The differences of humeral torsion angle and the glenohumeral rotation angles between young right-handed and left-handed pitchers

The Role of Humeral Torsion on Glenohumeral Rotation in Injured Baseball Players

Background

Differences in rotational range of motion (ROM) compared to humeral retrotorsion (HRT)-corrected rotational ROM exist in healthy baseball athletes, but it is unclear whether these differences exist in a pathological population.

Purpose/Hypothesis

The purpose of this study was to determine if there are disparities between objectively measured differences in ROM and HRT-corrected deficits in injured baseball players. It was hypothesized that disparities would exist between (1) the side-to-side difference in glenohumeral external rotation (GER) and the HRT-corrected glenohumeral external rotation deficit (GERD) and (2) the side-to-side difference in glenohumeral internal rotation (GIR) and the HRT-corrected glenohumeral internal rotation deficit (GIRD).

Study Design

Cross-sectional study; Level of evidence, 3.

Methods

Data from 172 baseball players with shoulder or elbow injuries (45 shoulder, 127 elbow) were reviewed in July 2023. GER and GIR were measured on the injured and noninjured sides of all players, and diagnostic ultrasound was used to measure HRT. Dependent t tests were run to compare the side-to side differences in GER and GIR with the HRT-corrected GERD and GIRD, respectively.

Results

In the players with a shoulder injury, there was a significant disparity between the side-to-side difference in GER and the HRT-corrected GERD (2°± 14° vs -13°± 15°, respectively) and between the side-to-side difference in GIR and the HRT-corrected GIRD (-14°± 8° vs 2°± 9°, respectively) (P < .001 for both). Similarly, players with an elbow injury had significant disparities between the side-to-side difference in GER and the HRT-corrected GERD (6°± 9° vs -10°± 9°, respectively) and between the side-to-side difference in GIR and the HRT-corrected GIRD (-12°± 8° vs 4°± 10°, respectively) (P < .001 for both).

Conclusion

The results supported our hypothesis that there were disparities between objectively measured differences in GER and GIR compared with the HRT-corrected GERD and GIRD in injured baseball players. Consideration must be given to osseous adaptations that occur at the glenohumeral joint when evaluating and treating this population.

Adaptive pathology: new insights into the physical examination and imaging of the thrower's shoulder and elbow

Throwing with high velocity requires extremes of glenohumeral external rotation of the abducted arm where particularly high forces in the shoulder and elbow are endured. Repeated throwing leads to dominant-arm bony remodeling of the humerus, glenoid, and elbow, and multiple soft tissue changes that would be considered abnormal. Many of these features are thought to be adaptive and protective. The purpose of this work is to (1) define the concept of adaptive pathology; (2) review the mechanics of the throwing motion; (3) review pertinent physical examination and imaging findings seen in asymptomatic throwers' shoulders and elbows and describe how these changes develop and may be adaptive-allowing the thrower to perform at high levels; and then (4) review the principles of surgical treatment in the throwing athletes, which should focus on reducing symptoms, but not necessarily restoring the thrower's anatomy to normal.

Stand-up test could be a helpful adjunct for screening elbow disorders in Little League baseball players

BACKGROUND

The purpose of this study is to justify the result of the modified Stand-Up test (MSUT) in Little League baseball players and to clarify the association with sports related disorders in the elbow.

METHODS

A total of 245 (240 boys and 5 girls) Little League baseball players aged 9 to 12 underwent physical examination, elbow ultrasonography and questionnaires during a routine medical checkup. In addition, the MSUT, based on the Japanese Orthopaedic Association (JOA)'s original Stand-Up test to evaluate the risk of Locomotive syndrome, was performed.

RESULTS

Seventeen osteochondritis dissecans (OCD) of capitellum and 4 medial epicondylar fragmentation (MEF) cases were diagnosed with ultrasonography in 242 players. Based on the MSUT, five boys could not stand up from 40 cm platform with the single leg stance, two of whom complained of current elbow pain, three of whom diagnosed with a positive finding with ultrasonography. Odds ratio (95% confidence limits) of risk factors for failing to the 40 cm-MSUT with the single leg stance were: incidence of current elbow pain 5.7 (0.9-35.5); OCD (Grade 1b and 2) 8.2 (0.8-83); and MEF 19.5 (1.7-230).

