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An overhead throwing motion is a common gross motor skill often taught in early childhood to improve physical activity participation. Yet, research investigating motor efficiency in overhead throws often focuses on improving performance in trained individuals. This project compares kinematic sequencing between trained and untrained youth. After a brief warm-up, untrained high school students (N = 9) and trained high school and college students (N = 10) threw a weighted tennis ball for accuracy (N = 10 throws). Upper extremity angular velocities were collected using 3-dimensional inertial sensor motion capture. Kinematic sequencing of joints and segments (pelvis, trunk, shoulder, elbow, and wrist) was assessed using Kruskal–Wallis test; Friedman and Wilcoxon tests identified group differences between sequences. Seven independent kinematic sequences were identified (N = 2 unique trained; N = 3 unique untrained; N = 2 shared). The rankings for the trained group maintained a mostly consistent pattern with only elbow and wrist joints producing similar rankings. The untrained group lacked that consistency with similar rankings of elbow versus wrist and shoulder versus elbow. Trained individuals threw with a more efficient proximal-to-distal sequencing pattern than the untrained participants, specifically at the trunk and shoulder. Continuous training of gross motor skills beyond initial skill development is necessary to maintain motor proficiency. [ABSTRACT FROM AUTHOR]

Background: The ulnar collateral ligament (UCL) is frequently injured in overhead throwing athletes, leading to elbow instability, pain and decreased performance, and requiring surgical intervention. Augmenting with suture tape provides a novel approach to UCL repair, offering stability while preserving native anatomy, proprioception, and minimizing bone loss, with the added benefit of an expected faster rehabilitation and return to sport (RTS) compared to traditional UCL reconstruction. The purpose of this study is to assess the variability of the current publicly available rehabilitation protocols for elbow UCL repair with suture tape augmentation. Methods: A systematic review of Google and PubMed was performed to find rehabilitation protocols for UCL repair with suture tape augmentation. Two hundred nine orthopedic surgery residency programs were identified using the Fellowship and Residency Electronic Interactive Database Access. The programs were searched on Google, a broad nonspecific Google search, and a systematic literature search of journal databases for UCL repair with suture tape augmentation rehabilitation protocols was conducted. Results: Thirteen rehabilitation protocols met the inclusion criteria for analysis. Of these, 12 protocols outlined the use of an articulating brace at varying range of motion settings for the first 4-6 weeks following surgery. Return to throwing was included in all 13 protocols and began between 10 and 12 weeks following surgery. RTS was included in 11 protocols and expected athletes competing as early as 16 weeks with a mean recommended RTS at 21.5 weeks. Conclusion: Rehabilitation protocols for UCL repair with suture tape augmentation were often structured around a 5-phase program with RTS approaching 20 weeks. They utilized immobilization and range of motion restriction as well as strengthening and gradual RTS procedures. Overall, the included protocols had mild variability with initiation of throwing and RTS 12 to 24 weeks faster than traditional UCL reconstruction.

Long-term training effects of weighted ball throwing programs have been well documented. However, the mechanisms that facilitate these effects are poorly understood. The purpose of this study is to investigate within-session effects of throwing overload and underload baseballs to provide mechanistic evidence for weighted baseball training methods. Twenty-six collegiate- and professional-level baseball pitchers aged 20–30 years (mean age 23.5 [2.7] y) participated in a biomechanical evaluation while pitching a series of leather weighted baseballs. A 1-way repeated-measures analysis of variance was used to evaluate the intrasubject effect of ball weight on a total of 15 kinematic, kinetic, and performance parameters. Ball weight significantly affected pitch velocity, maximum elbow flexion, maximum pelvis rotation velocity, maximum shoulder internal rotation velocity, maximum elbow extension velocity, and anterior trunk tilt at ball release. None of the measured arm joint kinetics were significantly affected by ball weight. Training with 3- to 7-ounce (85- to 198-g) baseballs can be used to work on increasing pitching velocity without increasing throwing arm joint kinetics. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study was to determine the effectiveness of a low volume anaerobic training session, electrical stimulation, cupping therapy, and sequential compression for decreasing blood lactate in collegiate pitchers after pitching. Methods: 20 healthy collegiate baseball pitchers consented to participate in this study as a convenience sample (age 21.6 ± 1.90 years; height 175.61 ± 21.41 cm; mass 80.33 ± 8.07 kg). A total of 17 participants completed the study. Subjects were randomly assigned to one of the four interventions and rotated between interventions in one-week increments. The interventions used were a low volume anaerobic training session, electrical stimulation, cupping therapy, and sequential compression. The a low volume anaerobic training session, electrical stimulation, cupping therapy, and sequential compression for decreasing blood lactate in collegiate pitchers after pitching was assessed using a factorial repeated measures ANOVA (with two within-subject factors: treatment and time of measurement). The assumption for sphericity was examined based on Mauchly's test, and where the assumption was violated ANOVA output was assessed based on Greenhouse-Geisse's correction (For epsilon <=0.75) or Huynh-Feldt's correction (for epsilon>0.75). Post-hoc pairwise analyses with Bonferroni corrections were performed for statistically significant findings, with all assessments based on the 5% significance level. Results: While blood lactate levels increased with a low volume anaerobic training session (mean difference = 0.7120 p=0.57), there were statistically significant decreases immediately after the intervention for sequential (mean difference =-2.64, p=0.03) and cupping therapy (mean difference =--2.94, p<0.001). While there was a decrease in blood lactate levels following electrical stimulation, this decrease was not statistically significant (mean difference =-0.712, p=0.26). Conclusion: Blood lactate levels decreased in the period immediately following pitching with the use of cupping and sequential compression. These benefits were not seen with a low volume anaerobic training session and electrical stimulation. [ABSTRACT FROM AUTHOR]

