Junior High School Baseball Players Research Articles

Relationships between Physical Functions Involved in the 30-m Sprint and Standing Broad Jump in Junior High School Baseball Players

Relationships between Physical Functions Involved in the 30-m Sprint and Standing Broad Jump in Junior High School Baseball Players

The Relationship between Elbow Pain, Standing Up and Sitting On One Leg, Throwing Plane in Junior High School Baseball Players

The Relationship between Elbow Pain, Standing Up and Sitting On One Leg, Throwing Plane in Junior High School Baseball Players

Reciprocal inhibition improves posterior shoulder tightness and shoulder range of motion in youth baseball players.

BackgroundThe aim of this study was to evaluate the efficacy of reciprocal inhibition for posterior shoulder tightness (PST), internal rotation at 90° abduction (ABIR) limitation, and subacromial impingement in elementary and junior high school baseball players.MethodsThe present study included 290 elementary school and junior high school baseball players who were members of an organized baseball team and attended a medical checkup in 2014. Seventeen participants were excluded because they were left-handed. We applied a sit-up exercise as a tool of reciprocal inhibition to all participants. Before and after the sit-up exercise, we evaluated the shoulder range of motion (ROM) in external rotation at 90° abduction (ABER), ABIR, and horizontal flexion (HF) in both shoulders and the prevalence of subacromial impingement in the dominant shoulder. We defined PST as a ≧15°decrease in the HF angle of the dominant shoulder in comparison to the nondominant shoulder before the sit-up exercise and divided participants into two groups (the PST group and the non-PST groups). An independent t-test was performed to compare the shoulder ROM, and a chi-squared test was performed to compare the prevalence of subacromial impingement between the two groups. A dependent t-test was performed to compare intragroup changes in the shoulder ROM. The McNemar test was performed to compare intragroup changes in the prevalence of subacromial impingement.ResultsFifty-six of 273 participants had PST in the initial examination. The initial examination revealed that the ROM of ABIR and HF in the dominant shoulder were significantly lower in the PST group than those in the non-PST group, whereas the ROM of ABER and total arc were significantly higher in the PST group. The prevalence of subacromial impingement in the PST group was significantly higher than that in the non-PST group. The sit-up exercise improved ABER, ABIR, total arc, HF, and the prevalence of subacromial impingement in both groups. However, the amount of ROM change did not differ between the two groups for any parameter with the exception of HF.ConclusionThe presence of PST affects the prevalence of subacromial impingement but was not related to the loss of ABIR or the prevalence of pathological glenohumeral internal rotation deficit. The sit-up exercise, as reciprocal inhibition, can transiently improve the prevalence of subacromial impingement via the improvement of PST.

小・中学生野球選手における下肢・体幹理学所見と肘関節超音波異常所見との関連性―広島野球障害検診（HYMECS）に参加した小・中学生別での検討―

小・中学生野球選手における下肢・体幹理学所見と肘関節超音波異常所見との関連性―広島野球障害検診（HYMECS）に参加した小・中学生別での検討―

Relationship Between Upper Limb Injuries and Hip Range of Motion in Elementary and Junior High School Baseball Players.

Background:Shoulder and elbow injuries are major problems in baseball players. Tightness of the upper extremities has been reported as a risk factor for shoulder and elbow injuries in elementary and junior high school baseball players. However, few studies have been conducted on the relationship between decreased hip range of motion (ROM) and shoulder and elbow injuries.Purpose/Hypothesis:This study aimed to prospectively examine the relationship between hip ROM and throwing-related shoulder and elbow injuries in elementary and junior high school baseball players. The hypothesis was that players with unrestricted ROM in the hip would have a reduced risk of upper extremity injuries.Methods:The study included 263 baseball players (mean ± SD age, 10.5 ± 1.3 years; range, 7-14 years). The following physical parameters were assessed: (1) hip flexion ROM measured in the supine position and (2) hip internal and external rotation in the prone position. After the season, players completed questionnaires regarding shoulder and/or elbow injuries. For comparison, the players were classified as injured (not able to play for ≥8 days because of shoulder and/or elbow problems) or noninjured.Results:During the season, 52 players had shoulder and/or elbow injuries. When the injured and noninjured groups were compared, hip flexion on the dominant side (121.5° ± 12.0° vs 126.7° ± 9.8°, respectively; P < .01), hip flexion on the nondominant side (119.6° ± 11.7° vs 126.0° ± 9.9°, respectively; P < .01), and internal rotation on the dominant side (52.5° ± 11.3° vs 56.8° ± 10.8°, respectively; P = .01) were significantly reduced in the injured group.Conclusion:We identified preseason decreases in flexion bilaterally and internal rotation on the dominant side as risk factors for shoulder and elbow injuries in elementary and junior high school baseball players. Further studies are required to prevent disabilities in elementary and junior high school baseball players through development of prevention and intervention programs.