CONCLUSION

Two percent of Little League baseball players were unable to stand up from a 40 cm high platform/stool with the single leg stance by the MSUT and it was associated with an increase in MEF or OCD diagnosis by ultrasonography and presence of elbow pain. These results suggest that players who failed to the 40 cm-MSUT with the single leg stance are at risk of elbow disorders. Also, these results are consistent with previous research on throwing injuries that have associated poor control in the legs or trunk with pain and injury involving the upper extremities. MSUT, a relatively simple procedure, may be a helpful adjunct for screening to estimate readiness for resuming general physical activity in Little League baseball players.

Personalized Injury Reduction Strategies in Sports Medicine: Lessons Learned from Advances in Breast Cancer Treatment: A Clinical Commentary

Background

Injury rates across sport have risen over the past twenty years, despite increased efforts in training and injury prevention. The rise in injury rates suggest that current approaches to estimating injury risk and risk management are not effective. One factor limiting progress is the inconsistency in screening, risk assessment, and risk management strategies to guide injury mitigation approaches.

Clinical Question

How can sports physical therapists identify and apply lessons learned from other healthcare fields to improve athlete injury risk and risk management strategies?

Key Results

Breast cancer mortality has consistently decreased over the last 30 years, largely attributed to advances in personalizing the prevention and treatment strategies which include modifiable and non-modifiable factors when assessing risk, the transition to personalized medicine, and the systematic approach used to investigate individual risk factors. Three critical phases have facilitated the identification and importance of individual risk factors and developing targeted, personalized strategies for breast cancer risk including: 1) Establishing the potential relationship between factors and outcomes; 2) Prospectively investigate the strength and direction of the relationship; 3) Investigating if intervening on identified factors alters prognosis.

Clinical Application

Applying lessons learned from other healthcare fields could improve shared decision making between the clinician and athlete concerning risk assessment and management. Examples include calculating only non-modifiable risk, creating individualized screening schedules based on risk assessment, or calculating the influence of each intervention on the athlete's injury risk. A systematic approach to identify and intervene on risk is needed to improve athlete outcomes.

Kinematic and kinetic comparison between preprofessional pitchers from the Dominican Republic and the United States

Introduction

Pitching biomechanical efficiency is defined as the association between pitch velocity and arm kinetics. Pitching mechanics inefficiency, an increase in arm kinetics without the resultant increase in pitch velocity, can lead to increased arm strain, increasing arm injury risk. The purpose of this study was to compare arm kinetics, elbow varus torque and shoulder force, in preprofessional United States (US) and Dominican Republic (DR) pitchers. Kinematics that are known to influence elbow varus torque and shoulder force as well as a representative of pitch velocity (hand velocity) were also compared.

Methods

A retrospective review was performed on baseball pitchers from the DR and US who participated in biomechanical evaluations conducted by the University biomechanics laboratory personnel. Three-dimensional biomechanical analyses were performed on US (n = 37) and DR (n = 37) baseball pitchers. Potential differences between US and DR pitchers were assessed through analysis of covariance with 95% confidence intervals [95% confidence Interval (CI)].

Results

Preprofessional DR pitchers experienced increased elbow varus torque compared with their US counterparts [DR: 7.5 (1.1); US: 5.9 (1.1) %BWxH; Beta: -2.0 (95% CI: -2.7, -1.2) %BWxH], despite throwing fastballs with slower hand velocity [DR: 3,967.1 (939.4); US: 5,109.1 (613.8) °/s; Beta: 1,129.5 (95% CI: 677.5, 1,581.4) °/s]. DR and US pitchers demonstrated similar shoulder force [DR: 136.8 (23.8); US: 155.0 (25.7); Beta: 0.4 (95% CI: -1.2, 19.7) %BW].

Discussion

Increased elbow varus torque although decreased hand velocity suggests inefficient pitching mechanics among DR pitchers. Inefficient pitching mechanics and increased elbow torque should be considered when developing training programs and pitching plans for professional pitchers from the Dominican Republic.

