Shoulder External Rotation Research Articles

Isokinetic profile of elbow and shoulder muscle strength of seated throwers

Throwing events such as discus, shot put, and javelin involve repetitive and explosive overhead activities in a short period, which increases the risk of upper extremity injuries. Furthermore, the available data on seated throwers are inadequately documented. Thus, this study aims to (1) describe the muscle strength profiles of shoulder external and internal rotators and the elbow flexors and extensors in seated throwers, and (2) identify the differences in muscle strength between seated throwers competing at international levels and those at national levels. Twenty-one seated throwers participated in this study, including twelve at the international level and nine at the national level. We conducted isokinetic shoulder strength tests for shoulder internal rotation (IR), shoulder external rotation (ER), elbow flexion (EF), and elbow extension (EE) on the dominant side of the para-athletes using a Biodex isokinetic dynamometer at speeds of 60°/s and 300°/s. An independent t-test was utilized to assess the differences between international and national-level para-athletes. Except for total work (TW) at 60°/s and average power (AP) at 300°/s, the IR variables of the international group were significantly higher than those of the national group (p < 0.001). Additionally, some EF variables of the international group, including peak torque (PT) and TW at 60°/s, and PT, AP, and TW at 300°/s, were higher than those of the national group (p < 0.05, p < 0.01). The findings of this study are important for developing training programs, enhancing performance, and preventing injuries among seated throwers.

A dataset for fatigue estimation during shoulder internal and external rotation movements using wearables

Wearable sensors have recently been extensively used in sports science, physical rehabilitation, and industry providing feedback on physical fatigue. Information obtained from wearable sensors can be analyzed by predictive analytics methods, such as machine learning algorithms, to determine fatigue during shoulder joint movements, which have complex biomechanics. The presented dataset aims to provide data collected via wearable sensors during a fatigue protocol involving dynamic shoulder internal rotation (IR) and external rotation (ER) movements. Thirty-four healthy subjects performed shoulder IR and ER movements with different percentages of maximal voluntary isometric contraction (MVIC) force until they reached the maximal exertion. The dataset includes demographic information, anthropometric measurements, MVIC force measurements, and digital data captured via surface electromyography, inertial measurement unit, and photoplethysmography, as well as self-reported assessments using the Borg rating scale of perceived exertion and the Karolinska sleepiness scale. This comprehensive dataset provides valuable insights into physical fatigue assessment, allowing the development of fatigue detection/prediction algorithms and the study of human biomechanical characteristics during shoulder movements within a fatigue protocol.

Exploring the interplay of trunk and shoulder rotation strength: a cross-sport analysis.

Introduction: Trunk and shoulder strength are consistently shown to be involved in performance limitations, as well as contributing to stability, power output, and reducing the risk of injury. Although their biomechanical interaction is a critical aspect for athletes, there is limited research on the relationship between trunk and shoulder strength in sports where upper body mechanics are critical for optimal performance. Purpose: This study examined the differences and relationships between trunk rotational strength and shoulder rotational strength among athletes participating in mixed martial arts (MMA), tennis, swimming, and baseball. Methods: Maximal voluntary contraction tests were performed to evaluate strength of 39 professional adult male athletes from disciplines of MMA (n = 6), tennis (n = 11), swimming (n = 11) and baseball (n = 11). Peak force data were used in sports comparison and relationship analysis between trunk and shoulder rotation strength parameters. Results: The findings revealed a complex and significant relationship between trunk and shoulder strength, with unique patterns for each athletic discipline. Tennis players exhibited a strong correlation between trunk bilateral differences and internal shoulder rotation, while other disciplines demonstrated a more balanced use of trunk asymmetry. Swimmers displayed the best interactions between trunk and shoulder overall, emphasizing the aquatic environment's biomechanical demands. In MMA, the strongest correlation was between shoulder internal and external rotation with the trunk, mainly due to the number of defensive movements in addition to offensive ones. Baseball pitchers showed a significant correlation between internal/external shoulder rotation strength ratio and trunk asymmetry. Conclusion: While no differences in peak force variables were found, unique relationships between trunk and shoulder rotational performance were discovered. The results suggest a long-term sport-specific adaptation of the trunk-shoulder interaction in sports that require upper limb power movements. It seems, that the relationship between the various parameters of trunk and shoulder was influenced by the movement stereotype of each sport. Therefore, recognition of sport-specific interactions is critical to the development of effective training programs that enhance performance and potentially reduce injury risk in different sports. Researchers and practitioners should focus on longitudinally monitoring fluctuations in TRS and SRS relationships throughout each sport season and examining potential associations with injury incidence.