Relationship between Whole General Joint Laxity and Elbow Pain during Pitching in Elementary and Junior High School Baseball Players

Relationship between Whole General Joint Laxity and Elbow Pain during Pitching in Elementary and Junior High School Baseball Players

The relationship among pain, subjective evaluation, physical findings, and pitching form in junior high school baseball players

The relationship among pain, subjective evaluation, physical findings, and pitching form in junior high school baseball players

Evaluation and Issues Arising from an Injury Prevention Workshop Given by Physical Therapists for Junior High School Baseball Players Ahead of High School Entrance in Fukui Prefecture

Evaluation and Issues Arising from an Injury Prevention Workshop Given by Physical Therapists for Junior High School Baseball Players Ahead of High School Entrance in Fukui Prefecture

Shoulder and Elbow Pain in Junior High School Baseball Players - Results of a Nationwide Survey

Shoulder and Elbow Pain in Junior High School Baseball Players - Results of a Nationwide Survey

Shoulder and elbow pain in junior high school baseball players: Results of a nationwide survey

BackgroundDespite proposals and guidelines to prevent baseball injuries in young players by societies and organizations, many shoulder and elbow injuries continue to occur among junior high school baseball players. In order to investigate the training conditions of junior high school baseball players and the risk factors for shoulder and elbow pain in the players, we conducted a questionnaire survey among junior high school baseball players throughout the country. MethodsThe questionnaire survey was conducted among junior high school baseball players in September 2016. ResultsA total of 11,134 junior high school baseball players belonging to 495 teams responded to the survey. Among these, 4004 players trained every day of the week and 1151 players played baseball games every month with no off-season. Among 9752 players who did not have shoulder and/or elbow pain in the spring and summer of 2015, 19.2% of players experienced elbow pain over the course of one year, 13.6% of players experienced shoulder pain, and 28.0% complained of shoulder and/or elbow pain. The frequency of elbow pain was more than that of shoulder pain. At risk for shoulder pain were pitchers and catchers and second-year students, while risk factors for elbow pain were playing pitcher and catcher positions, pitching or throwing ≥300 balls per week, playing ≥10 games on average per month and being left-handed. ConclusionRisk factors for shoulder pain were different from those for elbow pain. To prevent elbow pain, coaches should pay attention to pitchers and catchers and left-handed players and not allow players to pitch or throw ≥300 full-power balls per week or participate in ≥10 games per month. They should also pay attention to pitchers and catchers and second-year students to prevent shoulder pain. It is important for coaches to train multiple pitchers and catchers.

Analysis of lower extremity side-reaching motion in junior high school baseball players.

[Purpose] The aim of this study was to clarify the movement pattern of the pelvis and trunk of junior high school baseball players based on the lateral reach motion of the lower limb, which is related to poor pitching movement. [Participants and Methods] Twenty-five male students belonging to a baseball club participated in this study. Each participant performed the lower limb side reach movement in the standing position, during which the movements of the knee joint, hip joint, pelvis, and trunk were analyzed. [Results] A significant correlation was found between reach distance and reach leg hip abduction, supporting leg hip abduction, trunk side bending, and trunk tilt. We found a significant correlation between reach leg hip abduction and pelvic tilt and trunk side bending and between supporting leg hip abduction and pelvic tilt, knee valgus, and trunk side bending. Furthermore, we found a significant correlation between knee valgus and lower leg tilt and trunk tilt and between trunk side bending and pelvic tilt. [Conclusion] This study suggests that in the standing position movement at this age, the hip and trunk movements are related to and affect performance.

