Glenohumeral Internal Rotation Range Research Articles

Influences of Doorway Stretching with Scapular Posterior Tilt on Glenohumeral Internal Rotation Range of Motion

Influences of Doorway Stretching with Scapular Posterior Tilt on Glenohumeral Internal Rotation Range of Motion

Poster 142: Identifying the Bony and Soft Tissue Mechanisms Responsible for Glenohumeral Internal Rotation Range of Motion

Objectives:Shoulder and elbow injuries account for about one-fourth of the total injuries in professional baseball players. The loss of shoulder internal rotation range of motion (IR ROM) has been identified as a significant risk factor for upper extremity injuries in pitchers across all ages. Several anatomic structures have been independently associated with IR ROM. First, greater amounts of humeral retroversion (HR) have been related to decreased IR ROM. Second, increased posterior capsule thickness (PCT) has also been related to decreased IR ROM. Lastly, adaptations to the teres minor muscle pennation angle (PA) has been related to losses in IR ROM and the PA of both the infraspinatus and teres minor have been related to the acute decrease in IR ROM following pitching. However, these three anatomic structures have not been collectively measured in baseball pitchers to determine the underlying mechanisms responsible for IR ROM. Therefore, this study will determine the contributions of HR, PCT, and posterior rotator cuff PA on IR ROM in healthy professional baseball pitchers. We hypothesized that HR, PCT, and posterior rotator cuff PA would have a significant contribution to IR ROM.Methods:51 healthy professional pitchers were recruited for this cross-sectional study at the beginning of the 2021 Major League Baseball spring training. Participants received a bilateral IR ROM assessment while laying supine with the shoulder at 90 degrees of abduction and the scapula stabilized. Ultrasound imaging was also performed bilaterally to assess HR, PCT, infraspinatus (superficial + deep) PA, and teres minor (superficial + deep) PA. All ultrasound imaging was performed utilizing a previously published standardized technique. A stepwise regression was performed which included both arms to determine the mechanisms of IR ROM.Results:The first variable to enter into the stepwise regression model was HR which had a moderate relationship with IR ROM (regression coefficient of -0.502). PCT also entered the model, as measuring both HR and PCT improved the relationship with IR ROM from moderate to strong (regression coefficient of -0.657). Infraspinatus and teres minor PA did not enter the predictive model of IR ROM.Conclusions:HR and PCT were found to be the primary anatomic mechanisms responsible for glenohumeral IR ROM. Surprisingly, the posterior rotator cuff PA was not found to be a significant predictor of IR ROM. The posterior rotator cuff may instead contribute more to the acute decrease in IR ROM following pitching, which has recently been reported. As deficits in IR ROM can have harmful effects in baseball pitchers, understanding which anatomic structures are most responsible for IR ROM is important for injury prevention and treatment.Figure 1.Ultrasound image of the infraspinatus, with yellow arrows indicated the superficial infraspinatus pennation angle and green arrows representing the deep infraspinatus pennation angle.CT=central tendon, SN=suprascapular notch.Table 1.Standardized regression coefficients and regression strengths of included and excluded variables in the internal rotation range of motion model.

Posterior shoulder capsule of the dominant arm is stiffer in baseball players than that in nonthrowing population.

