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Background: Excessive shoulder anterior force has been implicated in pathology of the rotator cuff in little league and professional baseball pitchers; in particular, anterior laxity, posterior stiffness, and glenohumeral joint impingement. Distinctly characterized motions associated with excessive shoulder anterior force remain poorly understood. Methods: High school and professional pitchers were instructed to throw fastballs while being evaluated with 3D motion capture (480 Hz). A supplementary random forest model was designed and implemented to identify the most important features for regressing to shoulder anterior force, with subsequent standardized regression coefficients to quantify directionality. Results: 130 high school pitchers (16.3 ± 1.2 yrs; 179.9 ± 7.7 cm; 74.5 ± 12.0 kg) and 322 professionals (21.9 ± 2.1 yrs; 189.7 ± 5.7 cm; 94.8 ± 9.5 kg) were included. Random forest models determined nearly all the variance for professional pitchers (R2 = 0.96), and less than half for high school pitchers (R2 = 0.41). Important predictors of shoulder anterior force in high school pitchers included: trunk flexion at maximum shoulder external rotation (MER) (X.IncMSE = 2.4, β = −0.23, p < 0.001), shoulder external rotation at ball release (BR)(X.IncMSE = 1.7, β = −0.34, p < 0.001), and shoulder abduction at BR (X.IncMSE = 3.1, β = 0.17, p < 0.001). In professional pitchers, shoulder horizontal adduction at foot contact (FC) was the highest predictor (X.IncMSE = 13.9, β = 0.50, p < 0.001), followed by shoulder external rotation at FC (X.IncMSE = 3.6, β = 0.26, p < 0.001), and maximum elbow extension velocity (X.IncMSE = 8.5, β = 0.19, p < 0.001). Conclusion: A random forest model successfully selected a subset of features that accounted for the majority of variance in shoulder anterior force for professional pitchers; however, less than half of the variance was accounted for in high school pitchers. Temporal and kinematic movements at the shoulder were prominent predictors of shoulder anterior force for both groups. Clinical relevance: : Our statistical model successfully identified a combination of features with the ability to adequately explain the majority of variance in anterior shoulder force among high school and professional pitchers. To minimize shoulder anterior force, high school pitchers should emphasize decreased shoulder abduction at BR, while professionals can decrease shoulder horizontal adduction at FC. [ABSTRACT FROM AUTHOR]

Background: Subacromial balloon spacers have been introduced as a potential treatment option for patients with massive irreparable rotator cuff tears. However, it is important to comprehensively assess the clinical efficacy of this procedure in the context of an increasing amount of contemporary literature. Purpose: To perform a systematic review of the contemporary literature to understand the propensity for clinically meaningful improvements after subacromial balloon spacer implantation for massive irreparable rotator cuff tears. Study Design: Systematic review and meta-analysis; Level of evidence, 4. Methods: The PubMed, Ovid/MEDLINE, and Cochrane databases were queried in July 2022 for data pertaining to studies reporting clinically significant outcomes after subacromial balloon spacer implantation. Freeman-Tukey double arcsine transformation was used to quantify the pooled rate of clinically meaningful improvements in outcomes as evaluated using the minimal clinically important difference (MCID), Patient Acceptable Symptom State (PASS), and substantial clinical benefit (SCB). Qualitative analysis was performed when data were variably presented to avoid misleading reporting. Results: There were 10 studies included, all of which reported MCID achievement. The overall pooled rate of MCID achievement for the Constant-Murley score was 83% (95% CI, 71%-93%; range, 40%-98%), with 6 of 8 studies reporting rates equal to or exceeding 85%. One study reported a 98% rate of PASS achievement for the Constant-Murley score at 3-year follow-up. The rate of MCID achievement for the American Shoulder and Elbow Surgeons (ASES) score ranged between 83% and 87.5%. The rate of PASS achievement for the ASES score was 56% at 2-year follow-up, while the rate of SCB achievement for the ASES score was 83% and 82% at 1- and 2-year follow-up, respectively. At 1-year follow-up, 74% and 78% of patients achieved the MCID for the Numeric Rating Scale and Oxford Shoulder Score, respectively. At 3 years, 69% of patients achieved the MCID for the Numeric Rating Scale and 87% achieved it for the Oxford Shoulder Score. Conclusion: Patients who underwent isolated subacromial balloon spacer implantation for massive irreparable rotator cuff tears demonstrated a high rate of clinically significant improvement in outcomes at short- to mid-term follow-up. A paucity of literature exists to appropriately define and evaluate the rates of achieving the PASS and SCB after subacromial balloon spacer implantation, necessitating further study. [ABSTRACT FROM AUTHOR]