Development of an Injury Burden Prediction Model in Professional Baseball Pitchers

Background

Baseball injuries are a significant problem and have increased in incidence over the last decade. Reporting injury incidence only gives context to rate but not in relation to severity or injury time loss.

Hypothesis/Purpose

The purpose of this study was to 1) incorporate both modifiable and non-modifiable factors to develop an arm injury burden prediction model in Minor League Baseball (MiLB) pitchers; and 2) understand how the model performs separately on elbow and shoulder injury burden.

Study Design

Prospective longitudinal study.

Methods

The study was conducted from 2013 to 2019 on MiLB pitchers. Pitchers were evaluated in spring training arm for shoulder range of motion and injuries were followed throughout the season. A model to predict arm injury burden was produced using zero inflated negative binomial regression. Internal validation was performed using ten-fold cross validation. Subgroup analyses were performed for elbow and shoulder separately. Model performance was assessed with root mean square error (RMSE), model fit (R2), and calibration with 95% confidence intervals (95% CI).

Results

Two-hundred, ninety-seven pitchers (94 injuries) were included with an injury incidence of 1.15 arm injuries per 1000 athletic exposures. Median days lost to an arm injury was 58 (11, 106). The final model demonstrated good prediction ability (RMSE: 11.9 days, R2: 0.80) and a calibration slope of 0.98 (95% CI: 0.92, 1.04). A separate elbow model demonstrated weaker predictive performance (RMSE: 21.3; R2: 0.42; calibration: 1.25 [1.16, 1.34]), as did a separate shoulder model (RMSE: 17.9; R2: 0.57; calibration: 1.01 [0.92, 1.10]).

Conclusions

The injury burden prediction model demonstrated excellent performance. Caution should be advised with predictions between one to 14 days lost to arm injury. Separate elbow and shoulder prediction models demonstrated decreased performance. The inclusion of both modifiable and non-modifiable factors into a comprehensive injury burden model provides the most accurate prediction of days lost in professional pitchers.

Level of Evidence

2.

Glenohumeral Internal Rotation Deficit in the Adolescent Overhead Athlete: A Systematic Review and Meta-Analysis

OBJECTIVE

The objective of this review was to investigate the average glenohumeral internal rotation deficit (GIRD) in the dominant arm of adolescent overhead athletes and to examine the association with shoulder and elbow injuries.

DESIGN

Systematic review and meta-analysis.

SETTING

MEDLINE, Embase, and PubMed were searched from inception to August 1, 2020.

PARTICIPANTS

Adolescent overhead athletes with glenohumeral range of motion (ROM) measurements.

INTERVENTIONS

Nonoperative treatments of GIRD.

MAIN OUTCOME MEASURES

Glenohumeral ROM measurements comparing the dominant and nondominant extremities were pooled in a meta-analysis.

RESULTS

Twenty-five studies were included in this review, which involved 2522 overhead athletes. Pooled internal rotation (IR) deficit of the dominant arm was 9.60° (95% confidence interval [CI] 7.87°-11.32°, P < 0.00001), with an external rotation (ER) gain of 6.78° (95% CI 4.97°-8.59°, P < 0.00001) and a total ROM (TROM) deficit of 1.78° (95% CI -0.70° to 4.26°, P = 0.16). The association between GIRD and shoulder or elbow injury was not clearly defined. Two studies reported treatment, and both used nonoperative treatment in the form of physiotherapy and sleeper stretches.

CONCLUSIONS

The adolescent overhead athlete has roughly 10° of IR deficit in their dominant arm, accompanied by nearly 7° of ER gain, with similar ROM measurements for injured and uninjured athletes. Those with pathological GIRD have a greater degree of IR deficit, but without an accompanying compensatory increase in ER, leading to a TROM deficit of nearly 15°. Surgical treatment in the absence of other indications is rare, whereas physiotherapy and sleeper stretches remain the first-line treatment.

Differences in Glenohumeral Range of Motion and Humeral Torsion Between Right-Handed and Left-Handed Professional Baseball Pitchers

BACKGROUND

Elite pitchers have demonstrated significant differences in glenohumeral range of motion and humeral torsion compared with the nonthrowing population. Furthermore, abnormal shoulder range of motion measurements have been associated with different injury risks and challenges in assessing rehabilitation progress. Variations in range of motion and torsion due to handedness in the asymptomatic professional population have yet to be investigated in the literature.