Posterior shoulder capsule tightness is one of the factors for shoulder injuries in overhead athletes. Recent studies have shown the posterior capsule of the dominant arm to be stiffer than that of the nondominant arm in baseball players. However, whether posterior capsule tightness in the dominant arm is exclusive to overhead athletes remains unknown. This study aimed to investigate whether the posterior shoulder capsule of the dominant arm in baseball players is stiffer than that in nonthrowing population. Fifteen male collegiate asymptomatic baseball players (baseball-player group) and fifteen male college students who did not partake in overhead sports (nonthrowing group) participated in this study. We measured the shear moduli of the middle and inferior posterior capsules, superior infraspinatus, inferior infraspinatus, teres minor, and posterior deltoid in the dominant arm by ultrasound shear wave elastography. We compared shear moduli between the two groups using an independent samples t-test and Mann-Whitney test. In addition, we investigated the correlation between the range of glenohumeral internal rotation and each shear modulus in each group using the Pearson correlation coefficient. The shear moduli in the baseball-player group were significantly higher than those in the nonthrowing group in both the middle posterior capsule (baseball-player group: 36.1±5.6kPa vs. nonthrowing group: 29.0±8.6kPa; P=.018) and inferior posterior capsule (37.1±9.6kPa vs. 27.9±6.8kPa; P=.002). However, no difference in the shear moduli of individual muscle groups was identified. The glenohumeral internal rotation range exhibited a statistically significant negative correlation with the shear modulus of the inferior posterior capsule in the baseball-player group (Pearson correlation coefficient=-0.586, P=.022). Our findings suggest that the posterior shoulder capsule of the dominant arm in baseball players is stiffer than that in nonthrowing population.

Acute effects of softball pitching to fatigue on the glenohumeral internal rotation range of motion

BACKGROUND: The effects of baseball pitching on the glenohumeral joint (GHJ) range of motion (ROM) have been widely studied. Specifically, internal rotation (IR) ROM reduction of the pitching arm, an adaptation to repeated overhead throwing, is linked to increased risk of injuries in baseball pitchers. However, there is a lack of literature on the effects of softball pitching on the GHJ ROM. HYPOTHESIS: Softball pitching to fatigue will result in significant reduction of GHJ supine IR ROM. DESIGN: Test–retest, quasi-experimental study. METHODS: Twelve softball pitchers (age: 19.5 ± 1.8 years) volunteered to participate in this study. GHJ ROM in supine IR, horizontal adduction, low flexion (shoulder joint flexed to 60°; added IR), extension with IR (shoulder joint abducted to 60° in the plane of scapula and then horizontally abducted 90° with the elbow maintained in 90° flexion; add GH IR), and supine external rotation were compared before and after a single bout of softball pitching to fatigue or a maximum of 100 pitches, whichever occurred first. RESULTS: Maximum ROM change post softball pitching was observed in horizontal adduction but not in supine IR. CONCLUSIONS: Maximum ROM change was observed in horizontal adduction. Supine IR ROM measurement may not be appropriate for assessing softball pitchers' shoulder ROM because this measurement was not affected by the softball pitching.

The effect of manual inter-structural release on glenohumeral internal rotation range and gliding between the infraspinatus and posterior deltoid

Introduction: Shoulder pain in overhead athletes may be related to posterior tightness of the glenohumeral joint, which may be caused by the posterior deltoid, infraspinatus, and teres minor along with the capsule. One method of relieving posterior tightness is “sleeper stretch” in which the arm is inwardly rotated during shoulder joint flexion. However, adhesion may require a more direct intervention such as manual inter-structural release (ISR) to improve the durability of post-intervention effects. This study investigated the effects of ISR between the posterior deltoid and infraspinatus on the gliding behavior of the muscles as well as the range of motion.

Glenohumeral Internal Rotation Deficit and Injuries: A Systematic Review and Meta-analysis.

Background:There is an association between throwing activity and glenohumeral internal rotation deficit (GIRD). An 18° to 20° deficit has been adopted as the standard definition of pathological GIRD, but specific findings as to how GIRD relates to an injury are inconsistent.Purpose:To systematically review the literature to clarify the definition of GIRD diagnosis for adolescent and adult overhead athletes and to examine the association between GIRD and an increased risk of injuries in these athletes.Study Design:Systematic review; Level of evidence, 4.Methods:A systematic review of the literature was performed. Observational studies comparing glenohumeral internal rotation range of motion (ROM) in injured and uninjured overhead athletes were included for the meta-analysis. Studies of adolescent and adult athletes were analyzed separately. ROM was compared for the injured and uninjured groups, and a weighted mean GIRD was estimated. To account for potential heterogeneity across studies, both fixed- and random-effects models were used to calculate a standardized mean difference (SMD).Results:Nine studies of level 3 or 4 evidence were included. From these, 12 study groups (4 adolescent, 8 adult) comprising 819 overhead athletes (226 injured, 593 uninjured) were included in the meta-analysis. The estimated SMD in GIRD between the injured and uninjured groups was 0.46 (95% CI, 0.15-0.77; P < .01) for the overall sample. The between-group effect was larger for adults (SMD, 0.60 [95% CI, 0.18 to 1.02]; P < .01) than adolescents (SMD, 0.20 [95% CI, –0.24 to 0.63]; P = .13). The weighted mean GIRD for the injured and uninjured groups was 13.8° ± 5.6° and 9.6° ± 3.0°, respectively, which also differed by age group. Moderate study heterogeneity was observed (I 2 = 69.0%).Conclusion:Based on this systematic review, the current definition of pathological GIRD may be too conservative, and a distinct definition may be required for adolescent and adult athletes. While the results indicate a link between internal rotation deficits and upper extremity injuries in the overhead athlete, higher quality prospective research is needed to clarify the role that GIRD plays in future injuries to overhead athletes of various ages.

