Glenohumeral Internal Rotation Research Articles

Shoulder external rotation contracture following neonatal brachial plexus injury

BackgroundGlenohumeral posterior external rotation contractures and scapular winging are frequently overlooked problems in residual neonatal brachial plexus injury (NBPI). Recent attention has emphasized their impact on vital functions such as feeding and hygiene. This study aims to present the epidemiology of posterior glenohumeral (GH) contractures in a significant pediatric NBPI population and explore contributing factors. MethodsWe conducted a retrospective analysis of data collected from January 2019 to November 2022, involving a case series of 262 children with residual NBPI. The data included demographics, palsy level, prior surgical history, and the modified Mallet scale. Glenohumeral passive internal rotation in abduction (IRABD) and cross-body adduction (CBADD) angles were measured bilaterally. Subjects were categorized into 'Belly-' (Mallet Hand-to-Belly <3) and 'Belly+' (Mallet Hand-to-Belly ≥3) groups. ResultsMedian participant age was 7.9 years (range: 3.5 – 21 years). Extension injury patterns included Erb's palsy (56.5%), extended Erb's palsy (28.6%), and global palsy (14.9%). Contractures exceeding 10, 20, and 30 degrees were prevalent in both IRABD and CBADD angles. The 'Belly-' group (9.5%) demonstrated a significant reduction in both angles compared to the 'Belly+' group. Weak correlations were found between IRABD (r=0.390, p<0.0001) or CBADD (r=0.163, p=0.0083) angles and Mallet hand-to-abdomen item. Glenohumeral reduction and Hoffer procedures led to a notable decrease in CBADD angle, without affecting 'Belly-' prevalence. Global injuries exhibited decreased angles compared to Erb's group. ConclusionsExternal rotation glenohumeral contractures are prevalent in residual NBPI, impacting midline access. Surprisingly, history of glenohumeral procedures or extensive injuries did not increase the likelihood of losing the ability to reach the belly. ROC analysis suggests specific thresholds for maintaining this ability.

Comparison of glenohumeral and scapulothoracic kinematics between fastballs and curveballs during baseball pitching

ABSTRACT Shoulder injuries are common in baseball pitchers and primarily involve the glenohumeral joint. Past analyses have examined shoulder biomechanics during different pitch types simply as the motion of the upper arm relative to the thorax. In this study, glenohumeral and scapulothoracic kinematics were compared between fastballs and curveballs at key timepoints throughout a pitch. Upper extremity kinematics of thirteen collegiate pitchers were collected during fastball and curveball pitches with motion capture. A linear model approach was utilised to estimate scapular kinematics based on measurable humerothoracic motion. Glenohumeral kinematics were computed from the scapular and humeral motion data. Comparisons of scapulothoracic and glenohumeral kinematic variables at times of maximum glenohumeral external rotation, ball release, and maximum glenohumeral internal rotation between pitch types were made using paired t-tests with Benjamini-Hochberg corrections. There were no significant differences in glenohumeral kinematics. Fastballs elicited significantly less scapulothoracic internal rotation and more posterior tilt at maximum glenohumeral external rotation. Fastballs produced significantly less scapulothoracic internal rotation and anterior tilt at maximum glenohumeral internal rotation. This study provides further evidence that risk of injury to the glenohumeral joint may be consistent between fastballs and curveballs and offers insights into subtle differences in scapular kinematics between pitch types.

Glenohumeral internal rotation deficit: insights into pathologic, clinical, diagnostic, and therapeutic characteristics.

