Shoulder Internal Rotation Strength Research Articles

Comparing the effectiveness of thrower’s specific exercise program with regular warm-up program in recreational cricket bowlers

INTRODUCTION: Thrower’s Ten program is a thrower-specific workout program that increases upper-extremity strength, power, and endurance, especially in overhead athletes. The study compares the thrower's ten-exercise program to the regular warm-up program in recreational cricket bowlers' posterior capsule tightness, internal rotator strength, upper extremity stability, and explosive power.
 METHODS: Based on inclusion and exclusion criteria, 82 recreational cricket bowlers were divided into experimental (n=41) and control (n=41) groups. The experimental group received Thrower's ten warm-up programs three times a week for six weeks, along with the standard warm-up. Control maintained its warm-up routine. Before and after six weeks, participants were tested for shoulder internal rotator strength, posterior capsule tightness, stability, and explosive power. SPSS software was used to calculate outcome measures mean, standard deviation, independent t-test, and paired t-test.
 RESULTS: After six weeks, all outcome measures exhibited a significant difference (p<0.05) within the experimental group, whereas none of the outcome measures depicted a significant difference (p>0.05) within the control group. A significant difference (p<0.05) was seen between the groups for post-test strength and upper extremity stability measures. However, a non-significant difference (p>0.05) was noted between groups for posterior capsule tightness and upper extremity explosive power.
 CONCLUSION: Compared to the usual warm-up program used by recreational cricket bowlers, the thrower’s customized warm-up routine is more successful in improving internal rotator strength and upper extremity stability. Both warm-up programs enhance posterior capsule tightness and upper extremity explosive power.

Relationship between strength training and shoulder pain in male and female water polo players.

The objective of this study was to assess the effect of two different strength-training methods on both male and female water polo players' performance and shoulder pain. The players were randomly allocated to a maximum strength (MS: 14 males, 8 females) or power strength (PS: 13 males, 8 females) training group. Before and after the intervention, we assessed player's anthropometric characteristics, shoulder internal and external rotation strength, hand grip strength, upper body strength, countermovement jump height, throwing velocity, swimming speed, shoulder pain on a visual analogue scale (VAS), wellness, and rate of perceived exertion per session. We observed no significant improvement (P<0.05) in specific skills but enhancement in hand grip strength in male players. In female players in the MS group, throwing speed and bench press weight decreased significantly (P<0.05). Shoulder external rotation strength at 240°/sec in male MS group players and shoulder external rotation strength at 60°/sec in female PS group players decreased significantly (P<0.05). In addition, from the first to the last week, shoulder pain increased significantly (P<0.05) in all players. Inverse correlations (P<0.05) were found between VAS and shoulder rotation strength in males in the PS group, and between wellness and shoulder internal rotation strength in men in the MS group and women in the PS group. We found that both MS and PS training did not enhance performance and increased shoulder pain in male and female water polo players.

Blood Flow Restriction Training in Patients With Rotator Cuff Tendinopathy: A Randomized, Assessor-Blinded, Controlled Trial.

To investigate the effects of low-load blood flow restriction (BFR) training on shoulder muscle thickness, rotator cuff (RC) strength, and shoulder symptoms in patients with RC tendinopathy. A randomized, assessor-blinded, controlled trial. Physiotherapy clinic at a university. Twenty-eight patients were randomized into an 8-week (2 times/week) shoulder rehabilitation, that is, BFR or non-BFR group. BFR training. (1) RC, deltoid, scapula retractor, and biceps muscle thicknesses and shoulder internal rotation (IR) and external rotation (ER) strengths. (2) Shoulder pain/function. The BFR group had a greater increase in biceps muscle thickness ( P = 0.002) and shoulder IR strength at 60 degrees/s ( P = 0.040) than the non-BFR group. No differences between the 2 groups were observed in other measurements. Significant improvements in supraspinatus, infraspinatus, and scapula retractor muscle thicknesses and in shoulder ER and IR strengths were observed over time in both the groups (all P < 0 .05). Also, shoulder pain decreased and shoulder function increased over time in both the groups (all P < 0 .05). Low-load BFR training resulted in a greater increase in biceps thickness and shoulder IR strength compared with the non-BFR group in patients with RC tendinopathy. However, there was no superiority of either exercise training regarding the RC, scapula retractor, deltoid muscle thicknesses, or improvements in shoulder ER strength and shoulder pain/function. The study was registered in ClinicalTrials.gov named Blood Flow Restriction Training in Patients with Shoulder Pain and the registration number is NCT04333784.