HYPOTHESIS

No significant differences in glenohumeral range of motion and humeral torsion would exist between asymptomatic right- and left-handed professional pitchers.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

217 Major League Baseball pitchers from a single organization were evaluated over a 7-year period between 2013 and 2020. Range of motion was measured with a standard goniometer. Ultrasound scanning was used to determine neutral position of the shoulder, and the degree of humeral torsion was measured with a goniometer.

RESULTS

Right-handed pitchers demonstrated significantly greater values of glenohumeral external rotation (118.5° vs 112.7°; P < .001) in their throwing arms compared with their left-handed counterparts. Right-handed pitchers also showed greater values of glenohumeral internal rotation deficit (13.9° vs 4.8°; P < .001) and side-to-side differences in humeral retrotorsion (-23.1° vs -2.2°; P < .001). Left-handed pitchers demonstrated significantly greater flexion deficits in the throwing arm compared with their right-handed counterparts (7.5° vs 0.0°; P < .001).

CONCLUSION

In the throwing arm, right-handed pitchers demonstrated significantly greater measures of external rotation, glenohumeral internal rotation deficit, and humeral retrotorsion compared with left-handed counterparts. Furthermore, right-handed pitchers demonstrated a significant side-to-side difference in retrotorsion, whereas left-handed pitchers did not. However, left-handed pitchers demonstrated a side-to-side shoulder flexion deficit that was not present in the cohort of right-handed pitchers. The correlation between humeral retrotorsion and increased external rotation indicates that osseous adaptations may play a role in range of motion differences associated with handedness. Additionally, these findings may explain observed differences in several throwing metrics between right- and left-handed pitchers. Knowledge of these differences can inform rehabilitation programs and shoulder maintenance regimens.

The Reliability and Validity of a Clinical Measurement Proposed to Quantify Humeral Torsion

BACKGROUND

Range of motion (ROM) impairments of the overhead athletes' shoulder are commonly addressed through mobility-based treatments, however, adaptations from humeral torsion (HT) are not amenable to such interventions. A clinical measurement to quantify HT has been proposed, however, the validity is not conclusive.

PURPOSE

The primary aim of this study is to determine the intrarater reliability and standard error of measurement (SEM) of the biceps forearm angle (BFA) measurement. The secondary aim of this study is to investigate the convergent validity of the BFA compared to diagnostic ultrasound.

STUDY DESIGN

Cross Sectional Reliability and Validity Study.

METHODS

HT measurements, utilizing diagnostic ultrasound, were compared to BFA in 74 shoulders (37 subjects) over two sessions. Each measurement was performed three times and a third investigator recorded measures to ensure blinding. Reliability was investigated using utilizing an intraclass correlation coefficient (ICC 3,k).

RESULTS

Intrarater reliability values were 0.923 and 0.849 for diagnostic ultrasound and BFA methods respectively. Convergent validity was r = 0.566. The standard error of measurement for diagnostic ultrasound and BFA was 3° and 5°, respectively. The 95% limits of agreement between the two measurement methods were -24.80° and 19.80° with a mean difference of -2.50° indicating that on average the diagnostic ultrasound measurement was lower than that of the BFA method.

CONCLUSION

The BFA is a reliable clinical method for quantifying HT, however, demonstrates moderate to poor convergent validity when compared to diagnostic ultrasound.

LEVEL OF EVIDENCE

2b.

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

Background

The 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.

Methods

The 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.

Results

Fifty-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.

Conclusion

The 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.

Relationship between glenohumeral internal rotation deficit and shoulder conditions in professional baseball pitchers

BACKGROUND

Previous studies have reported that glenohumeral internal rotation deficit (GIRD) may increase the risk of throwing-shoulder injuries. The purpose of this study was to analyze the conditions of the throwing shoulder in professional baseball pitchers with GIRD by comparing with those in pitchers without GIRD.

