011 The relationship between tightness of the hip joint and shoulder/elbow injury in high school baseball pitchers – a prospective study

Background The mechanics of pitching are quite complex, so improper coordination of the kinetic chain from the lower extremity to the trunk results in an improper upper arm position and increased risk of shoulder/elbow injury. Several studies reported that upper extremity tightness are risk factors for shoulder and elbow injuries in high school baseball players, however, studies on the relationship between tightness of the lower extremities and shoulder and elbow pain in pitchers have been insufficient. Purpose The purpose of this study was to prospectively examine the relationships between hip ROM in the preseason and throwing-related shoulder/elbow injuries in the season in high school baseball pitchers. Design Prospective cohort study Methods The study included 125 high school baseball pitchers (median age 16.5 [15–17] years). The following physical parameters were assessed: (1) hip ROM (flexion, internal rotation [IR], external rotation [ER]) in the supine position, (2) hip ROM (IR, ER) in the prone position. After the season, the participants completed questionnaires regarding shoulder and/or elbow injuries, with injury defined as an inability to play for ≥1 week due to elbow/shoulder problems. The results of injured and non-injured patients were compared. Results Eleven throwing-related injuries (9%) were observed during the season. In the injured group, the ROM of the plant side hip with 90° flexed external rotation was significantly lower than that in the non-injured group (40.0°±8.2° and 48.3°±11.7°, respectively; P=0.02). There was no significant difference in the ROM of the plant side hip with 0°flexed external rotation. No significant differences were observed between the injured and non-injured groups with respect to hip ROM on the trail side. Conclusion A preseason decrease in the 90° flexed external rotation on the plant side was an independent risk factor for shoulder and elbow injuries in high school baseball pitchers.

Background Due to the large burden of injuries, injury prevention is utmost important in elite-level youth soccer.Targeting risk management strategies more efficiently, requires a better knowledge of injury risk.Objective To identify the injury risk in elite-level youth soccer players based on a large number of anthropometric and motor performance measures using a data science approach.Design Prospective cohort study.Setting Youth academies of seven Belgian premier league soccer clubs.
Participants 734 male players of the U10 to U15 age categories (mean age: 11.7±1.7 years).Assessment of risk factors Preseason anthropometric measurements (height, weight, and sitting height) and tests to assess physical fitness (strength, flexibility, speed, agility, and endurance) and motor coordination (Körperkoordinationstest für Kinder) were taken.Main outcome measurements Injuries were monitored continuously during one competitive season by the academies' medical staff.Machine learning, using extreme gradient boosting algorithms (XGBoost), was used to differentiate injured from noninjured players based on their baseline test results.Subsequently, the same technique was used to classify injuries as either overuse or acute.Results During the season, 609 injuries occurred in 368 players, sustaining 1 to 7 injuries each.Of these injuries, 290 were identified as overuse and 319 as acute injuries.The machine learning algorithm was able to classify the injured players with 92% precision, 92% recall and 92% accuracy.Injuries could be classified as overuse or acute with 95% precision, 94% recall and 94% accuracy.The features in the model were ranked according to their importance in the decision process.Conclusions Machine learning is a promising approach to assess injury risk based on anthropometric and motor performance measures in this population.This knowledge could be applied in injury risk management strategies, aiming at youth players with the highest risk and targeting those features that have the largest influence on injury risk.

PREVENTION OF SHOULDER AND ELBOW INJURIES IN HIGH SCHOOL BASEBALL PLAYERS: A TIME-TO-EVENT ANALYSIS
Background Decreased range of motion (ROM) and muscle weakness in the dominant shoulder are known as significant risk factors for shoulder and elbow injuries in high school baseball pitchers.However, there is no previous study investigating the outcomes of upper-body injury prevention programs for these risk factors.Objective We prospectively investigate if a prevention program to improve the risk factors reduces the incidences of shoulder and elbow injuries.Design Interventional study.Setting High school league.Participants Ninety-two male high school baseball pitchers participated.Exclusion criteria: (1) prior injury to the throwing arm, (2) unable to throw, or (3) performed daily muscle-specific rotator cuff training or posterior capsule/sleeper stretches.Interventions Participants were taught to perform stretching and strength exercises aimed at improving shoulder internal rotation ROM and external rotation strength in the preseason.The pitchers freely chose to participate in one of four groups [SM-group: performed both exercises, S-group: performed stretching exercise only, M-group: performed strength training alone, and N-group: performed neither intervention].Injury was defined as inability to play for ≧8 days because of shoulder/elbow symptoms.Main outcome measurements For a time-to-event analysisthe Kaplan-Meier survival curves were generated and hazard ratios (HRs) for injury occurrence were calculated using multivariate Cox regression.Log-rank tests were used for between-group comparisons of survival distributions.Results Injuries occurred in 25%, 35% and 57% of participants and median times to injury were 89, 92, and 29.5 days in the S (n=32), SM (n=46) and N (n=14) groups, respectively.Nobody chose the M group.HRs were 0.36 and 0.47 for the S and SM group, respectively, based on the N group as reference.The incidence of injury was significantly lower in the S group than in the N group (p=0.04).Conclusions Shoulder stretching significantly prevented baseball-related shoulder and elbow injures and significantly prolonged pitching availability during the season.