Background: The impact of single-sport specialization on performance and injury risk in youth and adolescent athletes remains debated. The purpose of this study was to determine the incidence of single-sport specialization and its association with pitch velocity, pitcher utilization, range of motion, strength, and injury history. Methods: High school pitchers in the Northeastern, Southeastern, Midwestern, and Western Regions of the United States were prospectively recruited. Prior to the season, pitchers were surveyed about their basic demographics, sport participation history, and injury history. At this timepoint, a standardized physical examination was performed and max pitch velocity was measured. They were then prospectively followed over the ensuing high school season, where pitch utilization and counts were followed and injuries were tracked. Results: Across the study, 115 pitchers were recruited, of whom 53% played baseball as their only sport and 47% played other sports. Single- position specialization within baseball was uncommon as 90% of athletes played positions other than pitcher. There were no differences in range of motion, strength, or pitch velocity between multisport athletes and single-sport specialists. Within the multisport group, 26% reported a history of injury, while 38% of the single-sport specialists reported a history of injury (P = .179). There were no significant differences in pitcher utilization between multisport athletes and single-sport specialists. Only a single prospective injury occurred in the 115 players. Conclusion: Although single-sport specialization is common, nearly half of all high school pitchers in this study were multisport athletes. While injury history was generally similar between the two groups, single-sport baseball players did not have the following: improved motion, increased strength, higher ball velocity, or greater pitching volumes during the high school baseball season compared to multisport athletes. Accordingly, single-sport specialization did not have a competitive advantage for these high school pitchers based on the performance factors studied. Further prospective studies are necessary to understand the association between single-sport specialization and injury risk in high school baseball players.

Context: Fatigue of the shoulder rotators may cause reduction of the subacromial space (SAS) and contribute to rotator cuff tendinopathy. Objectives: To compare the isokinetic peak torques and fatigue ratios of shoulder external rotators (ER) and internal rotators (IR) between elite softball athletes with and without rotator cuff tendinopathy and to investigate their associations with the SAS. Design: Cross-sectional study. Setting: University laboratory. Participants: Twenty-five elite softball players and 31 asymptomatic sedentary controls participated in this study. Main Outcome Measures: Isokinetic concentric IR and ER peak torque and fatigue ratio were measured at 60°/s and at 180°/s, respectively; and ultrasound measurement of the SAS was measured during 0° and 60° of shoulder abduction. Results: Athletes with rotator cuff tendinopathy demonstrated lower peak torque in shoulder concentric ER when compared with their healthy counterparts (37.8 [5.8%] vs 43.6 [8.5%]). No significant difference was found in the fatigue ratios of ER, IR, and ER/IR when compared between elite softball athletes with and without rotator cuff tendinopathy (all P >.24). In asymptomatic athletes, greater IR peak torque (r =.583, P =.03), lower ER/IR strength ratio (r = −.605, P =.02), and greater ER/IR fatigue ratio (r =.575, P =.03) were moderately associated with more reduction of the SAS during 0° and 60° of shoulder abduction. Conclusions: Decreased strength ratio and fatigue ratio of ER/IR were related to reduction of the SAS. [ABSTRACT FROM AUTHOR]

Background: Although pitch count and rest guidelines have been promoted for youth and adolescent baseball players for nearly 2 decades, compliance with guidelines remains poorly understood. Purpose/Hypothesis: The purpose of this study was to determine the frequency of compliance with Major League Baseball (MLB) Pitch Smart guidelines as well as the association between compliance and range of motion (ROM), strength, velocity, injury, and pitcher utilization. It was hypothesized that pitchers in violation of current recommendations would have increased strength, velocity, and injury. Study Design: Case-control study; Level of evidence, 3. Methods: This was a prospective, multicenter study of 115 high school pitchers throughout the United States. Pitchers were surveyed about their compliance with current off-season, rest-related guidelines, and history of injury. During the preseason, pitchers underwent standardized physical examinations, and pitch velocity was measured. Pitch counts were collected during the baseball season that followed. Dynamometer strength testing of shoulder forward flexion, and external rotation as well as grip strength was recorded. We compared pitchers who were compliant with recommendations with those who were noncompliant using Student t and Mann-Whitney U tests. Results: Based on preseason data, 84% of pitchers had violated current Pitch Smart guidelines. During the season, 14% had at least 1 violation of the Pitch Smart guidelines. Across both the preseason survey and in-season pitch counts, 89% of players had at least 1 violation of the Pitch Smart guidelines. While there were no significant differences in ROM or strength, the noncompliant group had higher maximum pitch velocity than the compliant group (74 ± 8 vs 69 ± 5 mph [119 ± 13 vs 111 ± 8 kph], respectively; P =.009). Players' self-reported velocity differed significantly from the direct measurement, for both peak velocity (80 ± 6 vs 73 ± 8 mph [129 ± 9 vs 117 ± 13 kph], respectively; P <.001) and mean velocity (73 ± 8 vs 53 ± 27 mph [117 ± 13 vs 85 ± 43 kph], respectively; P <.001). Conclusion: Most high school pitchers were not fully compliant with current Pitch Smart guidelines, and they tended to overestimate their peak velocity by 7 mph (11 kph). Pitchers who threw with greater velocity were at higher risk for violating Pitch Smart recommendations. [ABSTRACT FROM AUTHOR]