Relationships between isokinetic knee and shoulder peak strength with maximal punch force in boxing athletes

BACKGROUND: Muscle strength in the upper and lower limbs is a major contributing factor to punch force and is one of the keys to success in boxing. OBJECTIVE: This study aimed to investigate the relationship between knee and shoulder strength and punching force in boxers. METHODS: Twenty-one boxers completed knee flexion, knee extension, shoulder external rotation and internal rotation isokinetic concentric contractions at slow (60∘/s) and fast (180∘/s) angular velocities. Maximal punch force tests included lead and rear straight arm punching were assessed using a force platform. RESULTS: Pearson’s correlation coefficients revealed that knee extension (r= 0.646–0.848) and knee flexion (r= 0.470–0.646) peak torques were moderately to very strongly correlated with maximal punching force in lead and rear arms. The shoulder internal rotation (r= 0.492–0.634) and shoulder external rotation (r= 0.441–0.588) peak torques were moderate to strongly correlated with maximal punching force. Moreover, knee extension peak torques at 60∘/s had higher correlation with maximal punching force. In contrast, shoulder internal rotation peak torques at 180∘/s had a larger correlation with maximal punching force. CONCLUSIONS: The main findings indicated the importance of the capacity to generate maximum knee extension and rapid shoulder internal rotation strength, contributing to punch force production.

Comparison of shoulder functions between assembly workers with and without subacromial pain syndrome.

The occurrence of subacromial pain syndrome (SPS) is associated with the frequent handling and lifting of heavy loads and excessive repetitive work. Thus, assembly workers have a high prevalence of SPS. The purpose of this study was to investigate differences in shoulder ROM, muscle strength, asymmetry ratio, function, productivity, and depression between workers with and without SPS. Sixty-seven male workers (35 workers with SPS and 32 workers without SPS) participated in this study. Shoulder internal rotation (SIR), shoulder external rotation (SER), shoulder abduction (SAB), shoulder horizontal adduction ROM and SIR, SER, elbow flexion (EF), scapular depression and adduction, scapular protraction strength were measured. The asymmetry ratio was calculated using the asymmetry ratio formula; shoulder functions were measured using the shoulder pain and disability index (SPADI), disabilities of the arm, shoulder, and hand (DASH), and visual analogue scale (VAS); and Endicott work productivity scale (EWPS). The SPADI (p = 0.001), DASH (p = 0.001), and VAS (p = 0.001) values of workers with SPS were higher than those of workers without SPS. Also, workers with SPS had lower SIR (p = 0.001) and SAB (p = 0.002) ROM compared to workers without SPS. In addition, workers with SPS exhibited lower SIR (p = 0.012) strength than workers without SPS. Workers with SPS had higher asymmetry ratio in SIR (p = 0.015), SER (p = 0.005), and EF (p = 0.008) strength than workers without SPS. The SIR, SAB ROM, SIR strength, and the asymmetry ratio of SIR, SER, EF strengths could provide an important baseline comparison for the workers with SPS.

Strength after the arthroscopic Latarjet procedure: Are shoulder internal rotation, elbow flexion & supination strength decreased?

