Electromyographic Analysis of Trunk Muscle Activation During a Throwing Pattern Following Rotator Cuff Mobilization

Correct muscular activation of the body segments during an overhand throw is achieved when movement originates in the larger and more proximal legs and trunk and moves sequentially to the smaller, distal segments of the shoulder and arm. This sequence permits angular velocity to transfer progressively through the throw as part of an open kinetic chain. The athlete can summate angular velocity and segmental forces only if he is able to create a separation between the body segments during the movement pattern, and this separation is thus essential to effective segmental sequencing for activation of the trunk muscles to occur separately from distal segment motion. Limited mobility of the shoulder and scapula during the kinematic sequence will limit the ability of that segment to receive and contribute to the angular velocity of its proximal neighbors and to apply its own muscle torque to the throwing implement. This may result in compensatory motion of the proximal muscle groups to meet the demands placed on the body. To establish a link between compensatory activation of the trunk muscles and mobility in the rotator cuff and to apply this relationship to the pattern of the overhand throw, activity in the latissimus dorsi and external oblique/quadratus lumborum muscles was measured using surface electromyography in 40 college-age participants during arm flexion and lateral shoulder rotation. Muscle activation was recorded both before and after mobilization of relevant throwing muscles through targeted functional exercise. Results showed no significant change but suggested a general decrease in the level of peak muscle activation after participants engaged shoulder exercises. This is indicative of a downward trend in compensatory trunk activation during the initiation of shoulder motion. An increase in overall trunk muscle activity was also observed after exercise, which may imply a simultaneous engagement of the proximal throwing muscles in response to shoulder motion

Erratum: Prevalence and distribution of selected cervical human papillomavirus types in HIV infected and HIV uninfected women in South Africa, 1989–2021: A narrative review

No abstract available

Feasibility and acceptability of self-collection of Human Papillomavirus samples for primary cervical cancer screening on the Caribbean Coast of Nicaragua: A mixed-methods study

BackgroundCervical cancer is the primary cause of cancer death for women in Nicaragua, despite being highly preventable through vaccination against high-risk genotypes of the Human Papillomavirus (hrHPV), screening for hrHPV, and early detection of lesions. Despite technological advances designed to increase access to screening in low resource settings, barriers to increasing population-level screening coverage persist. On the Caribbean Coast of Nicaragua, only 59% of women have received one lifetime screen, compared to 78.6% of eligible women living on the Pacific and in the Interior. In concordance with the WHO’s call for best practices to eliminate cervical cancer, we explored the feasibility and acceptability of self-collection of samples for hrHPV testing on the Caribbean Coast of Nicaragua through a multi-year, bi-national, community-based mixed methods study.MethodsBetween 2016 and 2019, focus groups (n=25), key informant interviews (n=12) [phase I] and an environmental scan [phase II] were conducted on the Caribbean Coast of Nicaragua in partnership and collaboration with long-term research partners at the University of Virginia and community-based organizations. In spring 2020, underscreened women on the Caribbean Coast of Nicaragua were recruited and screened for hrHPV, with the choice of clinician collection or self-collection of samples.ResultsOver the course of the study, providers and potential patients expressed significant acceptability of self-collection of samples as a strategy to reduce barriers currently contributing to the low rates of screening (phases I and II). Ultimately 99.16% (n=1,767) of women chose to self-collect samples, demonstrating a high level of acceptability of self-collection in this pilot sample (phase III). Similarly, focus groups, key informant interviews, and the environmental scan (phases I and II) of resources indicated critical considerations for feasibility of implementation of both HPV primary screening and subsequently, self-collection of samples. Through phase III, we piloted hrHPV screening (n=1,782), with a 19.25% hrHPV positivity rate.ConclusionSelf-collection of samples for hrHPV testing demonstrated high acceptability and feasibility. Through concerted effort at the local, regional, and national levels, this project supported capacity building in reporting, monitoring, and surveilling cervical cancer screening across the continuum of cervical cancer control

Use of airborne PM10 concentrations at air quality monitoring sites in Imperial County, California, as an indication of geographical influences on lung health during drought periods: a time-series analysis

Background: 2012–16 marked the worst drought in California, USA, in more than a century. Droughts are expected to recur in broader areas as a result of anthropogenic climate change. The Salton Sea, a landlocked depression without natural river inflow, is almost entirely dependent on agricultural irrigation of Imperial Valley's 475 000 acres of farmland, although its water level has been diminishing because of decreased precipitation and river flow. Exposure of the lakebed and ground heating in an already arid climate might cause an increase in airborne PM10 (particulate matter less than 10 μm in diameter), reactive nitrogen, and ground-level ozone, exacerbating asthma symptoms. During the most severe drought years, admissions of children to the emergency department for asthma-related symptoms in Imperial County were among the highest in California and double the number for the entire state. However, previous analyses have not taken into account environmental mediators with more specific geographical granularity than the county level. Methods: In this analysis, we used 2006–16 data from the US Drought Monitor and the five air quality monitoring stations (AQMS) within Imperial County, CA, USA. To reconcile sampling differences between 7-day drought severity reports and 6-day PM10 measurements, a date windowing function was applied to match each PM10 measurement to the drought severity value at the most closely related point in absolute time. Upon visually examining the data, lower concentrations of PM10 appeared to drive the correlation between AQMS. Therefore, in two time series—all years and non-drought years only—all concentrations of PM10 that were lower than 75 ppm were removed, and the remaining concentrations were used to measure correlations between AQMS. Findings: PM10 concentrations across all years were poorly correlated between AQMS (r=0·41–0·80; p<0·05). When removing PM10 concentrations lower than 75 ppm and examining only the remaining values, the correlation coefficients for these values decreased (r=0·16–0·53; p<0·05). When removing drought years (2012 onwards), these values were slightly more correlated in comparisons between some AQMS than across all observed years (r=0·46–0·77; p<0·05). Interpretation: The inconsistency in PM10 concentrations between AQMS on high PM10 days and during drought years suggests that different AQMS do not experience the same changes in air quality, particularly on days most likely to cause asthma exacerbations. This finding indicates a geographical component of air-quality differences and the potential for children near rural farmland to be more susceptible to asthma and lung disease. Future research regarding respiratory health in drought areas will provide a perspective on under-represented local and regional environmental challenges. Drought is one of the most expensive natural events from a number of economic and public health stances, and findings in support of the health implications of agriculture and water use have broader potential implications for water policy, drought mitigation strategies, and health improvement. Funding: None