Context: Hip abductor musculature contributes to the stability of the pelvis, which is needed for efficient energy transfer from the lower-extremity to the upper-extremity during overhead throwing. Objective: The purpose of this study was to examine the effects of a bilateral hip abduction fatigue protocol on overhead-throwing kinematics and passive hip range of motion. Design: Prospective cohort study. Setting: Controlled laboratory setting. Participants: A convenience sample of 19 collegiate female softball players (20.6 [1.9] y; 169.3 [9.7] cm; 73.2 [11.2] kg). Main Outcome Measures: Repeated hip abduction to fatigue was performed on an isokinetic dynamometer for 3 consecutive days. Trunk and shoulder kinematics during throwing and hip internal and external rotation range of motion were analyzed prior to fatigue on day 1 (prefatigue) and following fatigue on day 3 (postfatigue). Results: Repeated-measures analysis of variances revealed no statistically significant differences in trunk and shoulder kinematics prefatigue and postfatigue. A statistically significant time × side × direction interaction (F2,36 = 5.462, P =.02, η p 2 =.233) was observed in hip passive range of motion. A decrease in throwing-side hip internal rotation prefatigue to postfatigue (mean difference = −2.284; 95% confidence interval, −4.302 to −0.266; P =.03) was observed. Conclusions: The hip abductor fatigue protocol used in this study did not significantly alter trunk and upper-extremity throwing kinematics. The lack of changes may indicate that fatigue of the hip abductors does not contribute to trunk and shoulder kinematics during throwing or the protocol may not have been sport-specific enough to alter kinematics. [ABSTRACT FROM AUTHOR]

Background: Emerging evidence suggests that the long head of the biceps (LHBT) may play a role in stabilizing the glenohumeral joint, and this has led to controversy around the efficacy of biceps tenotomy for superior labral anterior and posterior (SLAP) lesions. Therefore, the aim of this finite element analysis (FEA) study was to determine the stress absorption and humeral head translation restriction effects of the LHBT within the glenohumeral joint during the late cocking and deceleration phases of overhead throwing with a view to resolving the controversy around tenotomy., Methods: Eight FEA models were created using computed tomography and magnetic resonance imaging data from normal glenohumeral joints. The models represented 4 LHBT conditions: uninjured, subpectoral tenodesis, tenotomy, and type II SLAP lesions. The late cocking and deceleration phases of the overhead throwing were simulated for each model. The impacts of the 4 LHBT conditions on glenohumeral joint stress absorption and humeral head displacement restriction were studied based on 1) stress and related distributions on the cartilage, labrum, capsule, and LHBT; and 2) humeral head translation variation., Results: The FEA analysis showed that the magnitude of the contact stress on the articular cartilage, labrum, and capsule was the lowest in the uninjured models, followed by the subpectoral tenodesis, tenotomy, and type II SLAP lesion models. Humeral head translation was the most restricted in the subpectoral tenodesis models, followed by the tenotomy and type II SLAP lesion models., Conclusion: FEA demonstrated that the LHBT plays a significant role in stress absorption and displacement restriction in the late cocking and deceleration phases of overhead throwing. Subpectoral tenodesis of the LHBT exhibited lesser amount of stress and humeral head translation than those of tenotomy, thereby making it a better option for patients who engage in overhead throwing., (Copyright © 2024 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.)

Background: The ulnar collateral ligament (UCL) is frequently injured in overhead throwing athletes, leading to elbow instability, pain and decreased performance, and requiring surgical intervention. Augmenting with suture tape provides a novel approach to UCL repair, offering stability while preserving native anatomy, proprioception, and minimizing bone loss, with the added benefit of an expected faster rehabilitation and return to sport (RTS) compared to traditional UCL reconstruction. The purpose of this study is to assess the variability of the current publicly available rehabilitation protocols for elbow UCL repair with suture tape augmentation., Methods: A systematic review of Google and PubMed was performed to find rehabilitation protocols for UCL repair with suture tape augmentation. Two hundred nine orthopedic surgery residency programs were identified using the Fellowship and Residency Electronic Interactive Database Access. The programs were searched on Google, a broad nonspecific Google search, and a systematic literature search of journal databases for UCL repair with suture tape augmentation rehabilitation protocols was conducted., Results: Thirteen rehabilitation protocols met the inclusion criteria for analysis. Of these, 12 protocols outlined the use of an articulating brace at varying range of motion settings for the first 4-6 weeks following surgery. Return to throwing was included in all 13 protocols and began between 10 and 12 weeks following surgery. RTS was included in 11 protocols and expected athletes competing as early as 16 weeks with a mean recommended RTS at 21.5 weeks., Conclusion: Rehabilitation protocols for UCL repair with suture tape augmentation were often structured around a 5-phase program with RTS approaching 20 weeks. They utilized immobilization and range of motion restriction as well as strengthening and gradual RTS procedures. Overall, the included protocols had mild variability with initiation of throwing and RTS 12 to 24 weeks faster than traditional UCL reconstruction., (© 2024 The Authors.)

The present study investigated the differences in the stride pattern of the lower extremities among different stride types in baseball pitchers with the aim of evaluating stride movement and skills to improve training effectiveness. Thirty elite male college baseball pitchers volunteered to pitch on an indoor-mound-like force plate, where motion data of their fastest strike trials were collected using an eight-camera motion analysis system at a 200–250 Hz sampling rate. Pelvis center trajectories of each participant were calculated and further categorized into three groups: tall-and-fall (TF), dip-and-drive (DD), and mixed (MX) pitchers. Motion analysis revealed that DD pitchers initiated pivot–knee extension and pivot–hip adduction earlier than TF pitchers and accelerated their bodies sooner than TF pitchers. In addition, TF pitchers accelerated their bodies forward by pivoting their legs until the middle of the arm-cocking and acceleration phases. The movement patterns of MX pitchers were similar to those of DD pitchers in terms of pivot leg, although this occurred a little later in the stride. Our findings are useful in developing training strategies for coaches, players, and trainers to better meet the demands of different pitching styles.