Overhead athletes undergo significant biomechanical adaptations due to repetitive overhead movements, primarily affecting the glenohumeral joint. These adaptations can lead to glenohumeral internal rotation deficit (GIRD), which is characterized by posterior capsule stiffness that results in glenohumeral joint translation and a shift in the center of gravity. The severity of GIRD is dependent upon the presence of asymmetry between gained external and lost internal rotation, which is defined clinically as an asymmetry exceeding 20º; this reduces the total range of motion compared to the unaffected limb or baseline measurements. Diagnosis is challenging, as it can be mistaken for chronic scapular adaptations. To mitigate misdiagnosis, a high clinical suspicion is crucial in overhead athletes, especially those who began performing forceful overhead movements before closure of growth plates. Periodic physical examinations should establish baseline values for glenohumeral rotation and track changes in glenohumeral motion to aid in diagnosis. Symptoms of GIRD include shoulder pain, stiffness, and decreased force exertion. Magnetic resonance imaging is the preferred imaging method for evaluating GIRD and assessing concomitant soft tissue pathologies. Untreated GIRD can lead to rotator cuff strength imbalances. Treatment mainly involves conservative measures, such as physical therapy, to improve internal rotation and alleviate posterior tightness. Surgical interventions are considered when symptoms persist despite conservative treatment with physical therapy or in the presence of concomitant pathologies.

Utilizing the Pronated Forearm Technique for Measuring Glenohumeral External Rotation in Baseball Players.

Alterations in glenohumeral internal rotation (GIR), glenohumeral external rotation (GER), and total range of motion (TROM) have been linked with increased injury risk. GER capacity has been measured routinely with the forearm in neutral rotation (GERN), but a recent study reported GERN was greater than GER with the forearm in pronation (GERP) in Minor League pitchers. This work has not yet been replicated or extended to other groups. GERP would be significantly less than GERN in Independent League baseball pitchers, and there would be no difference in GERP or GERN measurements between this new group and the previous group of Minor League pitchers. Cross-sectional study. Level 3. Goniometric measurements were recorded for bilateral GIR, GERN, and GERP, and resulting TROM for 37 Independent League baseball pitchers. These data were compared with the previous study. All motions were compared individually between groups, between throwing and nonthrowing arm, and both within and between techniques (forearm neutral or pronated). GERP was significantly less than GERN for both arms within each group tested (P < 0.01). Independent League pitchers had greater between arm differences for GIR (-16.9° vs -6.9°), GERN (+15.1° vs -0.6°), and GERP (+13.1° vs -5.9°) compared with Minor League pitchers. TROM for the Independent League pitchers was not statistically different for either measurement technique, while TROM for the throwing arm of the Minor League pitchers was statistically reduced with varying effect sizes (d = 0.35-0.99) compared with the nonthrowing arm (P < 0.01). This study confirmed earlier findings that the pronated forearm resulted in decreased GER capacity, illustrating the adaptive response to throwing and the need to evaluate for this variable. GERP should be evaluated in all groups of pitchers, but there may be variations within tested groups.

The associations of physical parameters with the Closed Kinetic Chain Upper Extremity Stability Test, the Upper Quarter Y Balance Test, and the Upper Limb Rotation Test in professional overhead athletes

ObjectiveTo investigate the associations of glenohumeral internal (IR) and external rotation (ER), horizontal adduction (HA), and thoracic spine rotation ranges of motion (ROM), isometric muscle strength of the shoulder rotators, and trunk muscle endurance with the Closed Kinetic Chain Upper Extremity Stability Test (CKCUEST), the Upper Quarter Y Balance Test (YBT-UQ), and the Upper Limb Rotation Test (ULRT) in overhead athletes. DesignCross-sectional study. SettingsLaboratory. ParticipantsOne hundred twenty-one athletes were enrolled. Main outcome measuresIndependent variables were: IR, ER, HA, and thoracic spine rotation ROMs, isometric muscle strength of glenohumeral IR and ER muscles, and trunk muscle endurance. Dependent variables were: CKCUEST, YBT-UQ, ULRT. ResultsIR ROM of the nondominant side was associated with the CKCUEST, the YBT-UQ, and the ULRT. IR muscle strength of the dominant side was associated with the CKCUEST and the ULRT. Trunk flexor and lateral endurance of the dominant side were associated with the CKCUEST and the YBT-UQ, respectively. ConclusionsMany of the physical parameters influencing scores on the CKCUEST and the YBT-UQ are different. Common parameters influence the CKCUEST and ULRT scores, yet more parameters influence the CKCUEST score. We suggest the combined use of the CKCUEST and the YBT-UQ in overhead athletes.

