Theses and Dissertations at Montana State University (MSU)
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Item First digital forelimb reconstruction and range of motion assessment of the late Cretaceous dinosaur Troodon formosus(Montana State University - Bozeman, College of Letters & Science, 2023) Serio, Michael Anthony; Chairperson, Graduate Committee: David J. VarricchioTroodon formosus (Troodon) is a theropod dinosaur from the Late Cretaceous of North America primarily known from fragmentary fossil material. Hypothesized to hunt small game, Troodon, like many theropods, may have actively engaged its forelimbs to aid hunting behavior. Furthermore, the complexity of preserved nests associated with Troodon suggest it had sufficient range of motion and dexterity to use its forelimbs to manipulate its eggs. Additionally, Troodon's evolutionary position as one of the closest groups to living birds could indicate important information about the evolution of the avian wing. However, no complete forelimb material has yet been found for Troodon, and as such a complete reconstruction and range of motion (ROM) estimate of its forelimbs has yet to be attempted. This study aims to address these hypotheses and shortcomings by leveraging recent digital modelling technology to create the first forelimb reconstruction and ROM for Troodon. To overcome preservation limitations, surface scans from multiple Troodon fossils housed in the Museum of the Rockies (Bozeman, Montana) were digitally combined to reconstruct most of a forelimb. From this model, digital articulation in the software package Maya was compared with physical articulation ROM methods using 3D printed copies of the forelimb. The maximum angle of allowed motion for each forelimb joint until bone-on-bone contact was assessed. Results show increased flexion over extension in Troodon's joints, consistent with closely related species. However, Troodon also shows higher manual extension than close relatives. The humerus is also shorter and stockier, showing mechanical specialization for strength vs speed, and convergent features with primitive theropod species. These ROM and morphological differences imply a deviation in hunting strategy or forelimb utility and a deviation from avian forelimb morphology. Total manual ROM results cannot confirm whether Troodon was able to grasp its eggs and small prey single-handed, but two-handed apprehension remains feasible. This study utilized digital and physical ROM methods, analyzing for the first-time specimens that would have been previously overlooked. These results shed light on both the foraging and reproductive behavior of Troodon and have implications for understanding the evolution of modern avian reproductive behavior and the dinosaur-bird transition.Item An induced acceleration analysis of the barbell back squat(Montana State University - Bozeman, College of Education, Health & Human Development, 2024) Goodman, William Wesley; Chairperson, Graduate Committee: Dawn Tarabochia; This is a manuscript style paper that includes co-authored chapters.The barbell squat exercise is performed in settings ranging from rehabilitation through to developing muscle size, strength and power. Unfortunately, the lower extremity coordination producing the squat is not clearly understood. This thesis involves three studies evaluating how lower limb joints and muscles coordinate varied squat performance. Study one-three included 13 females who performed squats at three randomized depths (above parallel, parallel, below parallel) using 85% of their 1 repetition maximum at each respective depth. In study one, performance was evaluated by estimating the individual muscle force production and the individual muscle contribution to whole body acceleration using a musculoskeletal model. In study two, performance was evaluated by estimating the individual muscle force production and the individual muscle contribution to the lower body joint accelerations using a musculoskeletal model. In study three, knee joint contact loads were estimated using an advanced musculoskeletal model. Because muscles can accelerate all joints in the body, including a joint that it does not span, musculoskeletal models are necessary to determine muscle function. Varied coordination indicates that depth and load specificity is important and should be taken into consideration when programming based on the status and goals of the individual.Item The effects of angled insoles on short radius flat-track running mechanics(Montana State University - Bozeman, College of Engineering, 2023) Bianchini, Christopher David; Chairperson, Graduate Committee: Corey PewWhile indoor track allows athletes to compete during the winter period of December to February, injury rates during the indoor track and field season are 16% higher than the outdoor season. Increases in injury rates are often attributed to the shorter turn radii experienced by athletes when competing on a 200m indoor track as opposed to the longer turn radii of a 400m outdoor track. A common method of counteracting these asymmetries is to bank the turns of a 200m indoor track. Aligning the athlete's resultant force vector perpendicular to the running surface can alleviate many of the running form abnormalities caused by turn running. However, the high cost of implementing a banked indoor track can be prohibitive to many programs who currently have a flat track facility. To this end, we have developed two experimental insoles designed to alleviate the asymmetries experienced during turn running: a physically angled foam insole and an insole containing an angled stiff mid-plate. Insole function was tested through human participant running trials to identify their effects on indoor flat track running mechanics. 