The ulnar collateral ligament is commonly injured in overhead-throwing athletes, particularly baseball pitchers. Pitch movement (break) is a critical aspect to pitching performance. The primary purpose of this study was to determine the changes in pitch velocity, pitch break, angle of break, and pitch performance metrics before and after ulnar collateral ligament reconstruction (UCLR) in Major League Baseball (MLB) pitchers. The secondary purpose was to determine changes in pitch performance metrics before and after UCLR. We hypothesized that pitch break and pitch performance metrics would be unchanged following UCLR. This was a retrospective case-series study of pitchers who had undergone primary UCLR between 2008 and 2014. Velocity, horizontal movement (Hmov), and vertical movement (Vmov) of each pitch were collected from the PITCHf/x system for each pitcher 12-24 months before surgery, 12-24 months after surgery, and 24-36 months after surgery. Overall break was calculated by taking the Pythagorean sum of Hmov and Vmov. Angle of break was determined by taking the inverse tangent of Vmov divided by Hmov. Repeated-measures analysis of covariance was performed to determine differences in pitch velocity, movement, angle of movement, and performance metrics between preoperative and postoperative time frames. Performance metrics included balls, strikes, swings, fouls, swings and misses, ground balls, line drives, pop-ups, fly balls, and home runs. Covariates included age at surgery, time from MLB debut to surgery, innings pitched as a starter, innings pitched as a reliever, and total pitches thrown. In a cohort of 46 pitchers who underwent UCLR between 2008 and 2014, pitch velocity, movement, and angle were not significantly changed with respect to preoperative or postoperative time frames. In addition, postoperative time frames had clinically insignificant differences in pitch performance metrics. Pitch break and performance metrics are not significantly affected in pitchers who return after UCLR. [ABSTRACT FROM AUTHOR]

Background: Few specific risk factors are known for shoulder injury in professional pitchers. New pitch-tracking data allow for risk stratification based on advanced metrics. Purpose/Hypothesis: The purpose of this study was to determine the association between shoulder injury, pitch frequency, and pitch metrics (velocity, total break, break angle, and spin rate) for the 4-seam fastball, curveball, and slider. We hypothesized that more frequent use of the 4-seam fastball would be associated with shoulder injury. Study Design: Case-control study; Level of evidence, 3. Methods: The Major League Baseball (MLB) database was queried for pitchers who had been placed on the injury list (IL) with a shoulder injury between 2015 and 2019. Injured pitchers were matched 1:1 with controls (pitchers not on the IL with a shoulder injury during the study period), based on age (±1 year), history of ulnar collateral ligament reconstruction, position (starter vs reliever), and pitches thrown during the injury season (±500). Pitch frequency, velocity, horizontal break, vertical break, total break, and spin rate for the season were collected from the Baseball Savant website for the 4-seam fastball, curveball, and slider. Univariate analysis was used to determine group differences for individual variables. Multiple logistic regression was performed to determine odds ratios (ORs) for shoulder injury associated with pitch frequency, velocity, total break, break angle, and spin rate. Covariates included age, position, ulnar collateral ligament reconstruction status, expected weighted on-base average, and total pitches thrown. Results: Overall, 233 injured pitchers were evaluated. The most common reason for IL placement was inflammation (78/233; 33.5%) followed by strain or sprain (61/233; 26.2%). Increased total pitch break was associated with an increased risk of shoulder injury for the 4-seam fastball (OR, 1.340 [95% confidence interval (CI), 1.199-1.509]; P <.001) and slider (OR, 1.360 [95% CI, 1.206-1.554]; P <.001). For the slider, a decreased spin rate (OR = 0.998 [95% CI, 0.997-0.999]; P =.026) and a more vertical break angle (OR = 1.170 [95% CI: 1.073-1.278]; P =.004) were associated with increased risk of injury. Conclusion: Increased pitch break of the 4-seam fastball and slider was associated positively with shoulder injury in MLB pitchers. These findings add to the understanding of throwing injury and ability to detect risk using ball-tracking technology. [ABSTRACT FROM AUTHOR]

Background Repetitive pitching places tremendous forces on the shoulder and elbow which can lead to upper extremity (UE) or lower extremity (LE) overuse injuries. Purpose The purpose of this study was to evaluate pre-season physical measurements in collegiate baseball players and track in-season baseball throwing volume to determine which factors may predict throwing overuse injuries. Study Design Retrospective Cohort study. Methods Baseline preseason mobility, strength, endurance, and perception of function were measured in 17 collegiate baseball pitchers. Participants were then followed during the course of the season to collect rate of individual exposure, estimated pitch volume, and rating of perceived exertion in order to determine if changes in workload contributed to risk of injury using an Acute-to-Chronic Workload ratio (ACWR). Results Participants developing an injury had greater shoulder internal rotator strength (p=0.04) and grip strength in a neutral position (p=0.03). A significant relationship was identified between ACWR and UE injuries (p <0.001). Athletes with an ACWR above or below 33% were 8.3 (CI95 1.8-54.1) times more likely to suffer a throwing overuse injury occurring to the upper or lower extremity in the subsequent week. Conclusion ACWR change in a positive or negative direction by 33% was the primary predictor of subsequent injury. This finding may assist sports medicine clinicians by using this threshold when tracking pitch volume to ensure a safe progression in workload during a baseball season to reduce the risk of sustaining overuse upper or lower extremity injuries. [ABSTRACT FROM AUTHOR]

