Mechanical & Industrial Engineering
Permanent URI for this communityhttps://scholarworks.montana.edu/handle/1/33
The mission of the Mechanical & Industrial Engineering Department is to serve the State of Montana, the region, and the nation by providing outstanding leadership and contributions in knowledge discovery, student learning, innovation and entrepreneurship, and service to community and profession.
Browse
6 results
Search Results
Item Development and reliability of a visual-cognitive medial side hop for return to sport testing(Elsevier BV, 2022-09) Farraye, Byrnadeen T.; Chaput, Meredith; Simon, Janet E.; Kim, HoWon; Grooms, Dustin R.; Monfort, Scott M.Objectives. To develop and evaluate the reliability of a new visual-cognitive medial side hop (VCMH) test that challenges physical and cognitive performance to potentially improve return to sport testing. Design. Test-retest experimental design. Setting. Laboratory. Participants. Twenty-two healthy college students participated (11 females; 23.5 ± 3.64 years; 172.9 ± 11.58 cm; 74.1 ± 17.25 kg; Tegner Score 5.6 ± 1.1). Main outcome measures. Subjects performed a medial side hop for distance with and without a visual-cognitive task (VCMH). Maximum hop distance and cognitive errors were measured. Results. There was strong reliability for the traditional medial side hop (ICC3,1 = 0.88[0.72, 0.95]; SEM = 7.16 cm) and VCMH distances (ICC3,1 = 0.86[0.66, 0.94]; SEM = 6.82 cm). Maximum hop distance was significantly lower during the VCMH (86.9 ± 18.2 cm) compared to the traditional medial side hop (96.3 ± 20.7 cm; p < 0.05; d = 0.74), with a performance deficit of 9.69%. Conclusion. The VCMH has high test-retest reliability and resulted in a significant dual-task cost with a reduction in physical performance when compared to the traditional medial side hop.Item Effects of cognitive- and motor-dual tasks on postural control regularity following anterior cruciate ligament reconstruction(Elsevier BV, 2022-09) Monfort, Scott M.; Simon, Janet E.; Miko, Sarah C.; Grooms, Dustin R.Background. High injury rates following anterior cruciate ligament reconstruction (ACLR) motivate the need to better understand lingering movement deficiencies following return to sport. Athletic competition involves various types of sensory, motor, and cognitive challenges; however, postural control deficiencies during this spectrum of conditions are not well understood following ACLR. Research question. To what extent is postural control altered following ACLR in the presence of sensory, motor, and cognitive challenges, and does postural control correlate with patient-reported symptoms? Methods. Fourteen individuals following ACLR (4 m/10 f, 21.2 ± 2.4 yr, 76.9 ± 19.1 kg, 1.70 ± 0.14 m) and fourteen matched healthy controls (4 m/10 f, 21.2 ± 1.4 yr, 75.4 ± 15.3 kg, 1.70 ± 0.15 m) participated in the study. Participants completed single-leg balance, ACLR limb or matched side for controls, under four conditions: 1) eyes open, 2) eyes closed, 3) visual-cognitive dual task (i.e., reverse digit span), and 4) motor dual task (i.e., catching a ball). Sample entropy (SEn) was calculated for each balance condition to characterize regularity of center of pressure control. Participants also completed patient-reported outcomes to characterize self-reported knee function, symptoms, and fear. A mixed effects model tested for differences in SEn between balance conditions, and Spearman correlations tested for relationships between SEn and patient-reported outcomes. Results. A significant Group-by-Condition interaction was detected (P = 0.043). While the motor dual task and eyes closed balance conditions were associated with the lowest SEn for both groups, only the visual-cognitive dual task condition demonstrated a significant difference between groups, with the ACLR group having lower SEn [95% confidence interval for ΔSEn: (0.03, 0.35)]. Lower KOOS-Sport scores were associated with decreased SEn for the ACLR group (ρ = 0.81, P < 0.001). Significance. These findings are consistent with ACLR individuals using a less automatic approach to postural control compared to controls, particularly when presented with a visual-cognitive challenge. Altered neuromuscular control persists well after ACLR surgery and can be related to patient-reported outcomes.Item Influence of serial subtraction tasks on transient characteristics of postural control(Elsevier BV, 2022-06) Reed, Cody A.; DuBois, Camryn K.; Hutchison, Keith A.; Huppert, Theodore J.; Monfort, Scott M.We sought to better understand the influence of cognitive perturbations on transient aspects of postural control. Twenty healthy, younger adults had their postural control assessed during eyes open quiet stance. Participants completed three different conditions that either had no cognitive perturbation present, an easy cognitive perturbation (i.e., serial subtraction by ones), or a more difficult cognitive perturbation (i.e., serial subtraction by sevens). All trials finished with 60 s of undisturbed eyes open quiet stance, which was the focus of the balance assessment. 95% confidence ellipse area (EA) was calculated for 5-s epochs throughout the trial. The difference in EA from the first epoch after participants started (onset) or stopped (offset) the cognitive task to the last epoch of the trial (i.e., 55–60 s after perturbation) was used to characterize transient postural control behavior. Functional near-infrared spectroscopy was also used to quantify changes in prefrontal cortex activation during the counting tasks to support interpretation of the transient balance findings. There was a significant effect of condition for transient balance characteristics following a cognitive perturbation (P < 0.001), with greater transient increases in postural sway for both difficult (Cohen's d = 0.40, P < 0.001) and easier (Cohen's d = 0.29, P = 0.013) cognitive perturbations relative to no cognitive perturbation. The onset of cognitive tasks was also associated with greater transient increases in postural sway than the offset of the cognitive tasks (Cohen's d = 0.24, P = 0.019). The functional near-infrared spectroscopy data indicated that a significant decrease in deoxygenated hemoglobin was observed for left Brodmann area 46 for both the subtraction by ones (T = −3.97; Benjamini-Hochberg significance value (q) = 0.008) and subtraction by sevens (T = −3.11; q = 0.036) conditions