METHODS

In total, 26 male professional baseball pitchers participated in this study. We evaluated passive range of motion (ROM) and isometric muscle strength at internal rotation (IR) and external rotation (ER) at 90° of abduction, as well as the muscle thickness of the supraspinatus (SSP) and infraspinatus (ISP) by ultrasound. The pitchers were divided into 2 groups: those who exhibited a loss of IR of ≥20° in the throwing shoulder (GIRD group) and those who did not (non-GIRD group).

RESULTS

In the GIRD group, the total ROM deficit (throwing side - non-throwing side) (P < .001), the muscle thickness ratio (throwing to non-throwing) of the SSP and ISP (P = .017 and P = .014, respectively), and the muscle strength ratio (throwing to non-throwing) of ER (P = .028) were significantly lower than those in the non-GIRD group. In contrast, the muscle strength ratio (throwing to non-throwing) of IR was significantly higher in the GIRD group than in the non-GIRD group (P = .0064).

CONCLUSIONS

We have shown that GIRD has significant correlations with several conditions, such as atrophy of the SSP and ISP, weakness of ER strength, enhancement of IR strength, limitation of total ROM, and throwing side, all of which could be important factors for throwing-shoulder injuries.

Evaluation of glenohumeral range of motion and humeral retroversion at ages after major change and differences in wrestlers

PURPOSE

This study aimed to present the change in humeral retroversion (HR) angle (HRA) that occurs in childhood and young adulthood and the potential developmental difference that is observed in wrestlers.

METHODS

HRA of dominant and non-dominant shoulders (DSHRA and NDSHRA, respectively) were measured using ultrasonography in a group of 30 wrestlers who started wrestling before the age of 13 years (Group 1), a group of 30 young adults, aged between 16-20 years, who were not actively engaged in any branch of overhead sports (Group 2) and a group of children aged between 11-13 years and not actively engaged in any branch of overhead sports (Group 3). Range of motion (ROM) degrees of dominant and non-dominant shoulders in all groups were compared within each group and between the groups.

RESULTS

DSHRA (mean: 88.73°, 88.93° and 89.40°) values were significantly higher than NDSHRA (mean: 81.13°, 81.83° and 84.37°) values (p < 0.001, p < 0.001 and p < 0,05) in Groups I, II and III, respectively. Internal rotation and total ROM degrees of the dominant shoulder in Group 1 and 3 were higher than those in Group 2.

CONCLUSION

There is no significant change in terms of HRA in people aged between 11-13 and 16-20 years because of natural development or wrestling. DSHRA values are higher than NDSHRA ones. In contrast to the shoulders of throwers, the shoulders of wrestlers are characterized by an increase in internal rotation, described as "Wrestler's shoulder."

LEVEL OF EVIDENCE

Level III.

Risk factor for elbow symptom manifestation in young baseball players with asymptomatic medial elbow abnormalities: a prospective cohort study

Asymptomatic elbow abnormalities are relatively common in young baseball players, but the factors responsible are unclear. To prospectively identify risk factors related to symptom manifestation in asymptomatic elbow abnormalities, we recruited 573 baseball players (age: 7-14 years) at a pre-participation medical/physical examination in the preseason who were right-handed and had asymptomatic medial elbow abnormalities on ultrasound (US). Baseline preseason and postseason participant characteristics were assessed. A "symptomatic" elbow was defined as an elbow with medial elbow joint problems that prevented ball throwing for ≥ 8 days. After exclusions, 82 players were enrolled, of whom 22 (26.8%) developed a symptomatic elbow. In univariate analyses, the external and internal rotation strengths of the dominant shoulder were significantly greater in the symptomatic group than in the asymptomatic group (P = 0.021). Multivariate logistic regression analysis showed that the internal rotation strength of the dominant shoulder was a significant independent risk factor (odds ratio = 1.091, P = 0.027) for developing a symptomatic elbow. In young asymptomatic baseball players with abnormalities in the medial elbow region of the dominant arm on US, stronger preseason internal rotation strength of the dominant shoulder was a significant independent risk factor for the development of a "symptomatic" elbow.