Improved joint function when reaching behind the back is associated with patient reported outcomes in individuals with rotator cuff tears following exercise therapy

BackgroundReaching behind the back is painful for individuals with rotator cuff tears. The objectives of the study were to determine changes in glenohumeral kinematics when reaching behind the back, passive range of motion (RoM), patient reported outcomes and the relationships between kinematics and patient reported outcomes following exercise therapy. MethodsEighty-four individuals with symptomatic isolated supraspinatus tears were recruited for this prospective observational study. Glenohumeral kinematics were measured using biplane radiography during a reaching behind the back movement. Passive glenohumeral internal rotation and patient reported outcome measures were collected. Depending on data normality, appropriate tests were utilized to determine changes in variables. Spearman's correlations were utilized for associations, and Stuart-Maxwell tests for changes in distributions. FindingsMaximum active glenohumeral internal rotation increased by 3.2° (P = 0.001), contact path length decreased by 5.5% glenoid size (P = 0.022), passive glenohumeral internal rotation RoM increased by 4.9° (P = 0.001), and Western Ontario Rotator Cuff Index and American Shoulder and Elbow Surgeons scores increased by 29.8 and 21.1 (P = 0.001), respectively. Changes in Western Ontario Rotator Cuff Index scores positively associated with changes in maximum active glenohumeral internal rotation and negatively associated with changes in contact path lengths (P = 0.008 and P = 0.006, respectively). InterpretationThe reaching behind the back movement was useful in elucidating in-vivo mechanistic changes associated with patient reported outcomes. Glenohumeral joint function and patient reported outcomes improved, where changes in Western Ontario Rotator Cuff Index scores were associated with kinematics. These findings inform clinicians of functional changes following exercise therapy and new targetable treatment factors.

Prevalence of Glenohumeral Internal Rotation Deficit in Fast Bowlers and Its Correlation with Bowling Speed

Prevalence of Glenohumeral Internal Rotation Deficit in Fast Bowlers and Its Correlation with Bowling Speed

Shoulder External Over Internal Rotation Ratio Is Related to Biomechanics in Collegiate Baseball Pitching.

Altering baseball pitching mechanics affects both performance and the risk of injury. The purpose of this study is to investigate the relationships of shoulder external over internal rotation ratio (SEIR) and other shoulder rotational properties during physical exam and biomechanics of pitching for 177 collegiate baseball pitchers. The shoulder range of motion was quantitatively measured using a custom-made wireless device. Pitching motion data were collected at 240Hz, and a custom program was created to calculate the throwing arm motion and loading during baseball pitching. Linear regression and analysis of variance tests were performed to investigate the relationships between the shoulder physical exam outcomes and throwing arm biomechanics. SEIR had significant correlations with shoulder horizontal adduction angle at foot contact, maximum shoulder external rotation angle, maximum shoulder linear velocity, and elbow angle at ball release. SEIR groups had significant differences in shoulder proximal force, adduction torque, internal rotation torque, and horizontal adduction torque, and in elbow medial force and varus torque. Glenohumeral internal rotation deficit and total rotational motion deficit had no relationships with throwing arm motions or joint loadings. Shoulder health should be monitored to improve understanding of pitching mechanics in collegiate baseball pitchers.

Glenohumeral internal rotation deficit (GIRD) in young and asymptomatic elite swimmers