Altered Cervical Spine Position Results in Decreased Eccentric Shoulder Rotation Strength.

Overhead athletes require strenuous shoulder activity in nonneutral cervical spine positions to eccentrically decelerate the throwing/striking arm following ball release/contact. We therefore aimed to compare eccentric shoulder rotation strength through a 90° arc between neutral and rotated positions. Fifty-two participants (19 M, 34 F 170±10 cm; 73±18 kg, 21.9±2.9 years) without shoulder or cervical spine pathology participated. Isokinetic eccentric shoulder rotation strength was measured through a 90° arc with the shoulder elevated 90° in frontal plane (frontal plane), and 45° anterior to the frontal plane (scapular plane) in neutral and rotated cervical spine positions. Cervical spine position was obtained by instructing participants to maximally rotate their respective side. Frontal plane eccentric external rotated strength differed between neutral and contralaterally positions in the first 10° of the motion, near forearm vertical (p+=+0.029). Internal rotation strength differed between neutral and contralaterally rotated positions from 55-60° external rotation (p+=+0.004). Scapular plane eccentric external rotation differed between cervical positions between 21-67° shoulder external rotation (p<0.001). Scapular plane internal rotation strength differed between cervical positions between 22-60° shoulder external rotation (p<0.001). In populations requiring strenuous use of their shoulders in altered cervical spine positions, sports medicine clinicians should consider including strength testing that reflects the functional positions of their patients during an orthopedic examination.

Injury and Biological Factors Impact Shoulder Function following Autogenous Grafting of Spinal Nerves for Pan-Brachial Plexus Reconstruction.

Shoulder function following spinal nerve grafting in pan-brachial plexus injuries(Pan-BPI) is not well described. The purpose of this study was twofold: 1)to evaluate shoulder abduction(ABD) and external rotation(ER) after grafting of viable spinal nerves to the suprascapular nerve(SSN), axillary nerve(AxN), or posterior division of the upper trunk(PDUT); and 2)to determine patient characteristics, injury severity/characteristics, and nerve graft factors that influenced outcomes. 362 Pan-BPI reconstruction patients from a single institution were reviewed for those who underwent spinal nerve grafting for shoulder reanimation between 2001 and 2018. Patient demographics, injury severity scores(ISS), graft characteristics, strength, range of motion for shoulder ABD and ER, and patient-reported outcomes were recorded. Patients were divided into three groups based on the recovery of shoulder function: no return, ABD only, and ABD and ER. 110 patients underwent spinal nerve grafting, with 41 meeting inclusion criteria. 17(41.5%) had no return of shoulder function, 14(34.1%) had ABD alone, and 10(24.4%) had ABD and ER. Patients with recovery of both ABD and ER were significantly younger(18.6±5.56), had lower BMI(22.4±4.0), and lower ISS(10.5±6.24, p=0.003). Multivariable analysis found that with increasing age(OR:0.786, 95%CI:0.576,0.941) and ISS(OR:0.820, 95%CI:0.606-0.979), odds for return of ABD and ER significantly decreased. In Pan-BPI, 24.4% of patients demonstrated return of both ABD and ER following spinal nerve grafting to SSN and either AxN or PDUT. Age, BMI, and ISS were associated with poorer recovery of shoulder function. Careful patient selection and consideration of age, BMI, and ISS may improve outcomes of spinal nerve grafting for shoulder reanimation. III.

Effects of Eccentric Versus Concentric Strengthening in Patients With Subacromial Pain Syndrome: A Randomized Controlled Trial.