Relationship of clinical measures with humeral torsion in young adults: a pilot study

PURPOSE

Humeral retroversion alters range of motion and has been linked to injury risk. Clinically,palpation of the bicipital groove is used to quantify humeral torsion, but the accuracy of this procedure has not been fully examined. The purpose of this study was to investigate the relationship between clinical and diagnostic ultrasound (US) assessment of humeral torsion while considering shoulder position of the participant and clinical expertise of the examiner.

METHODS

Seventeen participants (34 shoulders, 16/17 right handed, 10/17 history of throwing) were recruited. US was assessed by an experienced assessor. Two clinical assessments of humeral torsion were performed by two assessors of different experience (expert and novice). Humeral torsion was assessed at 90 degrees shoulder abduction (Palp90) and 45 degrees shoulder abduction (Palp45). Within assessor intraclass correlation coefficients (ICC (3, 1) were calculated. Correlation coefficients (Pearson's) were generated to determine relationship between clinical and US examination findings.

RESULTS

Intra-rater reliability for clinical tests were good (ICCs .73 - .92) for both raters. Of the palpation tests, only the expert assessor was significantly correlated to the US measurement (p<.001) at Palp45 (r = .64) and Palp90 (r = .62). For the expert, there was a significantly lower angle calculated for Palp45 compared to Palp90 (p<.001).

CONCLUSION

The accuracy of both palpation methods for assessing humeral retrotorsion may depend on the training background of the assessor. Further, the glenohumeral position of the patient during palpation should be consistent for the purposes of repeated testing.

Shoulder ranges of motion and humeral torsions of injured baseball players have different characteristics depending on their pitching sides

Background

Right- and left-side throwers in baseball may have different shoulder conditions and throwing biomechanics. This study aimed to compare the passive range of motion, humeral torsion, and clinical findings between right- and left-handed throwers who sustained throwing shoulder injuries and confirm the differences in the characteristics between throwing sides.

Methods

A total of 52 pitchers diagnosed with throwing shoulder injuries were included in this study: 27 patients were right-side throwers (R group), and 25 were left-side throwers (L group). We measured the bilateral passive external and internal rotation angles in abduction position (ABIR) and total arc at their first visit. To assess posterior shoulder tightness, the internal rotation angles in forward flexion (FIR), and the abduction angle (AA) and horizontal flexion angle (HFA) without scapula motion were measured. The bilateral humeral torsion angles were also measured using ultrasonography. These values were compared between the participants' throwing and non-throwing sides and between the R and L groups' throwing sides. Furthermore, several physical findings in the shoulders were assessed, and the positive ratio was compared between the R and L groups.

Results

On comparing the throwing and non-throwing sides, the R group had significantly greater external rotation angles in the abduction position and humeral torsion angle, and smaller ABIR, total arc, FIR, AA, and HFA in the throwing side, while the L group showed no significant differences, except for a smaller ABIR and larger HFA in the throwing side. On comparing the throwing side between the R and L groups, the R group had a smaller FIR, AA, and FHA than the L group. Regarding the physical findings, the posterior jerk test, Kim test, anterior and posterior drawer sign, sulcus sign, and scapular winging in the L group were significantly more positive than in the R group.

Conclusion

The range of motion and humeral torsions differed between the left- and right-side throwers, as did the pathology between their throwing sides. Clinicians should consider the possibility that the pathological condition differs between left- and right-side throwers.

Ulnar Collateral Ligament Reconstruction With the Modified Jobe Technique in Baseball Pitchers

Background:

Tearing and insufficiency of the ulnar collateral ligament (UCL) of the elbow result in valgus instability, which can lead to pain while throwing and decline in performance in overhead athletes.

Purpose:

To assess the clinical results of a modified UCL reconstruction technique using 1 bone hole in the ulna and 1 bone tunnel in the humerus in baseball players.

Study Design:

Case series; Level of evidence, 4.

Methods:

The inclusion criteria were medial elbow pain preventing effective playing, clinically medial elbow laxity, and magnetic resonance imaging results consistent with UCL injury. Patients who were engaged in other sports and in other positions in baseball except pitchers were excluded from this study. Our modified Tommy John procedure was performed via a muscle-splitting approach and an original single-bone-tunnel technique, using a suture anchor. After a minimum of 24 months, patients were evaluated using the Conway scale and the Timmerman-Andrews score.