Context: Glenohumeral internal rotation deficit (GIRD) may affect overhead athletes and contribute to shoulder injury. The aim of our study was to assess data on passive shoulder ROM in young elite swimmers and to determine the prevalence of anatomical and pure GIRD (aGIRD and pGIRD) in a large sample size of asymptomatic elite swimmers with a new classification method. Objective: to assess data on passive shoulder ROM in young elite swimmers and investigate possible association with anthropometric data and competitive practice routine. Design: Cross-sectional study Setting: Research laboratory Patients or Other Participants: A total of 752 asymptomatic elite swimmers were by voluntary participation (391 males, 361 females; mean age, 15.88 ± 2.31 years). Passive glenohumeral rotational ROM was measured bilaterally to investigate the prevalence of aGIRD and pGIRD. Evaluations were performed with athletes at rest before any training or competition Main Outcome Measure(s): GIRD and associated aGIRD and pGIRD in elite youth swimmers by identifying a standard classification procedure. Results: GIRD was found in 136 participants (18.1%); aGIRD was present in 28 cases (3.7% of all) whereas pGIRD was observed in 108 cases (14.4% of all). No significant differences were found regarding GIRD between sex, age, age group, years of training, breathing side and distance. Swimmers classified as pGIRD showed significant less dominant Internal rotation, Total range of motion and External rotation gain (P &amp;lt; 0.01) than aGIRD; conversely, aGIRD swimmers shows significant less non-dominant IR, ER and TROM than pGIRD (P &amp;lt; 0.01). Conclusions: GIRD is a relatively common condition in asymptomatic elite youth swimmers; In order to not overestimate this condition, anatomical and pure GIRD have to be distinguished. While they play a role, the respiratory side, dominant limb, and crawl did not have a significant impact when facing an elite swimmer with GIRD.

THE MUSCULOSKELETAL PROFILE OF FEMALE ADOLESCENT ELITE WATER POLO PLAYERS AND THE FACTORS AFFECTING THROWING PERFORMANCE

The musculoskeletal (MSK) profiles of water polo players and other overhead athletes has been shown to relate to injury and throwing performance (TP). There have been no robust studies conducted on the MSK profiles and the variables affecting TP amongst female, adolescent, elite water polo players.A prospective quantitative cohort design was conducted amongst eighty-three female adolescent, elite water polo players (range 14–19 years). All participants filled out the Kerlan-Jobe Orthopaedic Clinic questionnaire, followed by a battery of screening tests aimed to identify possible MSK factors affecting TP. Pain provocation tests, range of motion (ROM), upward scapula rotation (USR), strength and pectoralis minor length measurements were all included. Participants also performed throwing speed (TS) and throwing accuracy (TA) tests.All the data collected were grouped together and analysed using SPSS 28.0. The condition for statistical significance was set as p &lt;0.05. Multi-collinearity was tested for among variables to find out inter-variable correlations. Finally, a multiple regression analysis was performed.The mean KJOC score was 82.55 ± 14.96. 26.5% tested positive for at least one of the impingement tests. The MSK profile revealed decreased internal rotation ROM, increased external rotation ROM, a downwardly rotated scapula, weak external rotators, weak serratus anterior strength, strong lower trapezius and gluteus medius strength and a shorter pectoralis minor length all on the dominant side.Age, pectoralis minor length, upper trapezius and serratus anterior strength as well as upward scapula rotation were all positively correlated with TS, while sitting height, upper trapezius and serratus anterior strength and glenohumeral internal rotation ROM were positively correlated with TA.Multiple MSK parameters were found to be related to TS and TA in elite, adolescent water polo players.

No Evidence of Short-Term Changes in Muscle Activity Elicited by Dry Needling in Chronic Unilateral Shoulder Pain Patients.

The aim of the study was to assess short-term changes in shoulder muscle activity elicited by dry needling in chronic unilateral shoulder pain patients. A double-blind, placebo-controlled clinical trial was conducted, in which 30 volunteers with unilateral shoulder pain (USP) were recruited and randomly assigned to either real or sham dry needling conditions. Pain intensity scores, pressure pain threshold (PPT), glenohumeral internal rotation angles, and electromyographic activity during isotonic shoulder tasks (shoulder flexion and extension) were assessed before, immediately and 72 h after the intervention in the infraspinatus and deltoid muscles. A single application of real dry needling resulted in lower pain intensity scores and a larger range in glenohumeral internal rotation 72 h after the intervention in comparison with sham dry needling. No differences in PPT or muscle activity were observed due to the intervention. A single application of real dry needling resulted in clinically significant changes in the short-term. No differences were detected in muscle activation in the infraspinatus or deltoid muscles. Complementary interventions and longer follow-up times may be required to observe changes in muscle activity.