Effects of Self-Myofascial Release on Shoulder Function and Perception in Adolescent Tennis Players.

Tennis induces a decreased internal rotation range of motion at the dominant glenohumeral joint. The effects of self-myofascial release have not yet been investigated to restore glenohumeral range of motion. This study aimed at investigating the effects of self-myofascial release on shoulder function and perception in adolescent tennis players. Test-retest design. Tennis training sport facilities. Eleven male players participated in this study (age: 15 [3]y; height: 173.1 [11.1]cm; mass: 56.0 [15.1]kg; International Tennis Number: 3). During 5 weeks, the players performed their regular tennis training. During 5 additional weeks, self-myofascial release of the infraspinatus and pectoralis muscles was implemented 3 times per week after the warm-up of the regular training session. The primary outcome was glenohumeral internal rotation range of motion. The secondary outcomes were perceived shoulder instability and tennis serve accuracy and velocity. Adding self-myofascial release allowed an increase of 11° (2°) of internal rotation range of motion at the dominant glenohumeral joint (P < .001) and a decreased perception of shoulder instability (P = .03), while maintaining tennis serve velocity and accuracy. Implementing self-myofascial release on infraspinatus and pectoralis muscles 3 times per week during 5 weeks improved dominant glenohumeral internal rotation range of motion in tennis players. It can be used as a strategy to preserve the mobility of this joint.

Acute effects of self-myofascial release and stretching in overhead athletes with GIRD

ObjectiveTo examine the acute effects of self-myofascial release (SMR), static stretching (SS), and the combination of self-myofascial release and static stretching (SMR + SS) on glenohumeral internal rotation range of motion (GH IR ROM) in overhead athletes with glenohumeral internal rotation deficit (GIRD). ParticipantsTwelve asymptomatic adult male amateur softball position players exhibiting GIRD. ResultsAll three methods significantly improved GH IR ROM. Post hoc testing revealed that SS alone and SMR + SS improved GH IR ROM significantly more than SMR alone. However, there were no significant differences in GH IR ROM between SS alone and SMR + SS. ConclusionsIf an athlete has a limited time to perform a warm-up (e.g., 3–4 min), SS alone is recommended to improve GH IR ROM. However, if the athlete has more time available to warm up (e.g., 7–8 min), combining SMR + SS may result in a greater increase in GH IR ROM.

A Randomized and Blinded Study for the Treatment of Glenohumeral Internal Rotation Range of Motion Restriction: The Prone-Passive Stretching Technique

A Randomized and Blinded Study for the Treatment of Glenohumeral Internal Rotation Range of Motion Restriction: The Prone-Passive Stretching Technique

Immediate effects of an end-range mobilization technique on shoulder range of motion and skin temperature in individuals with posterior shoulder tightness.