relative to the baseline condition. The subtraction by sevens condition was also associated with a relative increase in deoxygenated hemoglobin for the right Brodmann area 9 (T = 3.36; q = 0.026) compared to the subtraction by ones condition. In conclusion, serial subtraction can elicit transient increases in postural sway, with more difficult tasks and the onset of the cognitive-motor challenge exhibiting magnified effects. Additionally, even the cessation of a cognitive task (i.e., serial subtraction) can be associated with lingering perturbing effects on balance control.Item Quantifying National Biomechanics Day’s Impact on Student Perceptions toward Biomechanics: A Multisite Pilot Study(Elsevier BV, 2021-12) Monfort, Scott M.; Bigelow, Kimberly E.; Vallabhajosula, Srikant; Evertz, Loribeth Q.; Becker, James N.; Wittstein, Matthew W.; Gannon, Paul; DeVita, PaulNational Biomechanics Day (NBD) is an international celebration of biomechanics that seeks to increase the awareness and appreciation of biomechanics among the high school community. Initial research supports the positive effects of NBD on students’ attitudes toward the field of biomechanics; however, quantitative evidence remains scarce. The purpose of this study was to quantify changes in high school students’ perceptions toward biomechanics after participating in NBD events to better understand the impact of NBD. Data were collected at two locations during the 2019 NBD season. Surveys were collected before and after NBD events for 112 high school students from Montana and North Carolina. Paired pre- versus post-NBD surveys for the aggregate sample population suggest that students perceived biomechanics as more appealing (p = 0.050), exciting (p = 0.007), and important (p = 0.018) following the NBD events. Students did not report a change in whether they could see themselves in a biomechanics-related career (p = 0.49). These findings further support the ability for NBD events to positively impact students’ perceptions toward biomechanics, although opportunities persist to increase student career interest in biomechanics. This paper presents and discusses the study’s results, interpretations, limitations, and implications for future research on biomechanics outreach activities.Item A new perspective on transient characteristics of quiet stance postural control(2020-08) Reed, Cody A.; Chaudhari, Ajit M. W.; Worthen-Chaudhari, Lise C.; Bigelow, Kimberly E.; Monfort, Scott M.Postural control provides insight into health concerns such as fall risk but remains relatively untapped as a vital sign of health. One understudied aspect of postural control involves transient responses within center of pressure (CoP) data to events such as vision occlusion. Such responses are masked by common whole-trial analyses. We hypothesized that the transient behavior of postural control would yield unique and clinically-relevant information for quiet stance compared to traditionally calculated whole-trial CoP estimates. Three experiments were conducted to test different aspects of this central hypothesis. To test whether transient, epoch-based characteristics of CoP estimates provide different information than traditional whole-trial estimates, we investigated correlations between these estimates for a population of young adults performing three 60-second trials of quiet stance with eyes closed. Next, to test if transient behavior is a result of sensory reweighting after eye closure, we compared transient characteristics between eyes closed and eyes open conditions. Finally, to test if there was an effect of age on transient behavior, we compared transient characteristics during eyes closed stance between populations of young and older adults. Negligible correlations were found between transient characteristics and whole-trial estimates (p>0.08), demonstrating limited overlap in information between them. Additionally, transient behavior was exaggerated during eyes closed stance relative to eyes open (p<0.044). Lastly, we found that transient characteristics were able to distinguish between younger and older adults, supporting their clinical relevance (p<0.029). An epoch-based approach captured unique and potentially clinically-relevant postural control information compared to whole-trial estimates. While longer trials may improve the reliability of whole-trial estimates, including a complementary assessment of the initial transient characteristics may provide a more comprehensive characterization of postural control.Item Impaired Postural Control and Altered Sensory Organization During Quiet Stance Following Neurotoxic Chemotherapy: A Preliminary Study(2019-02) Monfort, Scott M.; Pan, Xueliang; Loprinzi, Charles L.; Lustberg, Maryam B.; Chaudhari, Ajit M. W.Individuals diagnosed with chemotherapy-induced peripheral neuropathy (CIPN) demonstrate impaired balance and carry an increased risk of falling. However, prior investigations of postural instability have only compared these individuals against healthy controls, limiting the understanding of impairments associated with CIPN. Therefore, the purpose of this study was to better isolate postural control impairments that are associated with CIPN. Twenty cancer survivors previously diagnosed with breast or colorectal cancer participated. Participants were separated into 3 groups: no prior chemotherapy exposure (CON, n = 6), and recent treatment with taxane- or oxaliplatin-based chemotherapy with no/mild symptoms of CIPN (-CIPN, n = 8) or moderate/severe symptoms of CIPN (+CIPN, n = 6). Postural control was assessed by measuring center of pressure during standing balance conditions that systematically interfered with somatosensory, visual, and/or vestibular information. The presence of CIPN sensory symptoms was associated with impaired postural control, particularly during eyes-closed balance conditions (P < .05). Additionally, medial-lateral postural instability was more pronounced in the +CIPN group compared with the -CIPN group and CON participants (P < .05). Greater postural instability during eyes-closed balance in individuals with CIPN is consistent with impaired peripheral sensation. Balance impairments in cancer survivors with CIPN demonstrate the unique challenges in this population and motivate the need for targeted efforts to mitigate postural control deficits that have previously been associated with fall risk.