12 NCAA Division 1 track and field athletes (6 male, 6 female, age: 21 + or - 2 years, mass: 61.4 + or - 11.4 kg, height: 1.77 + or - 0.17 m) who specialize in distance and mid-distance running provided informed consent to participate in this Institutional Review Board-approved protocol. Kinematics, muscle activation, and ground interaction variables were monitored during running trials and used to compare the effects of the insoles on running biomechanics. The physically angled insole produced positive results for ankle joint angles and ground interaction variables for turn running. The angled plate insole positively affected right-side ankle joint angle positioning and did not significantly impact straight running mechanics. Both insoles produced higher levels of muscle activation asymmetry, indicating that this may be a required effect of turn running regardless of joint angle positioning and ground interaction. While the angled plate insoles showed almost no impact on straight or turn running mechanics, the wedge insoles functioned effectively to alleviate several asymmetries related to turn running.Item Small scale stimuli and the cricket cercal system(Montana State University - Bozeman, College of Agriculture, 2022) Mulder-Rosi, Jonas L.; Co-chairs, Graduate Committee: Charles M. Gray and R. Steven Stowers; This is a manuscript style paper that includes co-authored chapters.The cricket cercal system has been a model system in neuroscience for over 30 years. Anatomy, physiology, and theory have all come together to produce a picture of a system with a clear purpose: encoding air direction around the animal. However, certain features of the system have suggested that these cells may be sensitive to additional stimulus dimensions. To address this limited stimulus space I designed new experiments to test these neurons' responses to previously untested stimuli. I used a novel extracellular recording mechanism able to record and sort several neurons' responses at the same time. I built and tested several stimulators to provide small-scale puffs to specific parts of the sensory array at specific times. With these, I was able to test this model neural system against a complex stimulus space. I show here that these neurons respond to several additional stimulus dimensions. They are tuned to the timing of stimuli across the array. They show differential responses to even more complex stimuli with varying stimulus directions in different locations across the array. This implies that the previous understanding of the system was likely limited by how it was tested. While these cells accurately encode the direction of large-scale airflow, they also encode other aspects of stimuli, such stimulus timing and small-scale variations in stimulus direction. Thus the "function" of these neurons may be far more complex than previously understood.Item Computationally modeling the aeroelastic physics of flapping-wing flight(Montana State University - Bozeman, College of Engineering, 2023) Schwab, Ryan Keith; Chairperson, Graduate Committee: Mark Jankauski; This is a manuscript style paper that includes co-authored chapters.Flying insects use flapping wings to achieve flight at minuscule sizes. These flapping wings deform elastically under both inertial and aerodynamic loading. While conventional aircraft are often designed to reduce flexibility in their wings, insects harness the benefits of wing flexibility through elastic potential energy storage and enhancement of flapping wing- specific aerodynamic phenomena. Aircraft at insect size scales could have an inexhaustible number of uses ranging from monitoring of congested piping networks in oil refineries, to extraterrestrial land surveyance in thin atmospheres. If these micro air vehicles are to be realized, however, they will need to harness the aerodynamic benefits of flapping wings in order to overcome unfavorable ratios of lift to drag forces and inefficiencies of DC motors at such small sizes. Study of flapping wing aeroelastics is complicated due to the large-amplitude rotations of the wings, unsteady dynamics of the fluid regime, and small size and weight scales of the wings. While some experimental work focuses on techniques like measuring kinematics through motion tracking with high-speed videography, and partial flow field measurements through particle image velocimetry, it is difficult to conduct experiments that paint a full picture of the fluid-structure interaction of these wings. Instead, this research focuses on high-fidelity computational modeling through bilaterally coupled computational fluid dynamics and finite element analysis software to understand the fluid-structure interaction of flapping wings. In this work, a reduced order modeling technique capable of calculating the bulk aeroelastic physics of flapping wings at computational efficiencies suitable for parameter optimization studies was also validated. Finally, the influence of tapered wing thickness on aeroelastics and energetic efficiency was studied. While wing tapering reduced mean thrust, it had a greater reduction on the energetic requirement to produce flapping kinematics and was therefore more energetically efficient.Item Importance of foot and leg structure for beef cattle in forage-based production systems: characterizing foot and leg scores for Montana Angus cattle(Montana State University - Bozeman, College of Agriculture, 2023) Sitz, Taylre Elizebeth; Chairperson, Graduate Committee: Timothy DelCurtoThe objectives of this study were to increase the amount of phenotypic data available for enhancing the foot and claw EPDs of Montana sires and evaluate factors that could impact foot angle and