[Purpose] This study investigated the effects of an end-range mobilization technique on the range of motion of the glenohumeral internal rotation and the skin temperature of the shoulder in individuals with posterior shoulder tightness. [Subjects] Thirteen subjects with posterior shoulder tightness who had glenohumeral internal rotation deficit ≥ 15° participated. [Methods] All subjects underwent glenohumeral joint end-range mobilization intervention. The internal rotation range of motion of the glenohumeral joint was measured by a goniometer and the shoulder skin temperature was measured by a digital infrared thermographic imaging device before and immediately after the intervention. Paired t-tests were used to analyze the differences in these parameter pre and post-intervention. [Results] The glenohumeral internal rotation range of motion and skin temperature of the posterolateral shoulder in increased significantly post-intervention. [Conclusion] The end-range mobilization technique is effective for increasing the glenohumeral internal rotation range of motion and skin temperature of the shoulder in individuals with posterior shoulder tightness.

Improvements in Shoulder Endurance Following a Baseball-Specific Strengthening Program in High School Baseball Players

Background:The posterior shoulder muscles play key roles in maintaining shoulder function in throwing. Arm fatigue has been identified as a risk factor for shoulder and elbow pain in youth baseball pitchers. However, endurance of the posterior shoulder muscles in overhead athletes is not routinely examined or conditioned.Hypothesis:Upper extremity muscular endurance can be improved in adolescent baseball players during a 20-week preseason training program. Secondarily, strength will be improved. Finally, these improvements will be associated with maintenance of range of motion.Study Design:Cohort study.Methods:Fourteen baseball players (age, 16 ± 2 years) attended 3 supervised training sessions per week for 20 weeks. Strengthening of the upper extremity was performed with a specific progression that utilized readily available equipment. Testing was completed at baseline and at 4, 8, and 20 weeks. The posterior shoulder endurance test was performed to assess muscular endurance. Glenohumeral internal and external rotation range of motion and strength were measured.Results:Posterior shoulder endurance improved from 30 ± 14 repetitions at baseline to 66 ± 26 at 4 weeks and 88 ± 36 at 20 weeks (P < 0.05). Glenohumeral internal rotation range of motion and the glenohumeral internal/external rotation strength ratio remained similar over the course of the program.Conclusion:Implementation of a preseason training program effectively increased shoulder muscular endurance while maintaining strength ratios and range of motion throughout the 20-week program.Clinical Relevance:This program improved a key parameter known to be associated with shoulder function and injury risk. This study describes a simple clinical tool to assess muscular endurance of the posterior shoulder.

Measurements for posterior shoulder tightness: reliability without validity

This article was the fi rst to describe the loss of glenohumeral internal rotation range of motion (ROM) in pitchers, and the authors report using glenohumeral horizontal adduction with the humerus in neutral internal/external rotation to assess posterior shoulder tightness. In the 26 years since this publication, posterior shoulder tightness has regularly been examined for its role in shoulder pathology, especially in overhead athletes. Whenever a clinical measurement is taken, two critical properties of that measurement should be known: validity and reliability. The current paper has compiled a summary of many previous studies that have examined these constructs as they relate to measuring posterior shoulder tightness. What becomes apparent through this summary is that the reliability of current clinical measurements is fairly strong, especially when the measurement method appears to be well-defined, tightly controlled, and repeated within a short time interval by experienced raters. What is also apparent in the summary is that the validity of measuring posterior shoulder tightness is not only considered modest at best, but arguably, has not been established.

Stretching the Posterior Shoulder Structures in Subjects with Internal Rotation Deficit: Comparison of Two Stretching Techniques

Background Glenohumeral internal rotation deficit (GIRD) and posterior shoulder stiffness have been associated with impingement symptoms in the overhead athlete. Stretching of the posterior shoulder is advised in injury prevention as well as rehabilitation programs. The purpose of the present study was to determine if stretching of the posterior shoulder improves ROM and reduces symptoms, and to compare angular with non-angular stretching techniques. Methods 60 overhead athletes with GIRD (age 25 ± 7.2 years, height 176 ± 8 cm, weight 69.8 ± 10.2 kg) participated to the study. Thirty athletes had no shoulder pain, 30 had impingement symptoms on the dominant shoulder. The subjects were randomly assigned into an “angular” or a “non-angular” treatment group. They were treated for 3 weeks (9 sessions) and followed for another period of 3 weeks after completion of the treatment. Treatment outcome variables were glenohumeral internal rotation range of motion, and, in the patient group, pain (VAS) scores and functional performance (ROWE-score). Results Statistical analysis showed a significant increase in ROM ( p &lt; .05) in both treatment groups, in the patient as well as in the healthy control group. In addition, patients showed a significant improvement in pain assessment scores, and a significant increase in the Modified Rowe Score. There were no significant differences between both treatment techniques. Discussion Stretching, angular as well as non-angular techniques, increases internal rotation ROM in overhead athletes, and may decrease sport specific shoulder pain in overhead athletes with impingement symptoms.

