ASSOCIATIONS BETWEEN GLENOHUMERAL ROTATION STRENGTH AND SELECT KINETIC PARAMETERS DURING THE BASEBALL PITCH IN ADOLESCENT BASEBALL PITCHERS

The purpose of this study was to examine the associations between isometric glenohumeral rotation strength and select biomechanical parameters during the pitching motion in adolescent baseball pitchers. Glenohumeral (GH) rotation strength and pitching kinetic data were assessed in 28 (14.2 ±0.94 yrs; 66.5 ±11.7 kg; 175 ±10.8 cm) adolescent baseball pitchers. Spearman’s rank correlations were used to assess relationships between GH rotation strength and upper extremity torques during the pitching motion. Peak GH internal rotation torque during the pitch was negatively correlated with the ratio of throwing arm external rotation strength to non-throwing arm external rotation strength (r= -0.552, p \u3c 0.05). These results provide evidence for a potential mechanism behind the increased injury risk seen in pitchers who exhibit GH external rotation weakness

Effect of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker initiation on organ support-free days in patients hospitalized with COVID-19

IMPORTANCE Overactivation of the renin-angiotensin system (RAS) may contribute to poor clinical outcomes in patients with COVID-19. Objective To determine whether angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) initiation improves outcomes in patients hospitalized for COVID-19. DESIGN, SETTING, AND PARTICIPANTS In an ongoing, adaptive platform randomized clinical trial, 721 critically ill and 58 non–critically ill hospitalized adults were randomized to receive an RAS inhibitor or control between March 16, 2021, and February 25, 2022, at 69 sites in 7 countries (final follow-up on June 1, 2022). INTERVENTIONS Patients were randomized to receive open-label initiation of an ACE inhibitor (n = 257), ARB (n = 248), ARB in combination with DMX-200 (a chemokine receptor-2 inhibitor; n = 10), or no RAS inhibitor (control; n = 264) for up to 10 days. MAIN OUTCOMES AND MEASURES The primary outcome was organ support–free days, a composite of hospital survival and days alive without cardiovascular or respiratory organ support through 21 days. The primary analysis was a bayesian cumulative logistic model. Odds ratios (ORs) greater than 1 represent improved outcomes. RESULTS On February 25, 2022, enrollment was discontinued due to safety concerns. Among 679 critically ill patients with available primary outcome data, the median age was 56 years and 239 participants (35.2%) were women. Median (IQR) organ support–free days among critically ill patients was 10 (–1 to 16) in the ACE inhibitor group (n = 231), 8 (–1 to 17) in the ARB group (n = 217), and 12 (0 to 17) in the control group (n = 231) (median adjusted odds ratios of 0.77 [95% bayesian credible interval, 0.58-1.06] for improvement for ACE inhibitor and 0.76 [95% credible interval, 0.56-1.05] for ARB compared with control). The posterior probabilities that ACE inhibitors and ARBs worsened organ support–free days compared with control were 94.9% and 95.4%, respectively. Hospital survival occurred in 166 of 231 critically ill participants (71.9%) in the ACE inhibitor group, 152 of 217 (70.0%) in the ARB group, and 182 of 231 (78.8%) in the control group (posterior probabilities that ACE inhibitor and ARB worsened hospital survival compared with control were 95.3% and 98.1%, respectively). CONCLUSIONS AND RELEVANCE In this trial, among critically ill adults with COVID-19, initiation of an ACE inhibitor or ARB did not improve, and likely worsened, clinical outcomes. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT0273570

Comparing Infant Hip Joint Center Estimations Between Manual and Digital Measures