Analysis of the functional performance of the shoulder in swimming athletes with and without a history of injury

Background: Swimmers have a significant potential for shoulder injuries due to the unique nature of the different styles involved in swimming, as well as the high volume of repetitions required during training, which arise through repetitive strain and microtrauma. Injuries are the most frequent due to the repetitive use of the upper limb in overhead movements and factors related to Range of Motion (ROM) and strength. Objective: To analyze the performance of the shoulder of swimming athletes and to verify if there is a difference between athletes with and without a history of injury, as well as to verify the transmission between the performance of this joint with ROM and strength values. Methods: 24 competitive swimmers were evaluated, with an average age of 20 years (± 7.9). The glenohumeral internal rotation deficit (GIRD) and internal and external rotation ROM of the shoulder were evaluated using goniometry. Shoulder functionality was assessed using the closed kinetic chain test for upper limbs (CKCUEST). Handgrip strength was also evaluated with a dynamometer. SPSS software, version 21.0, was used and data were analyzed using Pearson's collaboration test and Student's t test for independent samples. Results: Athletes with a history of injuries had a higher weekly training load, although they did not differ in terms of the number of years practicing the sport. The performance in the CKCUEST was higher in the group without a history of injury (p=0.04) and there was no difference between the groups regarding the variables of total ROM and GIRD, as well as for grip strength. There was change only between the CKCUEST power values with the grip strength (p&lt;0.05, r=0.677). Conclusion: The functional performance of the shoulder is greater in athletes without a history of injury.

Risk of injury and kinematic assessment of the shoulder biomechanics during strokes in padel players: a cross-sectional study.

Padel players commonly suffer from shoulder pain and the particularly high incidence is probably linked to the high frequency of strokes. In addition, due to the repetitive technical gesture, an adequate technique is essential in terms of performance and injury risk prevention. Aim of this study was to objectively evaluate shoulder kinematic during the athletic gesture to analyze the risk factors linked to padel strokes. Professional and amateur padel players underwent a three-dimensional motion analysis of the padel strokes utilizing optoelectronic and surface electromyography systems (BTS Bioengineering, Garbagnate Milanese, Milan, Italy). Twelve padel players were included in this study (10 professional players in Group A and 10 amateurs in Group B). Experience influences the execution of padel strokes with a significant difference between group A and B in terms of gleno-humeral rotation and scapular tilt. Moreover, a subgroup analysis revealed that male players execute voleè with a higher external rotation (P=0.043), and forehand with a higher scapular tilt (P=0.044). The results confirm that the high ranges of motion of the overhead strokes could rise the risk of slap lesion, impingement, and glenohumeral internal rotation deficit. However, a correct execution of the athletic gesture is linked with a dynamic stabilization of the humeral head. In conclusion, the kinematic analysis could help in the early identification of the kinematic alteration to build a tailored rehabilitation plan based on the athlete's needs.

Dry Needling versus Diacutaneous Fibrolysis for the Treatment of the Mechanical Properties of the Teres Major Muscle: A Randomized Clinical Trial

(1) Background: The stiffness of the posterior shoulder muscles has been shown to be related to shoulder pain and range of motion (ROM) restriction in athletes. Specifically, the treatment of the teres major muscle showed promising results in previous studies. The aim of this study was to compare the effects of dry needling (DN) vs. diacutaneous fibrolysis (DF) to improve the stiffness and tone of the teres major muscle, pain intensity, shoulder ROM, and extensibility in the short-term and at one-week follow-up in handball athletes. (2) Methods: A randomized clinical trial with blinded examiners was carried out. Elite handball athletes with shoulder pain and glenohumeral internal rotation deficit (n = 30) were randomly allocated to the DN group or the DF group. Patients in both groups received a single treatment session directly applied to the teres major muscle. The primary outcome variables and instrument were mechanical properties of the teres major muscle (stiffness and tone) measured with myotonometry. The secondary outcome variables were intensity of shoulder pain evaluated with visual analogue scale and shoulder ROM and extensibility recorded with a digital inclinometer. (3) Results: No between-group differences were found after the intervention or at one-week follow-up in the mechanical properties of teres major muscle, pain intensity, shoulder ROM, or extensibility. (4) Conclusions: the DN and DF techniques showed similar results at both timepoints in elite handball athletes with shoulder pain and glenohumeral internal rotation deficits.