Subacromial pain syndrome (SPS) is the most common cause of shoulder pain. Therapeutic exercise is the first-line treatment for SPS; however, the ideal exercise type remains unclear. Here, we compared the effects of eccentric and concentric strengthening in patients with SPS. Adding isolated eccentric strengthening to a multimodal physiotherapy program (MPP) would lead to greater improvements in outcomes compared with either MPP alone or adding isolated concentric strengthening to the MPP. Randomized controlled trial. Level 2. A total of 45 patients were randomized to eccentric strengthening (ESG), concentric strengthening (CSG), and control (CG) groups; all groups received the MPP. The strengthening groups also performed group-specific strengthening. Shoulder pain, abduction and external rotation (ER) strength, joint position sense (JPS), the Constant-Murley Score (CMS), and the Disabilities of the Arm, Shoulder and Hand score were collected at baseline, after 12 weeks of treatment, and at week 24. For CMS, ESG exhibited a greater, but not clinically meaningful, improvement than CSG and CG (P < 0.05). Eccentric abduction strength increased in ESG compared with CG. From baseline to follow-up, abduction strength increased in ESG compared with CSG and CG. Eccentric abduction strength increased in CSG compared with CG. JPS at abduction improved in the ESG compared with CG. Other between-group comparisons were not significant (P > 0.05). In SPS, eccentric strengthening provided added benefits, improving shoulder abduction strength and JPS at abduction, and was superior to concentric strengthening for improving shoulder abduction strength. Neither strengthening approach had an additional effect on shoulder function, pain, ER strength, or rotational JPS. Clinicians could implement eccentric strengthening as a motor control retraining for strength and proprioception gain rather than for pain relief and reducing disability.

Is the correlation of the core muscle performance with shoulder pain and function altered by scapular dyskinesis in subjects with shoulder pain?

BACKGROUND: Daily activities that involve upper limb movements require muscle activation from different body parts by transferring forces and energy along the functional kinetic chain. The scapulae connect and transfer forces between the trunk and the upper limbs, so scapular dyskinesis may compromise the performance of the kinetic chain. OBJECTIVE: To assess the relationship between core muscle performance and shoulder pain and function in individuals with shoulder pain, with and without scapular dyskinesis. METHODS: Data was collected from 77 non-athlete adults aged between 18 and 50 years with shoulder pain, 45 had scapular dyskinesis. Core muscle performance was measured using the prone bridging test (PBT). Shoulder pain and disability were measured by the Shoulder Pain and Disability Index (SPADI), and the upper limbs’ stability was assessed by the Closed Kinetic Chain Upper Extremity Stability Test (CKCUEST). The peak torque of shoulder external and internal rotators was measured using an isokinetic dynamometer. Multiple linear regression models evaluated the relationship between the PBT and CKCUEST, SPADI, and shoulder rotator strength. RESULTS: Significant correlations were found between the PBT and the SPADI total score (r = – 0.522), pain domain (r = – 0.513), and disability domain (r = – 0.501); normalized score (r = 0.593), and the power (r = 0.624) of the CKCUEST; and peak torque for external (r = 0.256) and internal (r = 0.292) rotations. Scapular dyskinesis did not influence the magnitude of the correlations and predictive values. CONCLUSION: The PBT was correlated with shoulder pain and function, but scapular dyskinesis did not affect the magnitude of these relationships.

Factors determining the short-term clinical outcomes of conservative treatment in patients with supraspinatus tear

IntroductionTo identify factors influencing the better and worse changes in the Western Ontario Rotator Cuff Index of patients undergoing conservative treatment for supraspinatus tendon tear. MethodsThe study included 30 patients with supraspinatus tendon tear who underwent conservative treatment. The average duration of intervention was 35.4 days. The Western Ontario Rotator Cuff Index, shoulder range of motion, isometric muscle strength, supraspinatus tendon thickness, thickness of the supraspinatus, infraspinatus, and teres minor muscles, and acromiohumeral interval were assessed before and after the intervention. In the statistical analyses, change in the Western Ontario Rotator Cuff Index was the dependent variable, and the amount of change in each measurement variable before and after the intervention was the independent variable. ResultsThe average Western Ontario Rotator Cuff Index improved from 1067 at pre-treatment to 997 at post-treatment, but without a significant difference (p = 0.29). A multiple regression analysis revealed that supraspinatus tendon thickness and muscle strength in shoulder external rotation at 90° scaption had a significant effect on the change in the Western Ontario Rotator Cuff Index (R2 = 0.44, p < 0.01). ConclusionSupraspinatus tendon thickness and muscle strength in shoulder external rotation at 90° scaption were important factors for the Western Ontario Rotator Cuff Index score in the early stages of conservative treatment for patients with supraspinatus tendon tear.

Variability between Different Hand-Held Dynamometers for Measuring Muscle Strength.