The Latarjet procedure is an effective shoulder stabilizing surgery, however, the procedure results in an alteration of anatomy that may result in shoulder and elbow weakness. Thus, the purpose of this study was to assess post-operative shoulder and elbow strength after the Latarjet procedure. We hypothesized that shoulder and elbow strength are not affected after the procedure. The study group consisted of patients that had undergone the arthroscopic Latarjet procedure. An isokinetic dynamometer was used to evaluate the strength of bilateral shoulder internal rotation, elbow flexion, forearm supination using peak torque (N/m), as well as grip strength (kilograms). Shoulder range of motion and the potential effects of hand dominance were further analysed. Nineteen patients with a mean age of 29 years and an average follow up of 47 months were included. Shoulder internal rotation strength, elbow flexion and forearm supination strength and grip strength were not significantly different when compared to the non-operative side (p > 0.13). The range of shoulder external rotation was significantly reduced (p < 0.001) on the Latarjet side. The results from this study demonstrate no statistically significant differences in the strength of shoulder internal rotation, elbow flexion, forearm supination or grip strength despite the surgical alterations to the subscapularis and conjoint tendon.

Exploration of the Shoulder Internal Rotation’s Influence on Throwing Velocity in Handball Players: A Pilot Study

The main objective of this study was to test the relationship between shoulder internal rotation strength and standing throwing velocity. A repeated measures cross-sectional study was conducted with 20 professional handball players (mean ± SD; age: 19.28 ± 2.55 years, weight: 81.52 ± 9.66 kg, height: 185 ± 6 cm, BMI: 23.74 ± 1.69). The participants were instructed to perform eight standing throws from the 7 m line of the handball court at maximum velocity to calculate the mean and maximum throwing velocity. An incremental test was performed to calculate the repetition maximum (1-RM) of internal rotation shoulder strength. A Pearson's correlation analysis with a 95% confidence interval (95% CI) was performed to determine whether correlations existed between dominant arm internal rotation strength characteristics and maximum and mean ball-throwing velocity. There is no correlation between the internal rotation strength of the throwing shoulder and the velocity of the ball in the standing handball throw.

Shoulder Internal Rotator Strength as Risk Factor for Shoulder Pain in Volleyball Players.

The aim of this study was to identify the intrinsic factors that could increase risk of shoulder pain in adolescent volleyball players. Twenty-eight young male volleyball players (between 14 and 18 years old) participated in this study. Athletes were submitted to: isokinetic muscle strength assessment of shoulder rotator muscles, ball service speed assessment, anterior and posterior drawer test, apprehension test, groove sign and scapular dyskinesia test. Athletes were followed for 16 weeks to monitor the presence of shoulder pain. All athletes were submitted to the same training protocol. During the 16 weeks, 28.5% of the athletes (n=8) experienced shoulder pain in the dominant limb higher than 3 according to Numerical Rating Scale criteria; 71.5% of the athletes (n=20) did not experience pain, or pain equal or lower than 3. The main result of our study was that the odds of feeling pain higher than 3 was significantly higher among players who presented higher values for internal rotation peak torque (OR=1.113, CI 95%=1.006 to 1.232 and p=0.038). The odds of feeling pain increased by 11% for every N·m of the internal rotator muscles. Pre-season isokinetic rotator strength assessments can help identify adolescent volleyball players at increased risk of a shoulder injury.

Prediction of Scapular Dyskinesis through Strength and Range of Motion of Shoulder Joint Rotation in Competitive Boxers

Background and Aims This study investigated the relationship between shoulder rotation Range of Motion (ROM), shoulder rotation strength, and sports history with scapular dyskinesia in competitive boxers. Methods The present study was a descriptive correlational study performed on 60 male boxers (age: 24/01±3/90 years; weight: 74/61±6/73 kg; height: 176/97±6/06 cm; and sports history: 5/16±1/84 years) in Guilan. Scapular dyskinesia by lateral scapular slide test, shoulder rotation ROM using a manual goniometer, and shoulder rotation strength using a manual dynamometer were measured. Data were analyzed by Pearson and Spearman correlations and multiple regression analysis. Results There were significant correlations between sports history (p= 0.001; r=0.589), shoulder internal rotation ROM (p=0.040; r=-0.255), shoulder external rotation ROM (p=0.001; r=0.486), shoulder internal rotation strength (p= 0.009; r=0.334), and shoulder external rotation strength (p=0.001; r=-0.620) and scapular dyskinesia. Regression analysis showed that 63.1% of scapular dyskinesia changes were related to the independent variables mentioned in this study. Conclusion It can be concluded that there is a significant relationship between shoulder rotation ROM, shoulder rotation strength, sports history, and scapular dyskinesia. Therefore, by strengthening and improving the scapular stabilizing muscles and consequently improving the shoulder rotation strength and shoulder rotation ROM in boxers, scapular dyskinesia or its intensification can be prevented.