Throwing Shoulder Adaptations Are Not Related to Shoulder Injury or Pain: A Preliminary Report.

Overhead throwing in baseball and softball athletes induces shoulder adaptations theorized to increase risk of shoulder musculoskeletal injury (MSI) and/or pain due to range of motion (ROM) deficits. Shoulder ROM adaptations are associated with a higher risk for developing shoulder MSI and pain. Prospective cohort study. Level 3. A total of 60 National Collegiate Athletic Association Division I athletes cleared for full athletic participation and free from upper extremity MSI in the last 4 weeks (age, 19.0 ± 1.2 years; weight, 82.1 ± 13.7 kg; height, 178.6 ± 11.2 cm; softball, n = 23; baseball, n = 37). Passive glenohumeral internal rotation (IR), external rotation (ER), and horizontal adduction (HA) ROM were measured with the scapula stabilized and used to categorize participants with/without external rotation gain (ERG), external rotation insufficiency (ERI), glenohumeral internal rotation deficit (GIRD), pathological GIRD, and posterior shoulder tightness (PST) before the competitive season. Groups were then compared to assess the incidence of shoulder MSI prospectively and prevalence of shoulder pain at the initial evaluation. Baseball and softball athletes demonstrated significantly less IR ROM in the dominant shoulder (50.6° ± 9.4°) compared with the nondominant shoulder (59.1° ± 8.6°; P < 0.01) and significantly more ER ROM (dominant, 104.6° ± 12.1°; nondominant, 97.7° ± 12.0°; P < 0.01). Incidence of shoulder MSI was 15% but was not significantly related to any shoulder adaptations. No significant relationship was found between prevalence of pain and any shoulder adaptations in the 27% of athletes with pain. Increased ER and decreased IR ROM adaptations in intercollegiate overhead throwing athletes do not appear to be correlated to risk of shoulder MSI or pain. The findings of this level 3 prospective study provide clinicians working with overhead athletes information regarding shoulder MSI risk and pain. It is recommended that clinicians should not use ROM adaptations exclusively to determine increased risk of shoulder MSI.

MODİFİYE POSTERİOR OMUZ GERME EGZERSİZLERİNİN POSTERİOR OMUZ GERGİNLİĞİ VE GLENOHUMERAL İNTERNAL ROTASYON DEFİSİTİNDEKİ ETKİNLİĞİ: BİR SİSTEMATİK DERLEME

Purpose: Posterior shoulder tightness (PST) and Glenohumeral internal rotation deficit (GIRD) can impact shoulder biomechanics and damage shoulder function. Posterior shoulder stretching exercises (PSSEs) are often performed in traditional positions to improve posterior shoulder inflexibility. However, these traditional positions can cause inadequate control of the scapula and glenohumeral rotation. The modified PSSEs through scapular stabilization are preferred as current trends to effective management of the GIRD and PST. However, there is a lack of consensus regarding which type of modified PSSE is more effective on PST and GIRD improvement. Therefore, we aimed to describe the efficacy of modified PSSEs on PST and GIRD in symptomatic and asymptomatic populations to aid clinicians when making decisions for these populations. &#x0D; Methods:A literature search was conducted for a systematic review. Relevant studies were searched from appropriate electronic databases (CINAHL, Cochrane Review, Pubmed (MEDLINE), Web of Science as well as Google Scholar©), and selected the eligible studies for inclusion.&#x0D; Results: The present systematic literature search generated 127 relevant citations and 17 articles were included in the final review. As an outcome measure GIRD was assessed in all included studies, whereas PST was assessed in 10 studies.There was high evidence related to the positive effects of both modified cross-body and sleeper stretch to improve GIRD and PST.&#x0D; Conclusion: According to this systematic literature review, both modified cross-body and sleeper stretch are effective in the improvement of GIRD and PST. Future research should focus on other specific shoulder diseases and should also recruit specific participants to address the effectiveness of modified PSSEs on GIRD and PST.