claw set scores. Specifically, this study evaluated the interaction of sex and age on claw set and foot angle scores of front or hind legs. Researchers used the American Angus Association (AAA) Foot Scoring Guidelines to subjectively analyze claw set and foot angle on a series of Montana Angus herds, scoring a total of 4,723 cattle: 1,475 yearling bulls, 992 yearling heifers, 1,044 two- and three-year-old cows, and 1,212 cows that were four years and older. The AAA Foot Scoring Guidelines require breeders to score the combined "worst foot" for both the claw set and foot angle traits on a hard, flat surface. Yearling bulls had a 0.12 and 0.20 greater mean foot angle and claw set score compared to yearling heifers (P < 0.01). The proportion of scores that differed from 5 (ideal foot score) were greater (P < 0.01) for front feet as compared with hind feet, with 61.5 and 74.5% of the scores not equal to 5 being front feet issues for yearling heifers and bulls, respectively. Foot angle scores increased linearly (P < 0.01) with advancing cow age, ranging from 5.15 to 5.80 for heifers versus cows 4 years and older, respectively. Likewise, claw set scores increased quadratically (P < 0.01) as a function of cow age. The location of the "worst foot" also changed quadratically with age (P < 0.01) with the majority of problem feet in 2/3 year old cows and cows 4 years and older being hind feet issues (70.5 and 77.1% respectively). The proportion of foot angle and claw set scores not equal to 5 also increased quadratically with age (P < 0.01) with heifers having the lowest proportion of scores not equal to 5 (15.8 and 31.7%, respectively) compared to 4 yr and older cows (66.0 and 68.0%, respectively). In analysis of progeny of sire lines, the range between the progeny of the sire line with the greatest foot angle score and that of the least was 0.60 for foot angle. Likewise, for claw set, a similar range 0.57 was observed. Sire lines did have an effect on progeny claw set (P < 0.05) and foot angle scores (P < 0.05), as well as variation of progeny foot scores. In summary, progress is being made by utilizing the AAA foot scoring guidelines, as well as foot angle and claw set EPDs. Additional improvements may be possible with continued model refinement and improvements with scoring guidelines specific to age and sex effects.Item Using a beam theory model to quantify metatarsal bone stress during running(Montana State University - Bozeman, College of Education, Health & Human Development, 2023) McKibben, Kaitlyn Marie; Chairperson, Graduate Committee: James N. Becker; This is a manuscript style paper that includes co-authored chapters.Running is a common fitness activity that is associated with a high incidence of overuse injuries, including metatarsal stress fractures. One contributor to stress injury is repetitive loading of the metatarsals without adequate recovery time and experiencing larger volumes and magnitudes of bone loading may increase injury risk. Thus, quantifying metatarsal loads can be beneficial to understanding injury risk. However, it is currently difficult to estimate bone stress in clinical settings and unclear how bone stress changes following a long run. Therefore, the purpose of this thesis was to 1) characterize changes in metatarsal bone stress before and after the completion of a long-distance run, and 2) suggest a clinically feasible method for estimating metatarsal bone stress. Study 1 involved 21 healthy long-distance runners who ran 25% of their average weekly mileage on an instrumented treadmill. Foot kinematics, ground reaction forces, and in-shoe plantar pressures were collected at the beginning and end of the run and a mathematical model was used to estimate bone stresses and bending moments for all five metatarsals. Plantar stress, dorsal stress, and midshaft bending moments in the second and third metatarsals were greater after the completion of the run. This is consequential for injury risk because the second and third metatarsals are the most susceptible to stress fracture development. In study 2, seventeen runners ran barefoot across a force plate overlaid with a plantar pressure mat while foot kinematics were recorded. The same mathematical model of the metatarsals was used to estimate third metatarsal bone stresses and bending moments, and linear regressions determined whether force or pressure beneath the metatarsal predicted bone loads. A model containing head and base pressure differentials and force beneath the metatarsal head was the best predictor of bone loading, indicating that the use of plantar pressure measurements as a surrogate measure of bone stress could be a time and cost-effective method for estimating bone stress in clinical settings. Moving forward, elucidating how metatarsal bone stress changes over the course of a long run and finding more accessible ways to quantify bone stress could help alleviate injury risk.Item Manipulating implement weight during warm up to improve shot put performance(Montana State University - Bozeman, College of Education, Health & Human Development, 2023) Klein, Leah Nicole; Chairperson, Graduate Committee: James N. Becker; This is a manuscript style paper that includes co-authored chapters.The purpose of this study was to investigate the use of overweight and underweight implements impacts on shot putting performance along with technical and physiological changes. Ten collegiate shot putters participated in this study (6 male, 4 female). Each participant completed 3 non consecutive days of data collection. Each day consisted of 3 warm up throws followed by 6 maximal effort regulation weighted throws. Warm up throws consisted of one of three conditions: (1) overweight (2) underweight or (3) regulation. In agreement with prior literature on post-activation potentiation (PAP), those who threw with overweight implements showed significant increases in performance. No changes in critical factor kinematics or ground reaction force measures were affected by warm up weight. Results of this study conclude that using a heavy implement during warmups is a functional way to improve performance, however more research is needed to further uncover the underlying mechanisms.Item Investigating high-risk biomechanics in agricultural work(Montana State University - Bozeman, College of Engineering, 2022) Doud, Devon Michael; Chairperson, Graduate Committee: Scott Monfort; This is a manuscript style paper that includes co-authored chapters.Statement of Purpose: Osteoarthritis, a debilitating disease resulting in cartilage degradation and loss of mobility, is often instigated by injury or excessive loading of unconditioned articular cartilage. Although agricultural laborers are especially at risk of developing osteoarthritis, quantitative characterizations of occupation-specific activities have not previously been established. Deep flexion movements common to these groups (e.g., squatting or kneeling) may cause excessive contact forces on unconditioned cartilage, potentially initiating osteoarthritis development. Additionally, although cognitive loads can significantly alter gait mechanics, the effects of dual-task conditions (e.g., visual Stroop tests while walking) on contact forces have not previously been established. The purpose of this thesis is to better understand potential factors of osteoarthritis development in agricultural laborers by investigating occupational-specific movement patterns and joint loading during common occupational tasks. Methods: The first study evaluated seasonal differences in activity levels for farmers and ranchers by measuring movement intensity via wearable triaxial accelerometers. We hypothesized that ranchers would exhibit consistently high activity levels and that both groups would show an increase in movement intensity in their respective high seasons. The second study sought to establish the effects of cognitive challenges on tibiofemoral contact forces during normal gait and kneel-to-stand transitions in healthy adults. We hypothesized that dual-task conditions would correspond with increased peak tibiofemoral contact forces and that these forces would be positioned farther from the joint center along the mediolateral axis during dual-task conditions. Results: The first study findings largely supported the hypothesis: increased movement intensity during high seasons were recorded for both groups, with farmers exhibiting a larger seasonal fluctuation for moderate intensity activities. The second study did not support the hypothesis: cognitive loading did not significantly affect the magnitude of peak contact forces, and peak contact forces occurred closer to the joint center during dual-task conditions than during single-task conditions. However, post hoc analysis suggested that other portions of the contact force time series during stance phase were affected by cognitive challenges. Conclusions: This thesis provides foundational steps in understanding potential contributing factors of osteoarthritis development in agricultural laborers, directing future investigations towards transitional contact forces in movements simulating livestock handling.Item Practicality and usability of high-density surface electromyography for lower limb prosthesis control(Montana State University - Bozeman, College of Engineering, 2022) Christensen, Fred Wallace; Chairperson, Graduate Committee: Corey PewSurface electromyography (sEMG) presents a pathway for prosthesis control but is prone to excess noise and signal corruption due to displacement. High Density Surface Electromyography (HDsEMG), which covers the same area as Traditional sEMG with multiple electrode channels as opposed to one channel, presents a way to overcome these challenges. Seven healthy participants were recruited and performed several activities of daily living with both Traditional sEMG and HDsEMG sensors on their Rectus Femoris, Biceps Femoris, Vastus Lateralis, and Semitendinosus muscles. These sensors were placed in both optimal locations over the muscle belly and in a location 1 cm distally from that optimal placement to simulate sensor displacement with use. From the data collected, four signals were created: a Traditional sEMG signal, the single HDsEMG signal with the highest signal-to-noise ratio (SNR) (Best Signal), a time mean of all HDsEMG signals (Composite Signal), and a time mean of all HDsEMG signals with SNR values greater than 2 dB (Threshold Signal). All signals' values for SNR, root-mean-squared means (RMS), DP ratio, and Omega ratio were compared in both optimal and displaced conditions. Phase lag and power domain similarity were used to assess response to displacement. Threshold mean and straight mean signals were identical in most values. The best signal displayed highest SNR, with the composite signal displaying second highest, and sEMG displaying lowest. These differences were more pronounced in extensor muscles in activities that involved large amounts of knee movements. sEMG signals displayed higher relative RMS values, as well as higher DP values. sEMG displayed statistically higher, but numerically similar Omega values. sEMG displayed a greater agreement between optimal and displaced signals in the frequency domain. Similarity was more dependent on activity type than signal type. Phase lag was determined to not be relevant. HDsEMG was proved to have potential for improved prosthesis control.
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