Muscle strength is routinely measured in patients with neuromuscular disorders by hand-held dynamometry incorporating a wireless load cell to evaluate disease severity and therapeutic efficacy, with magnitude of effect often based on normative reference values. While several hand-held dynamometers exist, their interchangeability is unknown which limits the utility of normative data. We investigated the variability between six commercially available dynamometers for measuring the isometric muscle strength of four muscle groups in thirty healthy individuals. Following electro-mechanical sensor calibration against knowns loads, Citec, Nicholas, MicroFET2, and Commander dynamometers were used to assess the strength of ankle dorsiflexors, hip internal rotators, and shoulder external rotators. Citec, Jamar Plus, and Baseline Hydraulic dynamometers were used to capture hand grip strength. Variability between dynamometers was represented as percent differences and statistical significance was calculated with one-way repeated measures ANOVA. Percent differences between dynamometers ranged from 0.2% to 16%. No significant differences were recorded between the Citec, Nicholas, and MicroFET2 dynamometers (p > 0.05). Citec grip strength measures differed to the Jamar Plus and Baseline Hydraulic dynamometers (p < 0.01). However, when controlling for grip circumference, they were comparable (p > 0.05). Several hand-held dynamometers can be used interchangeably to measure upper and lower limb strength, thereby maximising the use of normative reference values.

Stratification of the minimal clinically important difference, substantial clinical benefit, and patient acceptable symptomatic state after total shoulder arthroplasty by implant type, preoperative diagnosis, and sex

Clinical significance, as opposed to statistical significance, has increasingly been utilized to evaluate outcomes after total shoulder arthroplasty (TSA). The purpose of this study was to identify thresholds of the minimal clinically important difference (MCID), substantial clinical benefit (SCB), and patient acceptable symptomatic state (PASS) for TSA outcome metrics and determine if these thresholds are influenced by prosthesis type (anatomic or reverse TSA), sex, or preoperative diagnosis. A prospectively collected international multicenter database inclusive of 38 surgeons was queried for patients receiving a primary aTSA or rTSA between 2003 and 2021. Prospectively, outcome metrics including ASES, shoulder function score (SFS), SST, UCLA, Constant, VAS Pain, shoulder arthroplasty smart (SAS) score, forward flexion, abduction, external rotation, and internal rotation was recorded preoperatively and at each follow-up. A patient satisfaction question was administered at each follow-up. Anchor-based MCID, SCB, and PASS were calculated as defined previously overall and according to implant type, preoperative diagnosis, and sex. The percentage of patients achieving thresholds was also quantified. A total of 5851 total shoulder arthroplasties (TSAs) including aTSA (n=2236) and rTSA (n=3615) were included in the study cohort. The following were identified as MCID thresholds for the overall (aTSA+rTSA irrespective of diagnosis or sex) cohort: VAS Pain (-1.5), SFS (1.2), SST (2.1), Constant (7.2), ASES (13.9), UCLA (8.2), SPADI (-21.5), and SAS (7.3), Abduction (13°), Forward elevation (16°), External rotation (4°), Internal rotation score (0.2). SCB thresholds for the overall cohort were: VAS Pain (-3.3), SFS (2.9), SST 3.8), Constant (18.9), ASES (33.1), UCLA (12.3), SPADI (-44.7), and SAS (18.2), Abduction (30°), Forward elevation (31°), External rotation (12°), Internal rotation score (0.9). PASS thresholds for the overall cohort were: VAS Pain (0.8), SFS (7.3), SST (9.2), Constant (64.2), ASES (79.5), UCLA (29.5), SPADI (24.7), and SAS (72.5), Abduction (104°), Forward elevation (130°), External rotation (30°), Internal rotation score (3.2). MCID, SCB, and PASS thresholds varied depending on preoperative diagnosis and sex. MCID, SCB, and PASS thresholds vary depending on implant type, preoperative diagnosis, and sex. A comprehensive understanding of these differences as well as identification of clinically relevant thresholds for legacy and novel metrics is essential to assist surgeons in evaluating their patient's outcomes, interpreting the literature, and counseling their patients preoperatively regarding expectations for improvement. Given that PASS thresholds are fragile and vary greatly depending on cohort variability, caution should be exercised in conflating them across different studies.

A 6-week randomized-controlled field study: effect of isokinetic eccentric resistance training on strength, flexibility and muscle structure of the shoulder external rotators in male junior handball players.