EFFECTIVENESS OF MUSCLE ENERGY TECHNIQUES ON GLENOHUMERAL INTERNAL ROTATION DEFICIT IN OVERHEAD ATHLETES: A SYSTEMATIC REVIEW

Purpose: Posterior shoulder tightness (PST) and Glenohumeral Internal Rotation Deficit (GIRD) are frequent biomechanical changes in overhead athletes. Evidence has shown that PST and the presence of GIRD increase subacromial pain syndrome. Posterior shoulder stretching exercises are used to improve posterior shoulder tightness. Muscle Energy Techniques (MET) are a long-established and effective approach, and the number of studies investigating the effects of MET on GIRD has been increasing in recent years. Despite the use of static stretching techniques in training, GIRD continues to be common in athletes performing overhead activities. Therefore, revealing the effects of MET on GIRD might be effective in determining the type of stretching most appropriate for preventing GIRD in athletes.&#x0D; Methods: We performed a systematic literature review, assessing the relevance of studies for inclusion and selecting the studies from appropriate electronic databases (CINAHL, Cochrane Review, Pubmed (MEDLINE), Web of Science as well as Google Scholar©).&#x0D; Results: The present systematic literature search generated 178 relevant citations and 8 articles were included in the final review. As an outcome measure, GIRD was assessed in all eight, whereas PST was assessed in four.&#x0D; Conclusion: According to this systematic literature review, MET is effective in the improvement of GIRD and PST in overhead athletes. Future research should focus on symptomatic shoulders and investigate the long-term benefits of MET.

Increased Tone and Stiffness of the Teres Major Muscle in Elite Handball Athletes: A Cross-Sectional Study

Background: The aim of this study was to determine whether the elite handball (HB) athletes with glenohumeral internal rotation deficit (GIRD) present differences in the mechanical properties in the teres major muscle, and strength and extensibility of the posterior shoulder tissues of the throwing shoulder (TS) compared to the non-throwing (non-TS) and non-HB athletes. Methods: A cross-sectional study was carried out, with sixty male participants: 30 HB athletes with GIRD and 30 age-matched healthy non-HB athletes. Mechanical properties of the teres major muscle were measured with MyotonPRO; also, extensibility of the posterior shoulder tissues and maximum isometric internal rotation (IR) and external rotation (ER) strength were recorded. Results: The teres major muscle of the TS in the HB group achieved a higher tone (Δ 0.34; 95% CI: 0.15, 0.53) and stiffness (Δ 30.86; 95% CI: 23.04,38.68), and a lower relaxation time compared to the non-TS of the same group (Δ −0.69; 95% CI: −1.15, −0.24;) and to the TS of the control group for the tone (Δ 0.36; 95% CI: 0.02, 0.70) and for the stiffness (Δ 27.03; 95% CI: 15.24, 38.83). The extensibility of the TS of the HB group presented a statistically significant decrease compared to the control group (Δ−7.83; 95% CI: −12.42, 3.23). A between-groups ER/IR ratio imbalance was found for the TS (Δ−12.18; 95% CI: −25.59, −1.23) and the non-TS (Δ−13.01; 95% CI: −25.79, −0.25). Conclusions: HB athletes with GIRD present a higher tone and stiffness of the teres major muscle and lack of extensibility of the tissues of the posterior part of the shoulder compared to the non-TS and to healthy non-HB athletes.