Nutritional Avocado Intervention Improves Physical Activity Measures in Hispanic/Latino Families: A Cluster RCT

IntroductionNutrition and physical activity are key components for the prevention of cardiovascular disease. There remains a paucity of trial data on the effect of specific nutritional interventions on physical activity and sedentary time. One question is how a common nutrient-dense food such as avocado may impact physical activity and sedentary time in Hispanic/Latino families, a group that reports the lowest levels of physical activity.DesignThis is a 6-month clustered RCT.Setting/participantsSeventy-two families (235 individuals) who identified as Hispanic/Latino were enrolled through the San Ysidro Health Center (San Diego, CA) between April 2017 and June 2018.InterventionAfter a 2-week run-in period, 35 families were randomized to the intervention arm (14 avocados/family/week), and 37 families were assigned to the control arm (3 avocados/family/week).Main outcome measuresLinear mixed-effects models were used to assess changes in physical activity (MET minutes per week) between the groups during the 6-month trial. Secondary outcomes included sedentary time (minutes/week), BMI, and systolic and diastolic blood pressures.ResultsAn adherence goal of &gt;80% was achieved for both arms. Total mean physical activity increased by 2,197 MET minutes per week more in the intervention group (p&lt;0.01) than in the control group, driven by between-group differences in moderate (p&lt;0.01) versus vigorous (p=0.06) physical activity. After accounting for longitudinal repeated measures per participant and nested family effects, total adult physical activity remained significantly higher in the intervention than in the control group (+1,163 MET minutes per week on average per participant), with a significant intervention interaction term (p&lt;0.01). There were no significant changes in sedentary time, BMI, or blood pressure.ConclusionsHigher allocation of avocados was associated with significantly higher physical activity and no adverse changes in BMI or blood pressure, suggesting that this nutritional intervention may have beneficial pleiotropic effects.Trial registration: This study is registered at www.clinicaltrials.gov as NCT02903433

Retinal Thickening and Photoreceptor Loss in HIV Eyes without Retinitis

<div><p>Purpose</p><p>To determine the presence of structural changes in HIV retinae (i.e., photoreceptor density and retinal thickness in the macula) compared with age-matched HIV-negative controls.</p><p>Methods</p><p>Cohort of patients with known HIV under CART (combination Antiretroviral Therapy) treatment were examined with a flood-illuminated retinal AO camera to assess the cone photoreceptor mosaic and spectral-domain optical coherence tomography (SD-OCT) to assess retinal layers and retinal thickness.</p><p>Results</p><p>Twenty-four eyes of 12 patients (n = 6 HIV-positive and 6 HIV-negative) were imaged with the adaptive optics camera. In each of the regions of interest studied (nasal, temporal, superior, inferior), the HIV group had significantly less mean cone photoreceptor density compared with age-matched controls (difference range, 4,308–6,872 cones/mm²). A different subset of forty eyes of 20 patients (n = 10 HIV-positive and 10 HIV-negative) was included in the retinal thickness measurements and retinal layer segmentation with the SD-OCT. We observed significant thickening in HIV positive eyes in the total retinal thickness at the foveal center, and in each of the three horizontal B-scans (through the macular center, superior, and inferior to the fovea). We also noted that the inner retina (combined thickness from ILM through RNFL to GCL layer) was also significantly thickened in all the different locations scanned compared with HIV-negative controls.</p><p>Conclusion</p><p>Our present study shows that the cone photoreceptor density is significantly reduced in HIV retinae compared with age-matched controls. HIV retinae also have increased macular retinal thickness that may be caused by inner retinal edema secondary to retinovascular disease in HIV. The interaction of photoreceptors with the aging RPE, as well as possible low-grade ocular inflammation causing diffuse inner retinal edema, may be the key to the progressive vision changes in HIV-positive patients without overt retinitis.</p></div

Baseline demographic characteristics.

<p>Baseline demographic characteristics.</p

SD-OCT scans of A. HIV-positive, and B. HIV-negative control, showing total retinal thickness measurements.

<p>Top red line corresponds to the internal limiting membrane (ILM) and bottom red line corresponds to the Bruch’s membrane (BM).</p

Analysis of three B-scans within the raster scan set.

<p>The first was centered on the fovea (F), the second was 10 scans superior to the fovea (S), and the third was 10 scans inferior to the fovea (I). For each scan, thickness was measured at the center and over a length of 1,000 microns equally split over the center (red lines).</p