume parameters for perturbation-based balance training by determining the minimum number of exposures needed for participants to habituate to balance recovery from a substantial perturbation. Two young adult participants were exposed to 15 substantial perturbations induced via release from a static forward lean. All participants were instructed to attempt to recover balance by taking a single rapid step. A scalable anatomical model consisting of 36 degrees-of-freedom and 94 muscle actuators was used to compute kinematics and joint moments from motion capture and force plate data. Margin of stability was calculated at heel strike and maximum knee joint flexion to quantify balance recovery performance. Balance recovery trials were divided in to three blocks (early, middle, and late) with 5 trials in each block and static optimization was used to compute estimates of the mean and peak force generated by key muscle groups during recovery for each block. Participant margin of stability declined rapidly during early balance recovery trials and plateaued between trials 5-8. Hip abductor forces remained relatively consistent across trials while the force produced by the Vastus Femoris group decreased during the mid and late trial blocks. Mean force produced by the Soleus during balance recovery decreased across trial blocks. In contrast, the peak force and impulse generated by the Soleus increased across trial blocks. We interpret these data to reflect an adaptation in balance recovery coordination strategy, which appears to occur sometime between the early and middle trial blocks and stems from young participants desire to minimize the effort associated with successful recovery of balance. These results further suggest participants became habituated to balance recovery after exposure to 5-8 substantial perturbations.Item Patellofemoral joint loading in females during back squats of varying depth, weight load, and stance width(Montana State University - Bozeman, College of Education, Health & Human Development, 2019) Zavala, Linnea Joy; Chairperson, Graduate Committee: James P. Becker; Victoria Flores, Joshua Cotter and James Becker were co-authors of the article, 'Patellofemoral joint loading in females when using different depths and loads in the back squat' submitted to the journal 'Journal of applied biomechanics' which is contained within this thesis.; James Becker was a co-author of the article, 'Patellofemoral joint loading in females during back squats with varying stance widths' submitted to the journal 'Journal of orthopedic sports physical therapy' which is contained within this thesis.As a repetitive and loaded exercise, the back squat can lead to tissue injury. One concern is patellofemoral pain syndrome, a common knee diagnoses over twice as prevalent in females as in males. Patellofemoral joint stress is cited as a cause of the syndrome. To manage the syndrome, quadriceps strength is important. Although the back squat is a good exercise for quadricep strength, modifications to squat technique may be necessary to decrease patellofemoral joint stress. Two studies on female recreational athletes are addressed here: 1) how patellofemoral joint loading changes with squat depth and load and 2) how it changes with squat load and stance width. Depth-specific 1-repetition maximums were measured, and weight loads were based on percentages of the maximum. Peak knee extensor moments, patellofemoral joint reaction forces, and patellofemoral joint stresses were calculated using inverse dynamics and previously reported equations. First, participants squatted to 90°, ~°110, and ~135° of knee flexion with loads of 0%, 50%, and 85% of 1RM. A depth-by-load interaction was found such that within each depth, moments increased as load increased, while decreasing with increased depth. Patellofemoral joint reaction force had main effects of load and depth such that as load increased or depth decreased, reaction force increased. Another depth-by-load interaction was found such that within each depth, as load increased the stress increased, while increasing with increased depth. From these results, squats to full depth or loaded squats to less than 90° of knee flexion are recommended to minimize patellofemoral joint stress. Second, when squatting to ~110° with loads of 35% and 85% and stance widths of 90%, 100%, 110%, and 120% of natural stance, there was a main effect of load for knee extensor moment, patellofemoral joint reaction force, and patellofemoral joint stress. Although altering stance width does not appear to change joint loading, some research suggests that there may be a relationship between foot turnout and joint loading. Continuing relatively simple studies, like these, reveal trends which more individualized approaches can later use, accounting for individuals' anatomy to fully understand patellofemoral joint loading during the back squat.Item Joint moment estimation from electromyography of patients with osteoarthritis(Montana State University - Bozeman, College of Education, Health & Human Development, 2007) O'Keefe, Kathryn Bernadine; Chairperson, Graduate Committee: Michael E. Hahn.Biomechanical gait analysis may be used to determine treatment options, evaluate the success of rehabilitation programs or post-surgery recuperation, and provide insight for surgical planning, including functional outcomes for patients. However, gait analysis requires expensive equipment - a limiting factor for many clinical settings. One alternative that has been examined is the utilization of an artificial neural network (ANN) to model nonlinear relationships of gait. Researchers have shown initial success in ANN predictions of pathological conditions in gait as well as modeling other parameters. The purpose of this study was to evaluate the performance of a previously developed three layer feed-forward ANN model at estimating ankle, knee and hip joint moments for subjects with osteoarthrits (OA) from surface electromyography (EMG) signals. The broader purpose was to further validate the use of the ANN model as an alternative, less expensive method to traditional gait analysis. Eighteen subjects (13 female, 5 male) with physician diagnosed OA participated in this study. Each subject completed a full gait analysis session.Item Flexibility as a determinant of rollerskiing economy in cross-country skiers(Montana State University - Bozeman, College of Education, Health & Human Development, 2007) Camenisch, Karin; Chairperson, Graduate Committee: Daniel P. HeilThe purpose of this study was to examine the correlational relationship between selected measures of flexibility and roller-ski economy (E). Twelve male competitive cross-country skiers (Mean±SD: 21±3 yrs, 183.2±6.5 cm, 76.7±6.8 kg and 60.4±3.4 ml/kg/min VO2max) completed a VO2max test on a motorized treadmill to volitional exhaustion utilizing the Australian XC Ski-Striding protocol. Heart rate (HR) and oxygen consumption (VO2) were recorded with a metabolic cart using standard indirect calorimetry procedures. Immediately following the VO2max test, seven flexibility tests were administered bilaterally twice each by the same administrator in a counterbalanced order. Flexibility measures included rotation of spine, lateral flexion of spine, shoulder rotation, standing and lying horizontal hip abduction, modified sit-and-reach test, and passive leg raise (Flex1-Flex7). During a second lab visit, subjects performed three 10-min trials at preset heart rates (65%, 75%, and 85% of HRmax) using roller-skis on an indoor track oval.