Though chronic overhand throwing is known to result in range of motion and strength adaptations, there is limited research regarding interventions for maintenance of these characteristics. Therefore, the purposes of this study were to explore the use of a pre-throwing protocol focusing on lumbopelvic-hip complex musculature in high school baseball players and examine its effects on shoulder and hip range of motion and isometric strength over the course of a season. Four exercises were added to the intervention team's warm-up routine. The control and intervention teams' passive bilateral hip and shoulder range of motion and isometric strength were assessed pre/post-season. A multivariate analysis of variance revealed significant differences in delta scores between the teams for multiple shoulder and hip range of motion and isometric strength variables. Key results were the intervention team lost significantly more stride hip external rotation but gained more isometric strength than the control team. The intervention team was also able to better maintain shoulder range of motion than the control team. Practitioners should use the results of this study and consider incorporating exercises that target lumbopelvic-hip complex musculature into their current training program. [ABSTRACT FROM AUTHOR]

This study aimed to describe stationary overhead throwing biomechanics in South African cricketers, considering playing level, and relative to baseball. Kinematics and ground reaction forces were collected during throwing trials. Inverse dynamics was used to calculate joint kinetics. Inter-subject variability was calculated using the coefficient of variance. A one-dimensional statistical parametric mapping ANOVA was conducted to assess differences between the kinematic waveforms in elite and amateur cricketers (p < 0.05). Fifteen cricketers (elite = 8; amateur = 7) participated in this study. The basic parameters of a cricketer's throwing action are described. Substantial inter-subject variability was noted for all variables, except lumbopelvic movement. Cricketers presented with 74.9 ± 27.3° glenohumeral external rotation and 94.8 ± 23.7° elbow flexion, at maximum external rotation (MER). Amateur cricketers displayed decreased elbow flexion range of motion between 2-14% of the throwing cycle (F = 9.365;p = 0.01); greater shoulder (121.0vs85.9 N; F = 0.36,p = 0.021) and elbow compression (105.6vs72.8 N;F = 0.007,p = 0.043), and superior shoulder force (203.1vs115.5 N;F = 2.43,p = 0.022) at MER, when compared with elite cricketers. Cricketers display similarities to baseball pitchers when throwing overhead from a stationary position. The "preparatory arc" utilised is different to the wind-up noted for baseball. The forces exerted on the shoulder and elbow, in amateur cricketers specifically, are substantially greater at MER and may indicate the potential risk for injury. [ABSTRACT FROM AUTHOR]

The purpose of this study was to assess single-leg squat (SLS) performance on reported pain. Forty-two youth softball athletes (13.0 ± 2.0 years; 162.19 ± 9.75 cm; 60.80 ± 14.28 kg) completed a bilateral SLS and a health history questionnaire in which they indicated if they were currently experiencing any pain/discomfort. Due to the clinical significance of the current study, p < 0.10 was classified as nearing significance. A point-biserial correlation was run between the groups (pain and no pain) and all kinematic variables (maximal knee flexion, knee valgus/varus, vertical sacrum displacement, anterior pelvic tilt, and pelvic lateral tilt) at each event (45° descent, maximal knee flexion, and 45° ascent), across each phase (descent, ascent), and between legs. Increased vertical sacrum displacement was correlated with pain at 45° ascent and at maximal knee flexion in the right SLS. Knee valgus at maximal knee flexion, 45° ascent, and in the decent phase of the left SLS was significant. Anterior pelvic tilt in the decent phase of the left SLS and knee valgus and pelvic lateral tilt in the decent phase of the right SLS were found to be significantly correlated with pain. Poor SLS performance was correlated with reported pain. [ABSTRACT FROM AUTHOR]

The pitching motion is an asymmetric action by which coordination of scapular rotation in the dominant arm might be affected in time and in comparison with the non-dominant arm. The study aimed to compare asymmetry and the evolution of scapular upward rotation over a one-year period. Data were collected twice, before and after a one-year period, from 92 participants (age = 15.1 SD 1.4 years, body height = 177.3 SD 10.9 cm, body weight 69.2 SD 14.5 kg). Scapular motion was tracked at different glenohumeral angles of elevation in the scapular plane: anatomical position (0°), 45°, 90° and 135°. Scapular upward rotation was calculated as the angle between the spinae scapula and the spine. Scapular upward rotation of the dominant arm was 5.1° (95% CI: 2.1°−8.1°) more compared to the non-dominant arm. Age group or glenohumeral angles of elevation did not affect this difference. Scapular upward rotation of the dominant arm decreased 1.9° (95% CI: −0.5° to 4.3°) after a one-year period, however, neither this observation, nor the interaction with age group or elevation angle was significant. These findings may indicate that pitchers could be at risk to develop shoulder injuries especially those that have been associated with scapular asymmetry.