Characteristics of Physical Functions of Junior High School Baseball Players with Throwing Pain: Evaluation Using a Simplified Functional Test

Characteristics of Physical Functions of Junior High School Baseball Players with Throwing Pain: Evaluation Using a Simplified Functional Test

Relationships between Shoulder Injuries during Throwing Motions and the Range of Motions in Junior and Senior High School Baseball Players

The purpose of this study was to assess the range of motions of the upper and the lower limbs in junior and senior high school baseball players to examine relationships between the range of motions and shoulder injuries caused during throwing motions. Significant differences in the range of motion were not shown for any of the items between the injured and the healthy groups of junior or senior high school students. The height, weight, age, years of baseball experience, and the age of starting baseball indicated a significant difference only for the weight in the injured junior high school group (p < .05). Significant differences were not shown for any other variables. The possibility of the collapse of the kinetic chain among upper extremity, lower limbs, and the trunk increases when flexibility declines. Consequently, it was expected that throwing motions would place high stresses on the upper extremity, which causes pitching-related injuries. However, the results of this study did not indicate a correlation between the range of motions and shoulder injuries.

Changes of the ultrasonographic images and the symptom of the elbow joint in junior high school baseball players over 2-year follow-up

Changes of the ultrasonographic images and the symptom of the elbow joint in junior high school baseball players over 2-year follow-up

A study of changes of shoulder rotational range of motion in primary and junior high school baseball players according to abnormal scapular positions

A study of changes of shoulder rotational range of motion in primary and junior high school baseball players according to abnormal scapular positions

中学生野球選手における身長成長速度曲線と体力要素との関係 The relationship between the Height Velocity Curve and Physical Fitness in Junior High School Baseball Players

中学生野球選手における身長成長速度曲線と体力要素との関係 The relationship between the Height Velocity Curve and Physical Fitness in Junior High School Baseball Players

中学野球選手におけるFunctional Movement Screenと投球障害の関係

中学野球選手におけるFunctional Movement Screenと投球障害の関係

Clinical Results of Mosaicplasty for Osteochondritis Dissecans of the Capitellum after Retirement of Club Activities in Junior High School Baseball Players

Clinical Results of Mosaicplasty for Osteochondritis Dissecans of the Capitellum after Retirement of Club Activities in Junior High School Baseball Players

Evaluation of the thickness of the medial ulnar collateral ligament in junior high and high school baseball players.

Thickening of the medial ulnar collateral ligament in the throwing arm of adult baseball players is a well-known phenomenon. However, onset of the thickening is unclear among young baseball players. The purpose of this study was to evaluate the thickness of the medial ulnar collateral ligament in junior high and high school baseball players. Seventy-one uninjured and asymptomatic junior high and high school baseball players were included in the study. Participants underwent physical examination after completing a questionnaire, followed by ultrasonographic evaluation. The thickness of the medial ulnar collateral ligament was measured bilaterally. The thickness of the throwing and non-throwing sides in high school and junior high school baseball players, and within each group, was compared and statistically analyzed. The medial ulnar collateral ligament in the throwing arm of high school baseball players was thicker than that in the non-throwing arm (5.5 vs. 4.4 mm), although no significant difference was seen in junior high school baseball players. High school baseball players showed a significantly thicker medial ulnar collateral ligament in the throwing arm than junior high school baseball players. Thickening of the medial ulnar collateral ligament in the throwing arm of asymptomatic and uninjured baseball players may begin by the time the players reach high school.

Relationship between Lower Extremity Tightness and Star Excursion Balance Test Performance in Junior High School Baseball Players.

[Purpose] The purpose of this study was to examine the relationship between lower extremity tightness and lower extremity balance, measured by the Star Excursion Balance Test (SEBT), in junior high school baseball players. [Subjects] Thirty-three male students belonging to baseball clubs in 2 junior high schools participated in this study. [Methods] For the SEBT, we chose to examine the anterior (ANT), posterior (POS), lateral (LAT), and medial (MED) directions. Regarding muscle tightness measurement, the angle of each joint of the bilateral iliopsoas, quadriceps, hamstring, gastrocnemius, hip internal rotator, and hip external rotator was measured. [Results] The ANT direction of the SEBT was significantly negatively correlated with gastrocnemius tightness. The MED direction of the SEBT was significantly positively correlated with hip internal rotator tightness and hamstrings tightness and significantly negatively correlated with gastrocnemius tightness. The LAT direction of the SEBT was significantly negatively correlated with iliopsoas tightness and gastrocnemius tightness. [Conclusion] Since the rate of upper extremity injury is high in these subjects and this could be due to tightness and instability of the lower extremity from a kinetic viewpoint, the SEBT could be used as a standard evaluation test when examining upper extremity injuries in young baseball players.