The purposes of this study were (a) to analyze the changes in total and regional body composition measurements in a National Collegiate Athletic Association (NCAA) Division I female field hockey team throughout a 17-game competitive season using dual X-ray absorptiometry (DXA); (b) to examine improvements, if any, in athletic performance measures after a season; and (c) to report on the relationship between these body composition changes and changes in athletic performance. Preseason and postseason dual-energy DXA and performance data from the 2019-2020 season were retrospectively identified for 20 field players (forwards, midfielders, and defenders). Body composition data included total and regional fat mass, lean mass, and body fat percentage, whereas athletic performance measures included the vertical jump, 10-yard dash, and pro-agility (5-10-5) shuttle run. All variables were quantitative and analyzed using paired t-tests or its nonparametric equivalent and an alpha level of p, 0.05 was used to determine significance. After a competitive season, athletes had significant decreases in fat mass and increases in lean mass in their arms, legs, trunks, gynoids, and total body measurements. Android fat mass and body fat percentage also decreased. Athletes performed significantly better on the pro-agility shuttle run at the end of the season, but no significant differences were observed in other performance metrics. Moderate correlations were observed between changes in body composition (total fat mass and total lean mass) and changes in athletic performance. Our study provides a novel, longitudinal assessment of body composition and athletic performance for elite female field hockey athletes that will help trainers and coaches better understand how these variables change throughout a season and allow them to better prepare their players for competitive success. [ABSTRACT FROM AUTHOR]

Background: Biodegradable subacromial balloon spacers (SBSs) have become increasingly used for the treatment of massive irreparable rotator cuff tears given their theorized clinical benefits; however, the relationship between biomechanical functions of the balloon spacer and clinical benefits remains unclear. Purpose: To perform a systematic review and meta-analysis of controlled laboratory studies investigating the use of SBSs for massive irreparable rotator cuff tears. Study Design: Systematic review and meta-analysis; Level of evidence, 4. Methods: PubMed, OVID/Medline, and Cochrane databases were queried in July 2022 for biomechanical data pertaining to SBS implantation in cadaveric models of irreparable rotator cuff tears. Random-effects meta-analysis of continuous outcomes using the DerSimonian-Laird method was performed to estimate pooled-treatment effect sizes between the irreparable rotator cuff tear state and the state in which an SBS was implanted. Data reported variably or in formats not amenable to analysis were presented descriptively. Results: Five studies involving 44 cadaveric specimens were included. At 0° of shoulder abduction, SBS implantation resulted in a mean inferior humeral head translation of 4.80 mm (95% CI, 3.20-6.40; P <.001) relative to the irreparable rotator cuff tear state. This decreased to 4.39 mm and 4.35 mm at 30° and 60° of abduction, respectively. At 0° of abduction, implantation of an SBS was associated with a 5.01-mm (95% CI, 3.56-6.46, P <.001) anterior translation of the glenohumeral center of contact pressure relative to the irreparable tear state. This translation changed to 5.11 mm and 5.49 mm at 30° and 60° of abduction. In 2 studies, SBS implantation restored the glenohumeral contact pressure to that of the intact state and significantly reduced subacromial pressure distribution over a rotator cuff repair state. In 1 study, a high balloon fill volume (40 mL) resulted in a significant 10.3 ± 1.4–mm more anterior humeral head position relative to the intact cuff state. Conclusion: SBS implantation in cadaveric models of irreparable rotator cuff tears results in significant improvements in humeral head position at 0°, 30°, and 60° of shoulder abduction. Balloon spacers may also improve glenohumeral and subacromial contact pressures, although insufficient evidence currently exists to corroborate these findings. High balloon fill volumes (40 mL) may confer supraphysiologic anteroinferior translation of the humeral head. [ABSTRACT FROM AUTHOR]

To determine if posteromedial tibial plateau (PMTP) bone bruising on pre-operative MRI is significantly associated with a ramp lesion identified during arthroscopy in patients with concomitant ACL ruptures. PubMed, CINAHL, Scopus, Web of Sciences, EMBASE, and Cochrane Library were searched systematically for studies that investigated the association between PMTP bone bruises on preoperative MRI and ramp lesions confirmed during arthroscopy. Eight studies met inclusion criteria. The Methodological Index for Nonrandomized Studies (MINORS) checklist was used to assess quality. A meta-analysis was performed to analyze odds of a ramp lesion after PMTP bone bruising identified on magnetic resonance imaging (MRI). Publication bias was assessed by funnel plot and Egger's linear regression test. There are 2.05 greater odds of medial meniscal ramp lesions in patients with an ACL rupture when PMTP bone bruising is found on preoperative MRI (95% CI, 1.29–3.25; p = 0.002). Heterogeneity of the pooled studies may be substantial (I2 = 65%; p = 0.006). Funnel plot analysis and Egger's linear regression test (p > 0.5) determined no publication bias among the studies included in the meta-analysis. Patients with acute ACL injuries and PMTP bone bruising on MRI have 2.05 times greater odds of a concomitant medial meniscal ramp lesion than those without this bone bruise pattern. [ABSTRACT FROM AUTHOR]