EMG Analysis of Latissimus Dorsi, Middle Trapezius, and Erector Spinae Muscle Activity during Return to Neutral Phase of Spinal Rotation

Purpose/Hypothesis: Rotation of the spine is a common movement used to perform activities of daily living and sports performance, and contributes to a large percentage of low back injuries. Performance of spinal rotation for the rehabilitation and prevention of future back injuries should be considered, as low back pain is the second most common reason for a physician visit. Muscles that are involved in rotation of the spine have been studied, but the Latissimus Dorsi (LD) has limited research on the influence of spinal rotation. The LD muscle is one of the largest back muscles and influences many movements of the trunk and limbs, and many attachment sites including the humerus, pelvis, ribs, spine, and scapula. The purpose of this study is to understand the muscle activity of the LD, middle trapezius (MT), and erector spinae (ES) during the movement from full hip rotation to neutral in a standing (non-fixed) and quadruped (fixed) position. Materials/Methods: Twenty-six healthy subjects (17 female) between 20-40 years of age volunteered to be a part of this study. All muscle activity being tested in this study was recorded using surface EMG electrodes while the subject performed left and right spinal rotation in standing and quadruped positions. Four spinal rotation test positions (standing rotation right/left, quadruped rotation right/left) were initiated by movement at the pelvis. A Maximal Voluntary Contraction (MVC) recorded in the prone position was used to normalize the muscle activity of the muscles being tested, and findings were analyzed for significance at ⍺=0.05. EMG data was collected and analyzed using Noraxon MyoResearchXP software. Results: Statistically significant differences were present in the ipsilateral and contralateral LD with upper extremities in a fixed position compared to non-fixed during the movement from full hip rotation to neutral. The mean EMG activity of the right LD was greater than the bilateral MT and ES in left return to neutral rotation with upper extremities in a fixed position, and the left LD was more active than bilateral MT and ES in right return to neutral rotation in the same fixed position. The EMG activity of the MT in all standing and quadruped return to neutral movements of spinal rotation was significantly less than the LD and ES. Lastly, in the standing position, the ES was significantly more active in both ipsilateral and contralateral return to neutral spinal rotation than bilateral LD and MT. Discussion/Conclusion: Our findings suggest that the LD significantly contributes to the return to neutral phase of spinal rotation in the quadruped position. The MT did not have a significant influence on the return to neutral phase of spinal rotation in any position, and the ES played a greater role in standing. Results of this study correlate with ongoing studies regarding the LD’s activation during the concentric phase of spinal rotation, and isometric lifting activities. Future research could include comparisons between healthy subjects and individuals who are experiencing low back pain. Clinical Relevance: This study assessed the contribution of the LD in comparison to the MT and ES during spinal rotation. Furthermore, this study particularly analyzed the LD activation and nearby musculature during the return to neutral phase of rotation. Our findings concluded that with fixed upper extremities the contralateral LD should be considered a major contributor during the return to neutral phase of spinal rotation with fixed upper extremities. Many activities throughout the day utilize spinal rotation with fixed upper extremities in the quadruped position, such as getting out of bed or up off the floor, supporting the statement that strength and mobility assessments of the LD should become a part of comprehensive evaluations by clinicians

Powerful Relationships in Leadership: A Collection of Modern Leadership Insights

Powerful Relationships in Leadership caters to front runners of the leadership world who are looking for fresh perspectives into how to properly organize and create trailblazing organizations. This book is a collection of articles on aspects of leading. It separates itself from other management texts by offering perceptions of entry level personnel. It is our hope that you will begin to appreciate how entry level personnel view management and their role in guiding administrators.https://openriver.winona.edu/leadershipeducationbooks/1001/thumbnail.jp

More than competition: exploring stakeholder identities at a grassroots cause-related sporting event