Background: Team handball involves a tremendous amount of shoulder motion with high forces during repeated extended external range of motion. This causes shoulder complaints and overuse injuries. While eccentric training for the lower extremity shows preventive effects by improving strength, range of motion and fascicle length, there is a research gap for the shoulder joint and for advanced tissue characterization using diffusion tensor imaging. Objectives: To investigate the effects of 6-week eccentric isokinetic resistance training on strength, flexibility, and fiber architecture characteristics of the external rotators compared to an active control group in junior male handball players. Methods: 15 subjects were randomly assigned to the eccentric training group and 14 subjects to the active control group (conventional preventive training). Primary outcome measures were eccentric and concentric isokinetic strength of the external rotators, range of motion, and muscle fascicle length and fascicle volume. Results: The intervention group, showed significant changes in eccentric strength (+15%). The supraspinatus and infraspinatus muscles showed significant increases in fascicle length (+13% and +8%), and in fractional anisotropy (+9% and +6%), which were significantly different from the control group. Conclusion: Eccentric isokinetic training has a significant effect on the function and macroscopic structure of the shoulder external rotators in male junior handball players. While strength parameters and muscle structure improved, range of motion did not change. This research helps understanding the physiology of muscle and the role of eccentric training on shoulder function and muscle structure. Furthermore, DTI was found to be a promising tool for advanced tissue characterization, and the in vivo derived data can also serve as model input variables and as a possibility to extend existing ex-vivo muscle models. Future research is needed for functional and structural changes following convenient eccentric field exercises.

Limited total arc range of motion increases sheer stress in the shoulder while pitching in collegiate baseball pitchers.

Upper extremity injuries in baseball pitchers cause significant time-loss from competing and decreased quality of life. Although shoulder range of motion (ROM) is reported as a key factor to prevent potential injury, it remains unclear how limited glenohumeral ROM affects pitching biomechanics which may contribute to upper extremity injuries. To investigate how pitchers with decreased total arc glenohumeral ROM of the throwing arm differed in upper extremity pitching kinematics and kinetics as well as ball velocity compared to pitchers with greater levels of glenohumeral ROM. Cross-sectional Study. Laboratory. Fifty-seven baseball pitchers (ages 18-24) were divided into either control (≧160° total arc) or lower ROM (<160° total arc) groups. The mean glenohumeral ROM deficits, pitching kinematic and kinetic outcomes, and ball velocity were compared between groups. The control group demonstrated significantly less deficit in total arc ROM between arms than the lower ROM (Control: -1.5±10.0°, Lower ROM: -12.4±13.9°, p<.001). While, the lower ROM group displayed less maximal shoulder external rotation (ER) while pitching, the control group had significantly less difference in ROM between maximal shoulder ER while pitching and clinically-measured ER (Lower ROM: 64.4±12.1°, Control: 55.8±16.6°, p=.025). The control group had significantly faster ball velocity compared to the lower ROM group (Control: 85.0 ± 4.3mph, Lower ROM: 82.4 ± 4.8mph, p=.024). Pitchers with decreased total arc glenohumeral ROM (<160° total arc) may undergo over-stretching toward ER in the shoulder during the late cocking phase. Pitchers with higher total arc ROM can pitch the same or faster ball without increasing loading in the upper extremity. Total arc glenohumeral ROM measurement can be a clinical screening tool to monitor shoulder condition over the time, and pitchers with limited total arc ROM might be at higher risk of shoulder injury.

Short-term effects of a new resistance exercise approach on physical function during chemotherapy after radical breast cancer surgery: a randomized controlled trial

BackgroundApproximately 30% of post-operative breast cancer patients develop shoulder joint movement disorders affecting routine upper limb movement. This study discusses the impact of a neuromuscular joint facilitation (NJF) method on the physical function of breast cancer patients experiencing shoulder dysfunction during chemotherapy after radical surgery.MethodsThis study included 162 female patients who have unilateral breast cancer in a cancer hospital in China. They developed shoulder joint mobility disorders during chemotherapy within 1–3 months postoperatively. These patients were divided into three groups: NJF, conventional rehabilitation (conventional group), and control groups. The clinical examination included the maximum passive and active range of motion (ROM) of the shoulder (flexion, extension, abduction, adduction, and external and internal rotation). Other evaluations included a pain score using a visual analog scale (VAS), grip strength, and supraspinatus muscle thickness. All tests were evaluated pre-and post-intervention.ResultsThe NJF group showed a significant increase in all shoulder ROM angles post-intervention. In the conventional group, all other ROM values increased significantly, except passive external rotation ROM. In the control group, all other ROM values increased significantly, except passive and active external rotation ROM. All three groups had decreased VAS scores, increased grip strength, and supraspinatus muscle thickness post-intervention during active abduction. In the control group, the supraspinatus contraction rate decreased significantly at 60° and 90° abduction post-intervention compared to that at pre-intervention.ConclusionThis study revealed that NJF during chemotherapy had positive clinical intervention effects, improving shoulder joint mobility disorders, pain, grip strength, and external rotation following radical breast cancer surgery.Clinical trial registrationChinese Clinical Trial Registry; https://www.chictr.org.cn/ (ChiCTR2300073170), registered (03/07/2023).

