Theses and Dissertations at Montana State University (MSU)
Permanent URI for this collectionhttps://scholarworks.montana.edu/handle/1/733
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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 The influence of splitboard bindings and touring-specific boots on muscle activity, stride length, and joint kinematics during splitboard touring(Montana State University - Bozeman, College of Education, Health & Human Development, 2017) Valentin, Celine McShea; Chairperson, Graduate Committee: John G. SeifertSplitboarding is a form of alpine recreation that involves using a snowboard that splits into two skis to tour in backcountry terrain. At the summit, the skis are attached together and used as a normal snowboard to ride downhill. As splitboarding has grown in popularity, manufacturers have developed splitboard-specific equipment, such as bindings and boots. This crossover study investigated the effects of highback lean settings on Spark R&D splitboard bindings and two Burton Snowboards boot models while touring uphill. Subjects toured on a treadmill at a 10% incline in four test conditions: the Driver X boot with positive lean, the Driver X boot with negative lean, the Tourist boot with positive lean, and the Tourist boot with negative lean. Lower limb muscle activity was recorded as average root-mean-square (RMS) for gluteus medius (GM), biceps femoris (BF), rectus femoris (RF), medial gastrocnemius (MG), and tibialis anterior (TA). Kinematics variables of stride length, and ankle and knee range of motion (ROM) were also measured. The effects of the boots and bindings were determined using a two-way repeated measures analysis of variance (alpha < 0.05). The main effect of binding on average RMS was not significant for all muscles except MG (F = 8.821, p = 0.018, f = 1.05), with the negative lean having higher average RMS than the positive lean. The main effect of boot on stride length was significant (F = 15.791, p = 0.003, f = 1.33), with the Tourist resulting in a 3.56 cm longer stride length that the Driver X. The main effect of binding on stride length was also significant (F = 9.875, p = 0.012, f = 1.05), with negative lean resulting in a 2.21 cm longer stride length than the positive lean. The main effect of boot model on ankle ROM was significant (F = 36.325, p = 0.000, f = 2.00), with the Tourist having a larger ROM than the Driver X. There were no significant effects or interactions for knee ROM. The results of this study demonstrate that boot model and binding settings can affect biomechanical and physiological variables while splitboard touring.Item A kinematic analysis of a telemark ski turn(Montana State University - Bozeman, College of Education, Health & Human Development, 1998) Trafton, Thomas AllenItem The effect of lower limb loading on economy and kinematics of skate roller skiing(Montana State University - Bozeman, College of Education, Health & Human Development, 2014) Reinking, Tyler Johnson; Chairperson, Graduate Committee: Daniel P. Heil; Daniel P. Heil was a co-author of the article, 'The effect of lower limb loading on economy and kinematics of skate roller skiing' submitted to the journal 'European journal of applied physiology' which is contained within this thesis.It has been proposed that skate skiing economy and racing performance have improved as a result of lighter equipment. Despite the many studies that have found running and walking economy to improve with lighter shoes, there are no published studies that show any relationship between the mass of skate skiing equipment and markers of skate skiing performance. To investigate the effects of skate skiing equipment mass on markers of performance, this study added mass to the lower limbs of skate roller skiers and measured changes in economy and gross movement kinematics. Twelve male (Mean±SD; Age (yrs): 21.4±3.9) and eight female (Mean±SD; Age (yrs): 19.9±2.2) competitive cross-country skiers completed two laboratory visits to roller ski on an oversized treadmill. In the first visit, subjects completed a graded exercise test to determine their lactate threshold. In the second visit, subjects completed 5 minutes of roller skiing at a low work rate (2 m/s for women and 3 m/s for men both at 2°) and a high work rate (2 m/s for women and 3 m/s for men both at 3.15°) for each of the four limb loading conditions (0 g, 200 g, 400 g, and 600 g). Oxygen consumption (VO2), heart rate (HR), and cycle rate were measured during the last 2 minutes of each stage and used for analysis. There were no significant differences in HR, VO2, or cycle rate between any of the limb loading conditions at either work rate. However, cycle rate neared significance (P = 0.06), with increases in cycle rate observed during greater limb loading. Interestingly, VO2 and HR significantly increased throughout testing, independent of limb loading condition. The most notable increases were observed in HR values, and increases began within the very first testing stage. Thus, it is likely that the subjects experienced cardiovascular drift due to mild hyperthermia. The effects of hyperthermia might have masked the true effects of lower limb loading. Therefore, future studies still need to investigate the effects of lower limb loading on skate skiing economy and kinematicsItem Upper extremity kinematics and joint coordination of fly-casting(Montana State University - Bozeman, College of Education, Health & Human Development, 2006) Allen, Joshua Ryan; Chairperson, Graduate Committee: Michael E. Hahn.Little research exists that focuses on the motions and coordination common to fly-casting. It was hypothesized that kinematic parameters of casting (peak and total range of motion, timing of peak joint angular velocity, and magnitude of peak joint angular velocity) would increase in order to cast lines of greater length. Also, it was hypothesized that when greater length of line is cast, the time between peak angular velocities would decrease. The purpose of this study was to determine the kinematic and joint coordination changes necessary to cast lines of different length. Eighteen male subjects participated in the study. Experience ranged from intermediate to expert, with a number of the subjects being professional fly-fishing guides. Twenty three reflective markers were tracked by a 6-camera Vicon® digital capture system. Shoulder motion was calculated with respect to the trunk. The elbow was modeled as a uni-axial pin joint and the wrist as a bi-axial pin joint.