Effect of core-shoulder stability exercises on shoulder performance among throwers with glenohumeral internal rotation deficit

The study aimed to find out the effect of core-shoulder stability exercises on shoulder performance among throwers with glenohumeral internal rotation deficit (GIRD). Out of Forty-two athletes who participated, 30 subjects were selected who fulfilled the selection criteria and were randomized into 2 groups with 15 subjects in each group. Throwing accuracy (functional throwing performance index), throwing distance (overall medicine throw test), and shoulder range of motion were assessed and recorded at baseline, 3rd week, and 6th week of intervention. The control group received shoulder stability exercises while the study group received core-shoulder stability exercises 4 days per week for 6 consecutive weeks. Repeated measure ANOVA was used to see the difference between groups (groups 1 and 2) and time (baseline,3rd week, and 6th week ) Averaged across times statistically significant improvement was found in overhead medicine ball throw in the study group (Group 2) as compared to the control group with p&lt;0.05. No significant difference was found in the functional throwing performance index and range of motion when groups were compared across times. However, for all the outcome measures when compared across groups, a significant difference was found between 6th and 3rd-week scores as compared to baseline scores. This indicates improvements were seen in both groups independently. We conclude that core stability and shoulder stability training both improve the range of motion with throwing accuracy and distance. Core stability training improves throwing distance compared to shoulder stability training in subjects with GIRD.

Paper 17: Decreased Glenohumeral External Rotation is associated with Elbow Injury in Adolescent Baseball Pitchers

Objectives: To compare bilateral standard glenohumeral range of motion, humeral torsion &amp; humeral torsion-corrected glenohumeral range of motion within and between healthy adolescent baseball pitchers &amp; adolescent baseball pitchers who have an injury to the throwing elbow. Secondarily, to analyze the relationship between humeral torsion angle and glenohumeral rotational motion in adolescent pitchers. Methods: Baseball pitchers aged 13-17 were prospectively enrolled into either a healthy group, if currently pitching in the community without complaint or injured group, if they presented to clinic for an elbow injury related to pitching. Bilateral standard glenohumeral internal &amp; external rotation was measured in degrees using a bubble goniometer with the scapulothoracic joint manually stabilized. Bilateral humeral torsion angles were measured using an Ultrasound &amp; bubble goniometer and were used to calculate humeral torsion-corrected glenohumeral range of motion. Parametric tests were used to compare values within and between groups for both the dominant and non-dominant extremities with significance defined as p&lt;0.05. Pearson’s correlation was used to evaluate the relationship between humeral torsion and standard glenohumeral motion in each group. Results: Twenty-nine healthy and twenty-five injured pitchers were enrolled with no difference in age or hand dominance between groups. The dominant shoulder of both the healthy (Table 2) and injured (Table 3) groups demonstrated a significant increase in humeral retrotorsion with increased standard glenohumeral external rotation &amp; GIRD. However, no difference in humeral torsion-corrected range of motion was present within groups. Injured pitchers displayed less standard &amp; humeral torsion-corrected external rotation of the dominant shoulder as well as less standard external rotation of the non-dominant shoulder compared to the healthy pitchers (Table 4). No difference in internal rotation measurements or humeral torsion was found between groups. A moderate correlation was found between ipsilateral humeral torsion angle and standard glenohumeral external (r=0.49) &amp; internal rotation (r=-0.58) in the dominant shoulder of healthy pitchers (Figure 1) but no correlation (r&lt; 0.3) was found between these measures in the dominant shoulder of injured pitchers. Conclusions: Both healthy &amp; injured adolescent baseball pitchers displayed dominant shoulder GIRD, external rotation gain &amp; retrotorsion of the humerus. In healthy pitchers, dominant glenohumeral motion was correlated to the humeral torsion angle suggesting that the osseous adaptation of humerus significantly contributed to these findings. However, this correlation was not found in the injured pitchers, suggesting that soft tissue factors played a larger role in the development of GIRD &amp; external rotation gain in this group. Additionally, injured pitchers displayed less standard glenohumeral external rotation of both shoulders and less humeral torsion-corrected external rotation of the dominant shoulder compared to healthy pitchers. This suggests a baseline difference in the soft tissue and/or structure of the pitchers’ shoulders between groups. Glenohumeral internal rotation and humeral retrotorsion were not associated with injury status in our study. Clinically, this study suggests that rehabilitation programs including modalities to improve external rotation may be of benefit for adolescent baseball pitchers with elbow injuries &amp; further research on the structural variations of the adolescent pitching shoulder is needed. [Table: see text][Table: see text][Table: see text]