Context: Previous research has indicated that throwing sports expose athletes to overuse injuries and that specialization in sport is linked to injury. However, the effect of overexposure to a throwing sport on a dynamic movement task is unknown. Objective: To determine if sport specialization in youth throwing athletes affected performance on the single-legged squat (SLS). Design: Descriptive laboratory study. Setting: University research laboratory. Patients Or Other Participants: A total of 49 youth baseball and softball athletes (23 baseball, 26 softball; age = 12.96 ± 2.32 years, height = 165.01 ± 13.05 cm, mass = 61.42 ± 13.04 kg) were recruited. Main Outcome Measure(S): Participants were grouped into 3 categories based on specialization definitions: (1) 8 months or longer in season, (2) 8 months or longer in training, or (3) 8 months or longer in season and previously quit another sport. We measured SLS kinematics and used a set of 1-way multivariate analyses of variances to determine if trunk kinematics differed by group. Results: Athletes who spent 8 months or more in sport-specific training exhibited significantly more trunk control, revealed by less trunk lateral flexion (Λ = 0.69, F6,38 = 2.89, P = .020) and less trunk flexion (Λ = 0.69, F6,38 = 2.88, P = .021) throughout an SLS. Conclusions: These results agree with the principle of specific adaptation to imposed demands. Surprisingly, athletes who spent 8 months or more playing a unilateral sport showed no differences in SLS performance. Clinicians should emphasize that neuromuscular adaptations of the lumbopelvic-hip complex for dynamic movement, such as an SLS, may be achieved through training instead of strict sport participation. Future researchers should consider how much of the training protocol is actually specialized for sport training. [ABSTRACT FROM AUTHOR]

Background: Excessive baseball pitch volume has been associated with increased risk of injury in adolescents. However, many collegiate athletes report non-time loss injuries over the course of the season. It is unknown how pitch volume throughout a collegiate baseball season affects arm soreness. Purpose: The primary purpose of this study was to determine the relationship between pitch volume and selfreported arm soreness. A secondary purpose was to determine the relationship between change in pitch volume and change in arm soreness over the course of the season for collegiate baseball pitchers. Study Design: Prospective Cohort Methods: Seven collegiate baseball pitchers volunteered to participate in a yearlong prospective study. The seven pitchers reported daily pitch volume and level of soreness from the fall through spring collegiate baseball season during practices and games. The athletic trainer, a member of the research team, tracked athletic exposures and injuries for the entire season. Frequency counts of athletic exposures were categorized by game, practice, conditioning and injury status. Frequency counts of pitch volume was categorized by game, game bullpen, practice bullpen, flat ground, long toss and warm-up pitches. The pitch volume and soreness levels for each athlete were used to determine the relationship between these two variables using a Pearson correlation. Results: The seven pitchers were involved with 1,256 athletic exposures and a total of 54,151 throws, averaging 7,735 throws per player for the entire season. The pitch volume and self-reported arm soreness for the entire season revealed a correlation of r = .72 (p = .004). The relationship between change in pitch volume and change in arm soreness was r = .635 (p = .001) over the season. Conclusion: There was a moderate significant correlation between arm soreness and pitch volume across the whole season. This relationship was maintained when evaluating weekly changes. Level of Evidence: 4 [ABSTRACT FROM AUTHOR]

The purpose of this study was to assess single-leg squat (SLS) performance on reported pain. Forty-two youth softball athletes (13.0 ± 2.0 years; 162.19 ± 9.75 cm; 60.80 ± 14.28 kg) completed a bilateral SLS and a health history questionnaire in which they indicated if they were currently experiencing any pain/discomfort. Due to the clinical significance of the current study, p < 0.10 was classified as nearing significance. A point-biserial correlation was run between the groups (pain and no pain) and all kinematic variables (maximal knee flexion, knee valgus/varus, vertical sacrum displacement, anterior pelvic tilt, and pelvic lateral tilt) at each event (45° descent, maximal knee flexion, and 45° ascent), across each phase (descent, ascent), and between legs. Increased vertical sacrum displacement was correlated with pain at 45° ascent and at maximal knee flexion in the right SLS. Knee valgus at maximal knee flexion, 45° ascent, and in the decent phase of the left SLS was significant. Anterior pelvic tilt in the decent phase of the left SLS and knee valgus and pelvic lateral tilt in the decent phase of the right SLS were found to be significantly correlated with pain. Poor SLS performance was correlated with reported pain.

The pitching motion is an asymmetric action by which coordination of scapular rotation in the dominant arm might be affected in time and in comparison with the non-dominant arm. The study aimed to compare asymmetry and the evolution of scapular upward rotation over a one-year period. Data were collected twice, before and after a one-year period, from 92 participants (age = 15.1 SD 1.4 years, body height = 177.3 SD 10.9 cm, body weight 69.2 SD 14.5 kg). Scapular motion was tracked at different glenohumeral angles of elevation in the scapular plane: anatomical position (0°), 45°, 90° and 135°. Scapular upward rotation was calculated as the angle between the spinae scapula and the spine. Scapular upward rotation of the dominant arm was 5.1° (95% CI: 2.1°−8.1°) more compared to the non-dominant arm. Age group or glenohumeral angles of elevation did not affect this difference. Scapular upward rotation of the dominant arm decreased 1.9° (95% CI: −0.5° to 4.3°) after a one-year period, however, neither this observation, nor the interaction with age group or elevation angle was significant. These findings may indicate that pitchers could be at risk to develop shoulder injuries especially those that have been associated with scapular asymmetry. [ABSTRACT FROM AUTHOR]