The purpose of this paper is to (a) explore stakeholder identities of a grassroots cause-related sporting event; and (b) gain a better understanding of how identities are related to stakeholder development, support of the event, and future intentions. We used a mixed methods research design that consisted of two studies: qualitative followed by quantitative. Study 1 explored stakeholder identities and how they are related to stakeholder development and support of the event, and Study 2 examined how future intentions regarding attendance, donations, and sponsor support differ based on levels of stakeholder identity. Sports marketing and non-profit management literature streams as well as identity theory and social capital theory informed our studies. The National Kidney Foundation Surf Festival was selected because it is a grassroots cause-related sporting event with financial success over the last two decades. In addition, a surf contest, an action sport, is a unique sport setting in the nonprofit sector, which offers insight to marketers seeking to target subcultures. The findings of the qualitative study revealed three identities relevant to participants: sport subculture, community, and cause. A framework emerged from the data that illustrated how these identities unite together to generate social capital, which is linked to effective volunteer and sponsorship management. Quantitative analysis through survey data provided further evidence of the impact of identification with a cause-related sport activity on consumer outcomes. Results indicated attendees with high surf-related identity are more likely to attend future Surf Festivals, have higher intentions to donate to the cause, and have higher sponsor purchase intentions compared to those with low self-identity with the sport subculture. The conclusion discusses implications, framing the findings through the intersection of the sports marketing and non-profit sector industries, and provides suggestions for future research.Ye

Characterization of Indoor Air Quality on a College Campus: A Pilot Study

Recent construction trends on college campuses have demonstrated a shift to designing buildings with features focused on sustainability. However, few studies have investigated indoor air quality in institutions of higher education, particularly in sustainably designed buildings. The objective of this study was to evaluate the association of building and occupancy on indoor air quality within and between higher education buildings. We measured particulate matter, formaldehyde, carbon dioxide, and nitrogen oxides in LEED certified, retrofitted, and conventional building types on a college campus. Three size fractions of particulate matter were measured in each building. We conducted multi-zonal, 48-h measurements when the buildings were occupied and unoccupied. Outdoor particulate matter was significantly higher (PM2.5 = 4.76, PM4 = 17.1, and PM100 = 21.6 µg/m3) than in classrooms (PM2.5 = 1.7, PM4 = 4.2, and PM100 = 6.7 µg/m3) and common areas (PM2.5 = 1.3, PM4 = 4.2, and PM100 = 4.8 µg/m3; all p < 0.001). Additionally, concentrations of carbon dioxide and particulate matter were significantly higher (p < 0.05) during occupied sampling. The results suggest that occupancy status and building zone are major predictors of indoor air quality in campus buildings, which can, in turn, increase the concentration of contaminants, potentially impacting occupant health and performance. More research is warranted to reveal building features and human behaviors contributing to indoor exposures

Association of Phenotypic Aging Marker with comorbidities, frailty and inflammatory markers in people living with HIV

Abstract Background Aging characteristics in people living with HIV (PLWH) are heterogeneous, and the identification of risk factors associated with aging-related comorbidities such as neurocognitive impairment (NCI) and frailty is important. We evaluated predictors of novel aging markers, phenotypic age (PhenoAge) and phenotypic age acceleration (PAA) and their association with comorbidities, frailty, and NCI. Methods In a cohort of PLWH and age- and sex-matched HIV-negative controls, we calculated PhenoAge using chronological age and 9 biomarkers from complete blood counts, inflammatory, metabolic-, liver- and kidney-related parameters. PAA was calculated as the difference between chronological age and PhenoAge. Multivariate logistic regression models were used to identify the factors associated with higher (>median) PAA. Area under the receiver operating characteristics curve (AUROC) was used to assess model discrimination for frailty. Results Among 333 PLWH and 102 HIV-negative controls (38% female), the median phenotypic age (49.4 vs. 48.5 years, p = 0.54) and PAA (− 6.7 vs. -7.5, p = 0.24) was slightly higher and PAA slightly less in PLWH although this did not reach statistical significance. In multivariate analysis, male sex (adjusted odds ratio = 1.68 [95%CI = 1.03–2.73]), current smoking (2.74 [1.30–5.79]), diabetes mellitus (2.97 [1.48–5.99]), hypertension (1.67 [1.02–2.72]), frailty (3.82 [1.33–10.93]), and higher IL-6 levels (1.09 [1.04–1.15]), but not HIV status and NCI, were independently associated with higher PAA. PhenoAge marker discriminated frailty better than chronological age alone (AUROC: 0.75 [0.66–0.85] vs. 0.65 [0.55–0.77], p = 0.04). In the analysis restricted to PLWH, PhenoAge alone predicted frailty better than chronological age alone (AUROC: 0.7412 vs. 0.6499, P = 0.09) and VACS index (AUROC: 0.7412 vs. 0.6811, P = 0.34) despite not statistically significant. Conclusions While PLWH did not appear to have accelerated aging in our cohort, the phenotypic aging marker was significantly associated with systemic inflammation, frailty, and cardiovascular disease risk factors. This simple aging marker could be useful to identify high-risk PLWH within a similar chronological age group