A Finite Element Model of the Superior Glenoid Labrum

Despite numerous studies on the function and pathologies of the shoulder joint’s superior glenoid labrum, controversy still exists concerning the mechanism of injury to the superior labral in the anterior to posterior direction (SLAP), and thus the optimal treatment. In this dissertation, the working hypothesis was that it is possible to use finite element models to explore the factors underlying the initiation and propagation of a SLAP lesion. First, the finite element model was validated for studying the tear mechanism in the superior labrum. An area of high strain correlated well with the location of SLAP tears observed clinically. The validated model was then used to evaluate the effect of both superior translation of the humeral head and tension on the long head of the biceps tendon on the strain in the intact labrum. The humeral head motion was found to have relatively greater effect than the biceps tension on the initiation of the SLAP tear. Repetitive micro-trauma or tissue fatigue rather than a single loading event is most likely to cause a mid-substance failure of the labrum. This work also tested the effect of the biceps tension on the propagation of SLAP tears using the finite element model. With loading of the biceps, the model predicted high strains at the edges of the tear suggesting a high risk for progression of the tear. For larger tears, the effect of the biceps was more pronounced. Based on this work, tear size is suggested as one criterion for determining the optimal treatment of the SLAP lesion. During development of the finite element model, simplifying assumptions were necessary. With careful consideration of the effect of these assumptions and simplifications on the results, the current work suggests a plausible mechanism of injury for SLAP lesions. This work is to identify the role of humeral head translation and biceps loading in the initiation and propagation of SLAP tears by examination of the predicted strain.PHDKinesiology and Biomedical EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/107176/1/ejhwang_1.pd

Effects of biceps tension and superior humeral head translation on the glenoid labrum

We sought to understand the effects of superior humeral head translation and load of the long head of biceps on the pathomechanics of the superior glenoid labrum by predicting labral strain. Using micro‐CT cadaver images, a finite element model of the glenohumeral joint was generated, consisting of humerus, glenoid bone, cartilages, labrum, and biceps tendon. A glenohumeral compression of 50 N and biceps tensions of 0, 22, 55, and 88 N were applied. The humeral head was superiorly translated from 0 to 5 mm in 1‐mm increments. The highest labral strain occurred at the interface with the glenoid cartilage and bone beneath the origin of the biceps tendon. The maximum strain was lower than the reported failure strain. The humeral head motion had relatively greater effect than biceps tension on the increasing labral strain. This supports the mechanistic hypothesis that superior labral lesions result mainly from superior migration of the humeral head, but also from biceps tension. © 2014 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 32:1424–1429, 2014.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/108670/1/jor22688.pd

Effects of biceps tension on the torn superior glenoid labrum

The purpose of this study was to evaluate the role of the tension on the long head of the biceps tendon in the propagation of SLAP tears by studying the mechanical behavior of the torn superior glenoid labrum. A previously validated finite element model was extended to include a glenoid labrum with type II SLAP tears of three different sizes. The strain distribution within the torn labral tissue with loading applied to the biceps tendon was investigated and compared to the inact and unloaded conditions. The anterior and posterior edges of each SLAP tear experienced the highest strain in the labrum. Labral strain increased with increasing biceps tension. This effect was stronger in the labrum when the size of the tear exceeded the width of the biceps anchor on the superior labrum. Thus, this study indicates that biceps tension influences the propagation of a SLAP tear more than it does the initiation of a tear. Additionally, it also suggests that the tear size greater than the biceps anchor site as a criterion in determining optimal treatment of a type II SLAP tear. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 33:1545–1551, 2015.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/113101/1/jor22888.pd

Impact Response Comparison Between Parametric Human Models and Postmortem Human Subjects with a Wide Range of Obesity Levels

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/138906/1/oby21947_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/138906/2/oby21947.pd

Multimodal endoscopic system based on multispectral and photometric stereo imaging and analysis

We propose a multimodal endoscopic system based on white light (WL), multispectral (MS), and photometric stereo (PS) imaging for the examination of colorectal cancer (CRC). Recently, the enhancement of the diagnostic accuracy of CRC colonoscopy has been reported; however, tumor diagnosis for a variety of lesion types remains challenging using current endoscopy. In this study, we demonstrate that our developed system can simultaneously discriminate tumor distributions and provide three-dimensional (3D) morphological information about the colon surface using the WL, MS, and PS imaging modalities. The results demonstrate that the proposed system has considerable potential for CRC diagnosis. © 2019, OSA - The Optical Society. All rights reserved.1

Helicopter Parenting Versus Autonomy Supportive Parenting? A Latent Class Analysis of Parenting Among Emerging Adults and Their Psychological and Relational Well-Being

We aim to identify typologies of parenting among emerging adults and describe how parenting typologies are related to their life satisfaction, self-efficacy, and parent-child relationship. Using a three-step latent class approach, we analyzed 472 mother-child and 426 father-child relations. We recruited the students from a private university in Upstate New York. We confirmed four parenting classes among emerging adult mothers and fathers: helicopter parenting, autonomy supportive parenting, uninvolved parenting, and parenting that combined characteristics of helicopter parenting and autonomy supportive parenting. We found that emerging adults whose parents were in the autonomy supportive parenting class reported higher scores on life satisfaction, self-efficacy, and their relationship with their parents than those in the helicopter parenting and uninvolved parenting classes. In addition, we found that emerging adults in the combined parenting class reported higher scores for life satisfaction and their relationship with their parents than those in the autonomy supportive parenting class. </jats:p

Drivers of consumer-based brand equity: a two-country analysis of perceived brand origin and identity expressiveness

PurposeThe purpose of this study is to investigate whether and how the effects of cognitive, sensory and affective brand associations on brand love (a core driver of brand loyalty) differ by perceived brand origin (domestic vs imported) and identity expressiveness (low vs high) in two different national contexts.Design/methodology/approachThe data for this study were collected through an online survey in the US and China. A total of 711 responses (n = 362 for the US, n = 349 for China) were used for data analysis. A multiple-group structural equation modeling was used to test the hypotheses.FindingsCognitive and sensory associations are significant drivers of US consumers' brand love while affective associations are important for Chinese consumers' brand love. Also, perceived brand origin and identity expressiveness moderate the three brand associations–brand love relationship. For US consumers, cognitive associations significantly influence brand love for both domestic and imported brands, but sensory associations are important for domestic brand love. For Chinese consumers, affective associations significantly influence brand love for both domestic and imported brands, but cognitive associations are important for imported brand love. The impacts of the three brand associations on brand love differ by the degree of identity expressiveness.Research limitations/implicationsThis empirical study offers important insights into the differing effects of perceived brand origin and identity expressiveness in enhancing brand love across cultures in order to establish strong international brand equity.Originality/valueThis study contributes to the scarce cross-cultural research on brand equity by testing the extended brand equity model. The findings provide more specific, meaningful insights into the role of perceived brand origin and identity expressiveness, leading to more effective international brand management.</jats:sec