Morphological differences between the Neandertal and modern human glenoid fossa are mostly attributed to functional factors. However, the intimate relationship between the pectoral girdle and the shape of the thorax on which it rests calls for a structural analysis of the morphology of the glenoid fossa. Using both 3D Geometric Morphometric techniques and classical osteometry we carry out an analysis of the morphology of Neandertal scapular glenoid fossa, considering the effects that independent parameters such as allometry, sexual dimorphism and laterality could exert on the glenoid fossa shape. We also discuss how the morphological configuration of the thorax together with other functional factors could explain some of the differences between Neandertals and H. sapiens , and we assess the morphological evolution of this structure in the context of the genus Homo . To this end, 3DGM methods were applied in a comparative framework including the new SD-2101 + specimen from the Sidrón site (Spain) dated to 49,000 years ago, other Neandertal, Homo sapiens , KNM-WT 15000 (Homo ergaster/erectus ) and Pan troglodytes specimens. A total of 75 sliding semilandmarks were used to collect the morphology of the glenoid fossa. Morphological comparison and variability were assessed through principal component analysis. Our results confirm the metric and morphological features of the Neandertal scapular glenoid fossa and point to a multifactorial effect in the glenoid morphology. We also detect a morphological trait of the Neandertal glenoid fossa that has not been reported previously: the projection of the upper part of the ventral border shared with modern humans and influenced by structural factors related to the configuration of the rib cage and shoulder. These results are consistent with the evolutionary framework of the hominin glenoid fossa, with some morphological changes being caused by functional factors, and others by structural factors such as the configuration of the thorax. [ABSTRACT FROM AUTHOR]

During an overhead throw, the gluteal muscle group stabilizes the lumbopelvic-hip complex (LPHC), leading to efficient energy transfer from the lower to upper extremity. It has been shown that LPHC instability can lead to throwing pathomechanics. The single leg squat has become a common assessment for LPHC stability, and could be used to determine the effects of fatigue on throwing athletes. The purpose of this study was to determine the effects of an acute abduction fatigue protocol on the LPHC of collegiate softball players via the single leg squat assessment of the leg ipsilateral to the throwing arm. Eighteen National Collegiate Athletic Association Division I sof tball players volunteered (20.5 ± 1.9 years; 169.4 ± 10.0 cm; 72.9 ± 11.5 kg). Each participant performed a single leg squat on the leg ipsilateral to the throwing arm prior to and post side-lying hip abduction fatigue. LPHC and lower extremity kinematics were examined to determine potential effects of fatigue on LPHC stability. There were no significant main effects or interactions of LPHC or lower extremity kinematics during the single leg squat assessments across the fatigue protocol. Based on the current study, an acute bout of fatigue to the hip abductors does not affect LPHC stability in single leg squat execution. [ABSTRACT FROM AUTHOR]

Background/Objectives: The purpose of this study was to examine the correlation of ball velocity with body variables in eight amateur baseball pitchers. Methods/Statistical analysis: Eight amateur baseball pitchers (over-arm pitchers) participated in the study. Body variables were measured using wearable gyro sensors while they were fastball pitching. MVN system can measure kinematic of whole body using inertial sensor. The velocity of the ball was measured using a speed gun. The Pearson correlation coefficient was used to analyze the correlation between pitch velocity and body variables. Significance levels were set at p<0.05. Findings: Ball velocity significantly correlated with the horizontal abduction and abduction of shoulder, trunk rotation angular velocity, stride length (p<0.05). However, no significant correlations were observed in trunk rotation angle (anterior and posterior), foot direction (p>0.05). Greater shoulder horizontal abduction during pitching motion has effective pre-stretch, stored elastic energy and tendons may be utilized during arm cocking and arm acceleration phase of pitch. As increased trunk rotation angular velocity, levels of trunks action develop more advanced and led to increases in energy transfer to the pitching arm. For stride length, it is regarded a not only critical kinematic factor for determine the timing of kinetic chain events but also transitioning energy to the pitching arm from lower extremity. In this study, we can compare with previous studies on pitching motion kinematics. Also previous studies on pitching motion analysis were mainly 3D camera based techniques. In this study, it is meaningful to analyze the pitching motion by using Gyro sensor which complements the limitation that 3D camera technique can have. Improvements/Applications: Horizontal abduction and abduction of shoulder, trunk rotation angular velocity and stride length should be considered to increase the ball velocity, which is an important ability of the pitcher. [ABSTRACT FROM AUTHOR]

In this cross-sectional study, the qualitative and quantitative throwing performance of male and female athletes (6 to 16 years of age) was analyzed. The goal of this study was to assess whether there were gender based qualitative and quantitative differences in throwing performance of young athletes, throughout three different age bands (childhood, pubescence, and adolescence). Furthermore, we explored whether all components of the throwing movement are equally affected by gender differences. Focus was placed on five essential components of action: trunk, forearm, humerus, stepping, and backswing. Therefore, children and adolescents (N = 96) were invited to throw three times from three different distances, while aiming at a target placed at shoulder height. The participants were aspiring athletes, competitive in the sport handball. For analyzing the quality of movement the component approach of Halverson and Roberton (1984) was used. The throwing accuracy was noted and used to evaluate the quantitative performance of the throwing movement. Throughout three different age bands, no statistically significant difference was found between genders in throwing accuracy, i.e., quantitative performance. Regarding the qualitative evaluation of the throwing movement, male and female athletes differed significantly. The component approach yielded higher scores for male than for female participants. As expected, with increasing age qualitative and quantitative performance of male and female athletes improved. These results suggest that there are gender-specific differences in qualitative throwing performance, but not necessarily in quantitative throwing performance. Exploration shows that differences in the qualitative throwing performance were seen in specific components of action. Male and female athletes demonstrated similar movement patterns in humerus and forearm actions, but differed in trunk, stepping, and backswing actions. [ABSTRACT FROM AUTHOR]