Results:

Of 31 patients, 20 baseball pitchers (20 male: 5 high school, 5 collegiate, 8 nonprofessional, and 2 professional pitchers) were reviewed. The mean patient age at the time of operation was 21.9 years, and the mean postoperative follow-up period was 35.1 months (range, 24-66 months). The mean Timmerman-Andrews subjective score improved significantly from pre- to postoperatively (from 68.3 to 98.3; P < .05); the objective score also improved significantly (from 81.1 to 96.4; P = .01). No complications were detected at the latest follow-up. Overall, 19 patients were able to return to their preinjury level of sports or higher.

Conclusion:

UCL reconstruction with 1 bone hole in the ulna and 1 bone tunnel in the humerus demonstrated satisfactory results in baseball pitchers. Our modified technique was safe and achieved satisfactory clinical results, with a 95% rate of return to sports.

Characteristics of Femoral Torsion Angles and Relationships Between Femoral Torsion Angles and Hip Rotational Motion Variables in Adult Baseball Players

Background:

Abnormalities in hip rotational motion (HRM) are risk factors for throwing injuries. To evaluate hip rotational motion, it is necessary to assess the torsion angle. However, no studies have investigated the femoral torsion angle (FTA) in baseball players.

Purpose:

To investigate differences in hip FTA of adult baseball players through use of ultrasonography to evaluate the relationship between the FTA and HRM.

Study Design:

Cross-sectional study; Level of evidence, 3.

Methods:

A total of 149 elite male baseball players (mean age, 20.0 ± 1.8 years; 64 pitchers, 85 position players) were enrolled in this study. Ultrasonographic assessment of FTA was performed based on the tilting angles of the anterior surface of the femoral neck and condylar axis. The hip internal rotation (HIR) and hip external rotation (HER) were assessed at 0° and 90° of flexion. Data related to FTA and HRM were compared between hips and between pitchers and position players.

Results:

No significant difference was observed in the FTAs between hips for any player (lead hip, 20.5° ± 9.2°; trail hip, 19.6° ± 9.8°; P = .276). No significant difference was observed in FTAs of both hips between pitchers and position players (lead hip, 20.1° ± 9.4° and 20.9° ± 9.0°, respectively, P = .957; trail hip, 19.5° ± 9.8° and 19.7° ± 9.8°, P = .999). In terms of HER in 90° of hip flexion in both hips, significant differences were observed in HRM variables between pitchers and position players (lead hip, 33.0° ± 8.9° and 37.5° ± 9.8°, respectively, P = .024; trail hip, 35.6° ± 9.6° and 40.4° ± 10.2°, P = .035). Linear regression analysis revealed a significant agreement between the FTA and HIR at both 0° (R = 0.298, P < .001) and 90° of hip flexion (R = 0.279, P < .001).

Conclusion:

Our findings indicated that FTAs were not different between the hips of elite baseball players. Abnormalities of the HRM are not caused by differences in the FTA but rather involve soft tissue tightness around the hip area or other bony morphologic factors in the hip joint.

Ultrasonographic Assessment of Femoral Torsion Angle Based on Tilting Angles of Femoral Neck and Condylar Axis

Femoral anteversion has been assessed with ultrasound using femoral neck tilting angle (FN-TA); however, femoral torsion angle (FTA), which is defined using FN-TA and condylar axis tilting angle, has not been assessed with ultrasound. This study aimed to establish the ultrasonographic assessment of FTA (US-FTA) by comparing data obtained through US-FTA and computed tomography (CT). Twenty-one patients (age range, 38-82 y) with 21 intact hips were included. In the US-FTA, the femoral head and anterior tubercle of the greater trochanter were used as bony landmarks. The intra-rater and inter-rater reliabilities and standard error of measurement (SEM) of US-FTA were 0.994 (SEM 0.93) and 0.994 (SEM 0.94), respectively. A strong agreement was found between FTA variables obtained with ultrasound and CT (R = 0.939, p < 0.001). Ultrasound is useful and can be a valid alternative to CT for the evaluation of the femoral torsion angle without radiation exposure.