Exercises with the StretchPole improve shoulder joint range of motion

The ‘StretchPole’ foam roller product is mainly used to loosen muscle groups and joints in the deeper layers of the body that are normally inaccessible to the human hand, and to realign the skeletal structure by lying on the pole and performing exercises. It is also used to strengthen the core, which plays an important role in postural maintenance and stability. The purpose of this study was to determine the effects of the ‘Solacon’ exercise routine using a StretchPole on shoulder joint range of motion. Forty healthy participants performed Solacon exercises using a StretchPole. The specific method of Solacon comprises six movements: (1) chest slide, (2) crescent, (3) cone, (4) twister, (5) shoulder alternating rotation, and (6) chin-in exercise. The joint range of motion of the bilateral shoulder joint flexion, abduction, horizontal abduction, and external rotation (1st and 2nd) were measured before and after the exercises. All measures were significantly higher after exercise compared to before exercise. Solacon exercises improve thoracic spine and scapular mobility and stretch the anterior thoracic muscle groups. The shoulder joint in the broad sense consists of the humerus, scapula, clavicle, sternum, and ribs. These in turn constitute the scapulohumeral joint, acromioclavicular joint, sternoclavicular joint, scapulothoracic joint and functional second shoulder joint. In addition, costovertebral joints and intervertebral joints are also involved because of the added motion of the ribs and the spine. We considered that the ranges of motion of shoulder joint flexion, abduction, horizontal abduction, and external rotation measured in this study were expanded.

Role of ultrasound guided suprascapular nerve block aided mobilization physiotherapy in frozen shoulder recovery: a prospective study

Background: Frozen shoulder is debilitating condition marked by progressive shoulder pain and restricted mobility, affecting sleep and activities of daily living of a person. The objective of this study was to evaluate the efficacy of USG guided suprascapular nerve block aided mobilization physiotherapy for management of frozen shoulder so as to improve the quality of living of patients. Methods: This prospective interventional study was conducted at the Department of Orthopaedics of a teaching institute of Central India from January 2021 to April 2023 after obtaining ethical clearance. Patients diagnosed with frozen shoulder and giving written consent were included in this study after considering the inclusion and exclusion criteria. Baseline demographics, symptom duration, degree of active and passive shoulder range of movement, Shoulder pain and disability index (SPADI) score were documented on day of presentation (preintervention) after which USG guided suprascapular nerve block was given. Post SSNB, 10 sessions of supervised mobilization physiotherapy was given. SPADI scores and degree of active and passive range of movement were noted at 3rd, 6th and 12th week and compared using statistical tests namely repeated measure ANOVA and chi square test of independence. Results: A total of 54 patients enrolled in the study after meeting inclusion criteria, only 46 completed the follow up and their mean SPADI pain score and mean SPADI disability score at presentation significantly reduced at 12 weeks post intervention. Range of flexion, abduction and external rotation of shoulder also showed significant increase (p value&lt;0.05). Number of participants with severe restriction of shoulder internal rotation also decreased after SSNB aided physiotherapy. Conclusions: USG guided suprascapular nerve block aided physiotherapy exercise schedule is a safe and effective outpatient treatment for frozen shoulder providing early pain relief and improving shoulder mobility.

Quantitative evaluation of adhesion severity around subscapularis and its relationship with shoulder range of motion in frozen shoulder and rotator cuff disorder: an observational study using dynamic ultrasonography

BackgroundThis study aimed to evaluate the severity of adhesion between muscles in the shoulder joint using dynamic ultrasonography and to confirm whether adhesions cause range of motion (ROM) restrictions. MethodsTwenty-four shoulders from fifteen frozen shoulder (FS) patients and Twenty-four shoulders from eighteen rotator cuff disorder (RCD) patients were enrolled. We obtained ultrasound video sequences of the subscapularis and deltoid muscles during shoulder external rotation. The mean stretching velocities of the deltoid (VDelt) and subscapularis (VSSC) were subsequently analyzed using a PC. If adhesions occurred between both muscles, the deltoid was stretched more vigorously, and we calculated VDelt/VSSC as adhesion severity. The coracohumeral ligament (CHL) thickness was measured using the same images. Shoulder ROM was measured by using a universal goniometer. ResultsThe intraclass correlation coefficients (1.1) and (2.1) of the adhesion severity measurements were 0.85 and 0.91, respectively. Multiple linear regression analysis revealed that the adhesion severity is a significant predictor for external rotation ROM in the RCD group (R2 = 0.44, F = 10.1, p < 0.01, t = -2.9), while CHL thickness predicts ROM in the FS group (R2 = 0.28, F = 5.5, p = 0.01, t = -3.0). ConclusionThe proposed method is reliable. Muscle adhesion causes ROM restriction of the shoulder joint. The primary cause of shoulder ROM restriction differed between the diagnostic groups.