Background: The impact of single-sport specialization on performance and injury risk in youth and adolescent athletes remains debated. The purpose of this study was to determine the incidence of single-sport specialization and its association with pitch velocity, pitcher utilization, range of motion, strength, and injury history., Methods: High school pitchers in the Northeastern, Southeastern, Midwestern, and Western Regions of the United States were prospectively recruited. Prior to the season, pitchers were surveyed about their basic demographics, sport participation history, and injury history. At this timepoint, a standardized physical examination was performed and max pitch velocity was measured. They were then prospectively followed over the ensuing high school season, where pitch utilization and counts were followed and injuries were tracked., Results: Across the study, 115 pitchers were recruited, of whom 53% played baseball as their only sport and 47% played other sports. Single- position specialization within baseball was uncommon as 90% of athletes played positions other than pitcher. There were no differences in range of motion, strength, or pitch velocity between multisport athletes and single-sport specialists. Within the multisport group, 26% reported a history of injury, while 38% of the single-sport specialists reported a history of injury ( P  = .179). There were no significant differences in pitcher utilization between multisport athletes and single-sport specialists. Only a single prospective injury occurred in the 115 players., Conclusion: Although single-sport specialization is common, nearly half of all high school pitchers in this study were multisport athletes. While injury history was generally similar between the two groups, single-sport baseball players did not have the following: improved motion, increased strength, higher ball velocity, or greater pitching volumes during the high school baseball season compared to multisport athletes. Accordingly, single-sport specialization did not have a competitive advantage for these high school pitchers based on the performance factors studied. Further prospective studies are necessary to understand the association between single-sport specialization and injury risk in high school baseball players., (© 2023 The Authors.)

Proper utilization of the kinetic chain allows for efficient kinetic energy transfer from the proximal segments to the distal segments. The aims of this study were to describe muscle activations in 4 kinetic chain prethrowing exercises and compare these muscle activations with 3 traditional resistance-band exercises. Twenty-six healthy college students (22.9 ± 3.4 years; 172.2 ± 8.6 cm; 74.2 ± 16.3 kg), regardless of gender, participated. Surface electromyographic data were recorded for selected pelvic and scapular musculature while subjects performed the exercises. The exercises included airplane (single-leg balance with weight-bearing hip flexed to 908 and non-weight-bearing hip extended) while performing alternating repetitions of external and internal shoulder rotation, lunge, Get Up, single-leg balance, and resistance band I, T, and Y. A repeated-measures analysis of variance, with a factor of exercise (8 different levels), was used. Post hoc analyses were used for each muscle to determine the statistically significant differences between exercises. The results reveal the greatest activation occurred during the 2 airplane exercises than all the other exercises. The results of this study help to establish surface electromyographic data for selected pelvis and scapula musculature during a series of kinetic chain and resistance-band exercises. Understanding the muscle activations during these exercises can assist clinicians and coaches in choosing the appropriate exercises to implement for individuals involved in dynamic shoulder movement. [ABSTRACT FROM AUTHOR]

Background Alteration of elbow range of motion (ROM) has been observed in baseball pitchers. This study aims to compare dominant elbow ROM between early-puberty, late-puberty, and young–adult pitchers. Methods We recruited 62 pitchers, consisting of 17 early-puberty (mean age 13.1 years old), 22 late-puberty (mean age 17.7 years old), and 23 young–adult players (mean age 19.4 years old). Dominant elbow ROMs was measured. One-way ANOVA was used to compare the differences in elbow ROM variables between 3 groups. Results Late-puberty pitchers exhibited a significantly lower elbow hyperextension and flexion than early-puberty or young–adult pitchers (P < .05). Valgus angle was significantly lower in young–adult (7.7°±5.5°) versus early-puberty (12.1°±2.3°) and late-puberty pitchers (13.0°±4.1°; P < .05). Young–adult pitchers had the largest forearm supination range (101.2°±18.1°), followed by early-puberty (82.5°±6.5°; P < .05) and late-puberty pitchers (70.6°±15.8°). Elbow flexion-hyperextension total range was smallest in late-puberty pitchers (130.3°±7.4°), followed by young–adult (142.6°±9.3°) and early-puberty pitchers (144.6°±8.3°; P < .05). Forearm pronation–supination total range was also smallest in late-puberty pitchers (142.0°±20.3°), followed by early-puberty (159.8°±9.5°) and young–adult pitchers (177.2°±20.8°; P < .05). Conclusions These results indicate that careful monitoring of the elbow and forearm range of motion should be undertaken in adolescent baseball pitchers to prevent and or minimize injury risk. [ABSTRACT FROM AUTHOR]

In order to decrease the amount of time that it takes the catcher to throw the ball, a catcher may chose to throw from the knees. Upper extremity kinematics may play a significant role in the kinetics about the elbow observed in catchers throwing from the knees. If relationships between kinematics and kinetics exist then the development of training and coaching instruction may help in reduced upper extremity injury risk. Twenty-two baseball and softball catchers (14.36±3.86years; 165.11±17.54cm; 65.67±20.60kg) volunteered. The catchers exhibited a less trunk rotation (5.6±16.2°), greater elbow flexion (87.9±21.4°) and decreased humeral elevation (71.1±12.3°) at the event of maximum shoulder external rotation as compared to what has previously reported in catchers. These variables are important, as they have previously been established as potential injury risk factors in pitchers, however it is not yet clear the role these variables play in catchers' risk of injury. A positive relationship between elbow varus torque during the deceleration phase and elbow flexion at MIR was observed (r=0.609; p=0.003). Throwing from the knees reduces a catcher's ability to utilize the proximal kinetic chain and this may help to explain why their kinematics and kinetics differ from what has previously been presented in the literature. [ABSTRACT FROM AUTHOR]

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