Glenohumeral Internal Rotation Measurements Differ Depending on Stabilization Techniques

Background:The loss of glenohumeral internal rotation range of motion in overhead athletes has been well documented in the literature. Several different methods of assessing this measurement have been described, making comparison between the results of studies difficult.Hypothesis:Significant differences in the amount of internal rotation range of motion exist when using different methods of stabilization.Study Design:Descriptive laboratory study.Methods:Three techniques were used bilaterally in random fashion to measure glenohumeral internal rotation range of motion: stabilization of the humeral head, stabilization of the scapula, and visual inspection without stabilization. An initial study on 20 asymptomatic participants was performed to determine the intrarater and interrater reliability for each measurement technique. Once complete, measurements were performed on 39 asymptomatic professional baseball players to determine if a difference existed in measurement techniques and if there was a significant side-to-side difference. A 2-way repeated-measures analysis of variance was used.Results:While interrater reliability was fair between all 3 methods, scapular stabilization provided the best intrarater reliability. A statistically significant difference was observed between all 3 methods (P < .001). Internal rotation was significantly less in the dominant shoulder than in the nondominant shoulder (P < .001).Conclusion:Differences in internal rotation range of motion measurements exist when using different methods. The scapula stabilization method displayed the highest intrarater reproducibility and should be considered when evaluating internal rotation passive range of motion of the glenohumeral joint.Clinical Relevance:A standardized method of measuring internal rotation range of motion is required to accurately compare physical examinations of patients. The authors recommend the use of the scapula stabilization method to assess internal rotation range of motion by allowing normal glenohumeral arthrokinematics while stabilizing the scapulothoracic articulation.

Scapular Angular Positioning at End Range Internal Rotation in Cases of Glenohumeral Internal Rotation Deficit

Controlled laboratory study. Investigate the relationship between glenohumeral internal rotation range-of-motion deficit and 3-dimensional scapular angular positioning during active arm movements in participants with recent participation in overhead sports activity. Subacromial impingement is one of the most common shoulder pathologies and is multifactorial in etiology. Posterior glenohumeral joint capsule tightness has been theorized to contribute to one potential causal factor: abnormal scapular positioning. Twenty-three subjects, who had participated in competitive sports involving overhead activity within the last 5 years, were categorized into 2 groups based on the degree of glenohumeral internal rotation deficit (20% deficit threshold). Scapular angular positioning of subjects performing shoulder internal rotation from 90 degrees flexion and abduction shoulder positions was evaluated using 3-dimensional electromagnetic surface tracking. Additional sensors monitored trunk and humeral motion. Scapular position data at end range glenohumeral internal rotation, along with glenohumeral internal rotation range of motion measurements, were used to analyze the relationship between glenohumeral internal rotation deficit and scapular position using 2-way ANOVA and regression analyses. The internal rotation deficit group had significantly greater scapular anterior tilt (9.2 degrees difference, P = .04) across positions, as compared to the control group. Regression analysis demonstrated a significant association between glenohumeral internal rotation deficit and scapular position (tilting) during flexed internal rotation (r(2) = 0.37, P = .03) and for scapular position (anterior tilting and upward rotation) during abducted internal rotation (r = 0.35, P = .036). These findings demonstrate a significant relationship between glenohumeral internal rotation deficit and abnormal scapular positioning, particularly increased anterior tilt. This relationship identifies a possible mechanism for development of excessive scapular anterior tilt.