Upper Extremity Musculoskeletal Profiles in Tennis Players: A Systematic Review.

Tennis-specific musculoskeletal (MSK) screening can assess range of motion (ROM) and muscular imbalances. Identifying normative values before implementing a MSK screen is essential in contributing to athlete performance and injury risk profiles. To review upper extremity MSK data in healthy tennis players across age, sex, and level of play. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed for this review. A search was conducted in MEDLINE, SPORTDiscus, Embase, and CINAHL. This review included shoulder, elbow, and wrist ROM, isometric strength, or isokinetic strength in a tennis population. Each article was critically appraised to help identify the internal and external validity of each study. Systematic review. Level 3. A total of 41 studies met the search criteria. Each contributor organized the data elements of interest into data tables, with a second contributor assigned for review. Data elements of interest included player and study characteristics: ROM, isometric dynamometry, and isokinetic strength. A total of 3174 players were included in the final studies. Most of the players included were competitive adolescents and young adults; 15 studies included ROM data. Male tennis players consistently had more external rotation (ER) gain (range, 1.8º to 8.8º) and internal rotation (IR) loss (range, -15.3º to -3.0º) when compared with their female counterparts (ER range, -2.5º to 5.8º; IR range, -10.4º to -3º). Shoulder IR and ER strength were measured in the majority of all the strength studies, with the external rotators generating at least two-thirds the strength of the internal rotators. Overall MSK data of tennis players indicate that shoulder strength values are often larger than nontennis players, but equal to or slightly lower than comparable athletes in other overhead sports. Adaptive changes of the glenohumeral joint and subsequent rotational motion are similar to those of other overhead athletes.

The COVID-19 lockdown as a model of detraining in division 1 college softball players

BackgroundThe COVID-19 pandemic interrupted the organized training of softball players, similar to the abrupt cessation of sports participation that can happen after an injury. Thus, the COVID-19 pandemic offers a unique model to study how sudden detraining influences softball players.MethodsWe recruited a sample of convenience of National Collegiate Athletic Association Division 1 softball players. They participated in three data collections: pre-lockdown (Jan 2020, T1), post-lockdown (Sept 2020, T2), and before the 2021 season (Jan 2021, T3). Between T1 and T2, players received an at-home conditioning and throwing program, but compliance was not strictly monitored. Between T2-T3, players resumed formal fall training (team-organized workouts, on-field practice, and within-team scrimmage games). At each time point, we collected bilaterally: 1) shoulder internal rotation (IR) and external rotation (ER) range of motion (ROM); 2) shoulder IR and ER strength; 3) hip IR and ER ROM; and 4) hip abduction and extension strength. We used four independent (2 Sides × 3 Timepoints) MANOVA with repeated measures; we followed up significant MANOVA main effect of time with Sidak posthoc tests for pairwise comparisons between time points.ResultsFifteen players participated in this study. We found a significant MANOVA main effect of time for shoulder and hip ROM (p < 0.01). Between T1-T2, dominant shoulder ER ROM decreased 6.5°, dominant shoulder IR ROM increased 4.3°, and lead hip IR ROM increased 4.4°. Between T2-T3, dominant shoulder ER ROM increased 6.3° and trail hip ER ROM increased 5.9°. We found a significant MANOVA main effect of time for shoulder strength (p = 0.03) but not for hip strength (p = 0.18). Between T2-T3, non-dominant shoulder IR and ER increased 1.8 kg and 1.5 kg, respectively.ConclusionA sudden and prolonged cessation of organized training generated changes in shoulder and hip ROM but affected strength to a lesser extent. The loss of shoulder ER and increased lead hip IR ROM are maladaptive as they are associated with injury in overhead athletes. Resuming team-organized training and scrimmage reversed some (shoulder ER), but not all of these changes. Practitioners should monitor clinical variables regularly and be aware of potential changes due to unexpected and prolonged interruptions in training, such as when players suffer sports-related injuries.