Paper 11: Utility of Objective Testing for Initiation of a Throwing Program Following Shoulder and Elbow Surgery in Competitive Baseball Players

Paper 11: Utility of Objective Testing for Initiation of a Throwing Program Following Shoulder and Elbow Surgery in Competitive Baseball Players

Shoulder Strength and Upper Body Field Performance Tests in Young Female Handball and Volleyball Athletes: Are There Differences Between Sports?

Volleyball and handball players have usually been studied collectively as "overhead athletes," since throwing present similarities in the proximal to distal movement sequencing and upper limb joints ranges of motion. However, each sport presents specificities in the objectives when accelerating the ball and a variety of possible throwing techniques. Therefore, it is expected there may be differences in the shoulder and upper body physical performance between sports. The aim of this study was to determine if there are differences in shoulder muscle strength and upper body field performance tests between volleyball and handball athletes. Cross-sectional. Ninety-nine volleyball and handball female athletes aged between 13 and 20years were evaluated for isometric shoulder abductor and rotator strength (handheld dynamometer) and upper body field performance tests: Y Balance Test-Upper Quarter, modified Closed Kinetic Chain Upper-Extremity Stability Test, and unilateral and bilateral Seated Medicine Ball Throw. Handball athletes presented greater shoulder internal rotation strength (between-group difference: 2.84; effect size 0.70), higher medial (between-group difference: 9.54; effect size 0.90), superolateral (between-group differences: 8.9; effect size 0.68), and composite scores (between-group difference 5.7; effect size 0.75) of the Y Balance Test-Upper Quarter and higher unilateral (between-group difference: 41.92; effect size 0.91) and bilateral (between-group difference: 46.11; effect size 0.83) Seated Medicine Ball Throw performance. Groups were not different for Closed Kinetic Chain Upper-Extremity Stability Test, external rotation, and abduction isometric strength. Our findings suggest that young female handball athletes present greater internal rotator strength and better performance in Y Balance Test-Upper Quarter and Seated Medicine Ball Throw compared to volleyball players. These differences may be related to the different demands required in the throwing movements performed in each sport and should be considered when assessing these populations.

Differences in Shoulder Internal Rotation Strength Between Baseball Players With Ulnar Collateral Ligament Reconstruction and Healthy Controls.

Background:Studies have indicated decreased shoulder internal rotation (IR) and external rotation (ER) strength in the throwing limb of baseball players after ulnar collateral ligament injury. There is limited evidence on the recovery of shoulder rotation strength after primary ulnar collateral ligament reconstruction (UCLR).Hypothesis:At the time of return to throwing, baseball players who underwent UCLR would demonstrate decreased IR and ER shoulder strength in the throwing arm as compared with healthy baseball players.Study Design:Cross-sectional study; Level of evidence, 3.Methods:Male competitive high school and collegiate baseball athletes participated in this study. Athletes who underwent UCLR were compared with healthy controls who were matched by age, height, weight, and position. Bilateral isometric shoulder ER and IR strength was measured using a handheld dynamometer for all participants at the time of initial evaluation (UCLR group) and throughout the course of a season (healthy group). Independent t tests were run to calculate mean differences in ER and IR shoulder strength between the groups, with significance set at P < .05.Results:A total of 86 baseball athletes participated in this study (43 UCLR group, 43 healthy group). At the time of return to throwing (mean ± SD, 194 ± 30 days postoperatively), the 2 groups demonstrated no significant differences in nonthrowing arm ER or IR strength (P = .143 and .994, respectively). No significant difference was found between groups for throwing arm ER strength (P = .921); however, the UCLR group demonstrated significantly less throwing arm IR strength than the healthy group (144.2 ± 27.8 vs 157.6 ± 27.1 N; P = .023).Conclusion:The results of this study demonstrate that throwing arm rotator cuff strength may not fully recover before the initiation of a return-to-throwing program after UCLR. These data provide a potential framework for clinicians to assist in the management and exercise prescription of the baseball athlete after UCLR and before medical release and the initiation of a return-to-throwing program.