Comparing Infant Hip Joint Center Estimations Between Manual and Digital MeasuresDespite the high prevalence of developmental hip disorders in infants, there has been little research on understanding infant hip anatomy. The hip joint center (HJC) is the center of rotation of the hip joint, usually assumed to be the center of the femoral head, and it is the critical location for calculating moments and forces about the hip joint. The HJC cannot be externally identified, and thus localization requires diagnostic imaging or approximation when using motion capture systems. Approximations are calculated from regression equations dependent on anthropometric data and anatomical landmarks. None of the current regression equations are based on infant anatomy. The purpose of this study was to determine whether the HJC estimation equations recommended by the International Society of Biomechanics yield comparable results when tested on a 3-dimensional (3D) digital model and a 3D physical model of the infant hip. Anatomical positions needed for the computation of the HJC were identified in the digital and physical models. Ten measures were collected on each model and the HJC was estimated using the four Bell methods. An independent samples T-test was performed for each dataset. No significant differences in HJC estimations were found between the manual and digital measures for each method. This indicates that anatomical landmarks utilized in a digital model are comparable to a physical model and supports that the use of manual measurements may be viable for estimating the infant HJC in clinical settings where diagnostic imaging is unavailable. The lack of significant findings may partially be due to the fact that only one model was tested, thus we were unable to compare between subjects. Additionally, the current models were bone-only and lacked representation of soft-tissue, which may have altered our results. Further testing with more robust models and methods are needed to confirm the results. This study serves as preliminary research in the development of HJC estimation standards for infants

Identifying Strategies Used to Negotiate Stairs When Carrying an Infant Surrogate

For the first year of life, humans depend on caregivers to transport them. While carrying infants in arms, wraps, or carriers on a parent’s body have been used for centuries, modern infant product design has introduced alternative methods to carry infants including car seats and strollers. However, it is unclear how these different carrying methods may impact a caregiver’s biomechanics or risks of injury. The objective of this study is to identify strategies used when negotiating stairs with a 12 pound infant manikin. An outdoor obstacle course was designed, representing typical activities required to navigate urban architecture: ascending and descending stairs and ramps, entering and exiting buildings, and crossing curbs. The course was completed by ten healthy female participants (aged 21-24 years). A pre-testing questionnaire was completed by each participant to screen out potential participants who were mothers or who had current injuries and/or pain. All participants were injury and pain free. No participant was a mother or had been previously pregnant. Participants carried an infant manikin in a carrier, car seat, stroller, and in arms through the urban obstacle course. Each carrying method was completed six times, three times forward and three times backwards through the course. High-speed video cameras filmed each obstacle along the course. This abstract focuses only on the stair obstacle. Three investigators watched fifty randomly selected trials and identified them. A total of 240 trials were collected. Six trials had to be excluded due to equipment malfunctions. The breakdown of device conditions of the remaining 234 trials were 59 in arms, 59 in a carrier, 60 in a car seat, and 56 in a stroller. Investigators watched 50 random trials and denoted movement strategies for each carrying condition based on defining characteristics. When carrying the infant manikin in arms four main strategies were observed; carrying on the hip with a single arm (dominant or non-dominant) with and without support from the second arm. When walking with the manikin in a baby carrier three main strategies were observed: arms hanging freely, arms wrapped around the carrier providing additional support, and arms resting on the carrier providing little to no support. Six strategies were identified in the car seat condition: carrying the car seat at the elbow (dominant and nondominant) with and without support from the second arm (support), a mixed grip, and a single arm “lock” grip. Five strategies were identified in the stroller condition: a forward push, a backwards pull, a front wheel pop, carrying, and a step by step carry. A “switch” and an “other” category were added to each condition for cases when a participant transferred between strategies or used a strategy not defined above. The most commonly employed strategy across all conditions was free hanging arms when the manikin was in a carrier. Free arms were seen in 45.8% of trials in the carrier condition. In the in arms condition the single arm (dominant) + support was the most commonly employed strategy accounting for 44.1% of all in arms trials. The most common strategy for carrying the car seat was carrying at the elbow (dominant) + support, which was observed in 25% of the car seat trials. Carrying the stroller was the most common strategy implemented in the stroller condition, and accounted for 35.7% of stroller trials. There was more variability in the strategies chosen for the car seat and stroller conditions than the in arms or carrier conditions during stair negotiation. This may be attributed to a relative lack of infant care experience in the participants. The car seat and stroller were also the bulkiest carrying devices which may have increased carrying difficulty. This may have contributed to participants changing between carrying strategies across trials and within trials. Greater consistency may be seen in future studies conducted on mothers and other primary caregivers of infants