Shoulder rotator strength in judo athletes: A cross-sectional study with different experience levels

BACKGROUND: Judo practice requires high effort from athletes, mainly focused on the upper limbs, involving the shoulder complex. OBJECTIVE: To compare the shoulder internal (IR) and external (ER) rotation peak torque and conventional ratio (ER: IR) between judo athletes from different experience levels (novice vs. advanced) and to verify the distribution of athletes according to the ER: IR ratio classification. METHODS: Thirty-nine male judo athletes were divided into two groups (advanced: 20.5 ± 2.8 years and novice: 22.1 ± 5.5 years). The athletes performed a shoulder isokinetic protocol to measure IR and ER strength and the ER: IR ratio in novice and advanced groups. Chi-square tests were used to investigate the distribution of athletes according to the different groups of ER: IR ratio classification, and t-tests were used to compare the IR and ER peak torque and the ER: IR ratio between novice and advanced groups, with the level of significance set at 5%. RESULTS: The main results showed higher values of IR peak torque (77.3 ± 15.7 N⋅m in advanced vs. 48.2 ± 8.4 N⋅m in novices; p= 0.013), and a lower ER: IR conventional ratio in advanced athletes compared to novices (0.63 ± 0.1 advanced vs. 0.73± 0.2 in novice; p= 0.01). When individual values were analyzed, advanced athletes presented higher imbalance (&lt; 0.66 ER: IR ratio) than novices (p= 0.023). CONCLUSION: Advanced athletes presented higher shoulder IR peak torque, but higher imbalance in the ER: IR ratio than novices, probably because the long-term training induced an increase in IR strength without concomitant development in ER strength. Coaches and strength and conditioning trainers should monitor shoulder rotator strength in judo athletes to avoid muscle imbalances in this region, which is frequently employed in judo training routines.

Predicting pain and function with the neutrophil-to-lymphocyte ratio in patients following primary reverse total shoulder arthroplasty

BackgroundGlenohumeral joint osteoarthritis is prevalent in the middle-aged and elderly population, affecting approximately 16%-20% of individuals. Total shoulder arthroplasty has become a common treatment for osteoarthritis, with a notable rise in the use of reverse total shoulder arthroplasty (rTSA) over the past decade. Despite improvements in surgical technique and prostheses, 22% of patients continue to experience chronic pain following shoulder arthroplasty. Currently, medical practitioners lack a reliable method for identifying which patients will suffer from persistent pain and functional limitations after surgery. In this context, the neutrophil-to-lymphocyte ratio (NLR), known for measuring immune-inflammatory reactions and neuroendocrine stress, has gained significant attention. Therefore, the purpose of this study was to explore the predictive potential of the NLR in identifying patients who will experience elevated pain and functional limitations after primary rTSA. MethodsThis study was a retrospective cohort design. Patient data were collected retrospectively between 2019 and 2021 and grouped based on preoperative NLR (≥2.5 and <2.5). Primary outcome measures assessed were the American Shoulder and Elbow Surgeons (ASES) score, visual analog scale (VAS), Pittsburgh Sleep Quality Index, and Single Assessment Numeric Evaluation score. Secondary outcomes included active shoulder elevation and external rotation range of motion. Outcome measures were captured before surgery and at 6 and 12 months after surgery. ResultsAt 6 months following surgery, patients with an NLR ≥2.5 scored significantly worse on the VAS (P = .0171), ASES (P = .0015), and Single Assessment Numeric Evaluation (P = .0226). Differences in Pittsburgh Sleep Quality Index scores were not significant (P = .2705). Forward elevation and external rotation range of motion were similar between groups at 6 months (P = .7777 and P = .2630, respectively). There was no statistically significant difference between groups at 12 months across all variables. Multivariate analysis showed that an NLR <2.5 had a significant positive effect on the ASES score (P = .0011) at 6 months after adjusting for age, gender, body mass index, depression, low back pain, and diabetes. ConclusionsManagement of patients with chronic pain continues to be challenging with limited high-value interventions. Early identification of patients likely to have a protracted recovery following rTSA would allow for a multidisciplinary approach earlier in the recovery phase. Based on our results, patients who had a preoperative NLR value greater than 2.5 reported higher levels of pain, more functional limitations, and perceived poorer function at 6 months following rTSA. However, these effects were relatively small and not observed at the 12-month mark.