Isokinetic force-power profile of the shoulder joint in males participating in CrossFit training and competing at different levels.

BackgroundAs participants who engage in CrossFit training and competition perform a large volume of high intensity overhead activities, injuries to the shoulder are one of the most common in this sport. Previous research in other sports has indicated that the isokinetic force power profile of the shoulder joint (IPSJ) rotator muscles may assist in the prediction of shoulder injury.AimTherefore, the objective of this study was to determine the IPSJ in males engaged in CrossFit training at different competitive levels.MethodsIn a cross-sectional study design, participants (age, 24.1 ± 2.7 years) classified as ‘beginner’ (n = 6), ‘intermediate’ (n = 7) or ‘advanced’ (n = 9) provided informed consent to participate in this study. The IPSJ assessment involved rotational and diagonal movements, including internal and external shoulder rotator muscles, at both 180°.s−1 and 300°.s−1. The variables analysed were peak torque/body mass (%), mean power (W) and the external/internal peak torque/body mass ratio (%). A Kruskal–Wallis test was used to compare the IPSJ of the three groups, with Dunn’s test used for post-hoc analysis. The alpha level was set at p < 0.05.ResultsThe IPSJ showed greater torque and power values in those who competed at the advanced level as compared to those at a lower competitive level (i.e. intermediate, beginner). This was observed mainly for the internal rotation and internal diagonal movements at both 180°.s−1 and 300°.s−1. However, such differences between competitive levels were, in general, absent for the external rotation and external diagonal movements. Moreover, the participants from the advanced competitive level exhibited an imbalance of peak torque between the muscles responsible for the external–internal rotational and external-internal diagonal movements of the shoulder (i.e. peak torque external/internal ratio <66%), particularly in the dominant shoulder.ConclusionThese findings suggest greater development of the shoulder internal rotators and a higher probability of shoulder injury in CrossFit athletes at the advanced competitive level. Based on these results, participants engaged in CrossFit training and competition may wish to increase the volume of training for the shoulder external rotator muscles to complement the large increases in shoulder internal rotator strength that occur as a part of their regular training regimes.

The influence of testing positions and resistance locations on muscle activities during shoulder internal rotation strength measurements in young healthy adults

BackgroundAlthough some tests of shoulder internal rotator strength including subscapularis are commonly used in clinical practice, the differences in shoulder muscle activities other than subscapularis muscle among those tests are not well understood. The purpose of this study was to examine the activities of the superficial shoulder muscles in addition to internal rotation strength during two belly-press and three lift-off test positions. MethodsThirteen healthy young adult men (age 29.5 ± 5.4 years) were recruited for the present study. They performed isometric shoulder internal rotation against manual resistance during the belly-press test positions with two different resistance locations and the lift-off test with three different arm positions. The surface electromyographic activities of the superficial shoulder muscles, including the deltoid (anterior, middle, posterior), pectoralis major, long head of triceps and latissimus dorsi muscle, were collected and compared between the two belly-press tests, and among the three lift-off test positions (P < 0.05). ResultsThe belly-press test position with resistance to elbow showed significantly greater activities of the anterior and middle deltoid muscle than the original belly-press test; but showed significantly smaller activities of pectoralis major, triceps and latissimus dorsi muscle than the original belly-press test. Among the three lift-off tests, all muscle activities, except for the pectoralis major, were greater in the lift-off at L4/5 than in the lift-off at buttock and thigh. Lift-off at thigh showed significantly smaller activity of pectoralis major than the lift-off at L4/5 and buttock. ConclusionsThe findings of the present study suggest that clinician should give attention to compensatory motions by excessive shoulder extensor and adductor muscle activities for the original belly press test, by excessive deltoid muscle activities for the modified belly-press, and by excessive shoulder extensor muscle activities for the lift off test in the inferior arm positions.