THE RELATIONSHIP BETWEEN TIGHTNESS OF THE HIP JOINT AND SHOULDER/ELBOW INJURY IN HIGH SCHOOL BASEBALL PITCHERS -A PROSPECTIVE STUDY
Noritaka Hamano*, Hitoshi Shitara, Tsuyoshi Ichinose, Tsuyoshi Sasaki, Kamiyama Masataka, Miyamoto Ryosuke, Fukui Kurume, Tsuyoshi Tajika, Takuro Kuboi, Fumitaka Endo, Kenji Takagishi, Hirotaka Chikuda.Department of Orthopaedic Surgery, Gunma University Graduate School of Medicine, Gunma, Japan 10.1136/bjsports-2020-IOCAbstracts.11 Background The mechanics of pitching are quite complex, so improper coordination of the kinetic chain from the lower extremity to the trunk results in an improper upper arm position and increased risk of shoulder/elbow injury.Several studies reported that upper extremity tightness are risk factors for shoulder and elbow injuries in high school baseball players, however, studies on the relationship between tightness of the lower extremities and shoulder and elbow pain in pitchers have been insufficient.Purpose The purpose of this study was to prospectively examine the relationships between hip ROM in the preseason and throwing-related shoulder/elbow injuries in the season in high school baseball pitchers.
Design Prospective cohort study Methods The study included 125 high school baseball pitchers (median age 16.5 [15-17] years).The following physical parameters were assessed: (1) hip ROM (flexion, internal rotation [IR], external rotation [ER]) in the supine position, (2) hip ROM (IR, ER) in the prone position.After the season, the participants completed questionnaires regarding shoulder and/or elbow injuries, with injury defined as an inability to play for !1 week due to elbow/shoulder problems.The results of injured and non-injured patients were compared.
Results Eleven throwing-related injuries (9%) were observed during the season.In the injured group, the ROM of the plant side hip with 90°flexed external rotation was significantly lower than that in the non-injured group (40.0°±8.2°and 48.3°±11.7°,respectively; P=0.02).There was no significant difference in the ROM of the plant side hip with 0°flexed external rotation.No significant differences were observed between the injured and non-injured groups with respect to hip ROM on the trail side.Conclusion A preseason decrease in the 90°flexed external rotation on the plant side was an independent risk factor for shoulder and elbow injuries in high school baseball pitchers.Background Although descriptions of injury inciting events are of key importance to understand the causes of any particular injury type, systematic analysis of inciting events remain rare.Objective Identification and description of recurrent injury patterns in professional football.Design Prospective video analysis of moderate and severe match injuries.Setting Two highest divisions in German professional male football (Bundesliga, 2. Bundesliga).Patients (or Participants) All players who played at least one competitive club match within the seasons 2014/15, 15/16 and 16/17 were included (n=1,449).Interventions (or assessment of risk factors) Systematic video analysis of all moderate and severe match injuries (timeloss ! 8 days) that were registered by clubs or physicians with the VBG (German statutory accident insurance for professional athletes) as part of the occupational accident reporting.Main outcome measurements An observation form was developed and evaluated containing five categories: (I) general match and player information, (II) localisation of the injury on the pitch, (III) game situation and player/opponent behaviour, (IV) injury mechanism and (V) injured body location.Results Of the 857 moderate and severe match injuries, 345 (40.3%) were clearly identified in the video footage and included to the analysis.Of these, almost half were contact injuries (49.3%), 23.2% non-contact injuries and the remaining 27.5% indirect-contact injuries.Most contact injuries were caused by collisions with the opponent (46.5%); non-contact injuries were commonly caused by structural overexertion (71.3%).Finally, nine recurrent comprehensive injury patterns were identified and described.Conclusions Future preventive approaches should prepare players for the identified recurrent injury situations to reduce injury burden in professional football.One of the main findings was that own tackles are football-specific actions with a high risk for injuries, particularly for knee injuries.Thus, player behaviour and technique skills might present areas with considerable preventive potential.The resulting video database can be used in coaching education to demonstrate recurrent match situations with a high risk for injuries.Background Athletic hip and groin pain is common in the Gaelic Athletic Association (GAA) but its prevalence at elite level is unknown.The changes in Hip and Groin Outcome Score (HAGOS) over a season in and the ability of HAGOS to identify those athletes who will go onto develop hip and groin symptoms has not been reported previously.

PREVALENCE OF HIP AND GROIN PAIN AND CHANGES IN HIP AND GROIN OUTCOME SCORE OVER A SEASON IN ELITE GAELIC ATHLETIC ASSOCIATION PLAYERS
Objective The aim of this study was to report the prevalence of hip and groin symptoms and the changes in HAGOS score across a season in elite GAA players and examine the relationship between pre-season HAGOS scores and self-reported groin pain during that season.Design Retrospective cohort study.Participants There were 1241 elite intercounty GAA players who participated at the start of the 2017 and 2018 seasons.Interventions (or assessment of risk factors) Online Questionnaire.Main outcome measurements The HAGOS questionnaire and self reported incidence of groin pain in previous season.Results There was a high prevalence of hip and groin pain reported in elite GAA athletes over the course of a season (36%).There was no change on average across all the HAGOS subscales apart from Physical Activity which had a medium effect size change (d=0.44) with 12 to 22% of athletes showing a decrease greater than minimal detectable change across HAGOS subscales over the course of a season and 15-34% showing an increase.There was poor ability to predict the incidence of hip and groin pain using pre-season HAGOS (AUC=0.57to 0.67).Conclusions There is a high prevalence of hip and groin pain in elite GAA athletes with group HAGOS masking individual changes across cohort.There is poor ability of pre-season HAGOS to predict incidence of hip and groin pain in elite GAA athletes in the subsequent season.