Absolute Reliability and Concurrent Validity of Hand-Held Dynamometry in Shoulder Rotator Strength Assessment: Systematic Review and Meta-Analysis.

The purpose of this study is to establish the absolute reliability between hand-held dynamometers (HHDs) and concurrent validity between HHDs and isokinetic dynamometers (IDs) in shoulder rotator strength assessment. The Medline, CINAHL, and Central databases were searched for relevant studies up to July 2020. Absolute reliability was determined by test–retest studies presenting standard error of measurement (SEM%) and/or minimal detectable change (MDC%) expressed as percentage of the mean. Studies considering intra-class correlation coefficient (ICC) between IDs and HHDs were considered for concurrent validity. The risk of bias and the methodological quality were evaluated according to COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN). Thirteen studies were included in the meta-analysis. Shoulder internal rotator strength assessment MDC% was 0.78%, 95% confidence interval (CI) −5.21 to 3.66, while shoulder external rotators MDC% was 3.29%, CI −2.69 to 9.27. ICC between devices was 0.94, CI (0.91 to 0.96) for shoulder internal rotators and 0.92, IC (0.88 to 0.97) for shoulder external rotators. Very high correlation was found for shoulder rotator torque assessment between HHDs and IDs. The COSMIN checklist classified the selected studies as adequate and inadequate.

Identifying Risk Factors of Upper Extremity Injuries in Collegiate Baseball Players: A Pilot Study

BackgroundRepetitive pitching places tremendous forces on the shoulder and elbow which can lead to upper extremity (UE) or lower extremity (LE) overuse injuries.PurposeThe purpose of this study was to evaluate pre-season physical measurements in collegiate baseball players and track in-season baseball throwing volume to determine which factors may predict throwing overuse injuries.Study DesignRetrospective Cohort study.MethodsBaseline preseason mobility, strength, endurance, and perception of function were measured in 17 collegiate baseball pitchers. Participants were then followed during the course of the season to collect rate of individual exposure, estimated pitch volume, and rating of perceived exertion in order to determine if changes in workload contributed to risk of injury using an Acute-to-Chronic Workload ratio (ACWR).ResultsParticipants developing an injury had greater shoulder internal rotator strength (p=0.04) and grip strength in a neutral position (p=0.03). A significant relationship was identified between ACWR and UE injuries (p <0.001). Athletes with an ACWR above or below 33% were 8.3 (CI95 1.8-54.1) times more likely to suffer a throwing overuse injury occurring to the upper or lower extremity in the subsequent week.ConclusionACWR change in a positive or negative direction by 33% was the primary predictor of subsequent injury. This finding may assist sports medicine clinicians by using this threshold when tracking pitch volume to ensure a safe progression in workload during a baseball season to reduce the risk of sustaining overuse upper or lower extremity injuries.Level of Evidence3b

American Academy of Sports Physical Therapy Platform Presentation Abstracts SPL1–SPL82

American Academy of Sports Physical Therapy Platform Presentation Abstracts SPL1–SPL82

THE EFFECT OF HUMERAL RETROTORSION ON PITCH VELOCITY IN YOUTH BASEBALL PLAYERS

Pitching velocity is a critical measure of performance, but it may also play a role in the development of injury. It has been proposed that increased humeral retrotorsion (HRT) may be an advantageous adaptation among throwers, resulting in increased throwing velocity. However, there is limited published data directly investigating this relationship. The purpose of this study was to examine the effects of HRT on pitching velocity in a group of youth baseball players. We hypothesized that there would be a positive association between pitching velocity and increased humeral retrotorsion. Cross-sectional cohort study. Demographic and physical variables that may correlate to pitching velocity (age, height, weight, glenohumeral external rotation (ER) range of motion, dominant arm humeral retrotorsion and shoulder internal rotation (IR) strength) were assessed. Univariate analysis using Pearson correlation coefficients examined the relationship of each variable to pitching velocity. Significant variables were retained and entered into a multivariable regression analysis. All variables significantly correlated with pitching velocity (p<0.05) with the exception of ER (r = -0.169,p = 0.145). Multivariable regression model was significant and accounted for 81.7% of pitching velocity (R2 = 0.817 F(5,70) = 62.59,p<0.001). Player age (B = 1.7,p < 0.001), height (B = 0.225,p = 0.001) and shoulder IR strength (B = 0.622, p < 0.001) significantly contributed to the model. After accounting for all other variables, HRT had a non-significant (B = 0.005,p = 0.884) and very small contribution to pitching velocity adding only .005mph per degree of HRT. Pitching velocity in youth baseball players is strongly influenced by age, height and IR strength. In opposition to the hypothesis, the degree of humeral retrotorsion did not have a significant effect on pitching velocity. Level 3.

Is the Normal Shoulder Rotation Strength Ratio Altered in Elite Swimmers?

It is commonly believed that the shoulder external rotation (ER) to internal rotation (IR) strength ratio is decreased in swimmers due to predominant IR loading during the pull-through (propulsive) phase which predisposes to shoulder pain. However, the evidence supporting this hypothesis is inconclusive. Therefore, the aim of this study was to examine shoulder rotation strength parameters in elite swimmers and investigate potential associations with shoulder pain. Sixty-eight (40 men; age, 19.9 ± 3.2 yr) elite swimmers provided demographic and shoulder pain history data before measurement of shoulder rotation strength. Mixed model analyses were used to examine differences in shoulder IR and ER strength normalized to body weight (BW) and the shoulder rotation strength ratio. A multinomial logistic regression model was utilized to examine associations between shoulder rotation strength parameters and shoulder pain. Mean shoulder IR strength (BW) was approximately 0.29 for male swimmers and 0.26 for female swimmers. Mean shoulder ER strength (BW) was approximately 0.19 for male swimmers and 0.18 for female swimmer. The shoulder ER/IR strength ratio was approximately 0.70 bilaterally for all swimmers. There were no significant differences between dominant and nondominant shoulders in IR or ER strength normalized to BW (P ≥ 0.547). There were no associations between any shoulder strength parameters and shoulder pain (r = 0.032, P = 0.107). Despite the high IR loading, optimal swimming technique does not alter the normal ER/IR strength ratio at the shoulder. Elite swimmers who report current or a history of shoulder pain demonstrate normal shoulder rotation strength ratios. The finding of symmetrical shoulder rotation strength points to side-to-side strength comparisons as a valuable clinical tool in managing swimmers with unilateral shoulder pain.

Assessment of rotator cuff muscle strength and shoulder rotation range of motion in subjects with lateral epicondylitis

Background: Lateral epicondylitis (LE) is a common soft tissue condition treated by many physical therapists. It has poor long-term outcomes for the non-surgical management which suggests a less than optimal rehabilitation process, so there is a need to assess proximal kinetic chain. Objectives: The objective of the study is to compare shoulder rotator muscle strength and shoulder rotation range of motion (ROM) in patients with LE with age-matched healthy individuals. Materials and Methods: An observational study was conducted on 28 subjects with LE (Group A) and 28 age-matched healthy individuals (Group B), selected by convenience sampling. The strength of shoulder rotator muscles was assessed with the use of handheld dynamometer. Shoulder rotation ROM was assessed using standard goniometer. Results: Shoulder external rotators were 9% weaker on dominant side (P = 0.02) while no differences were seen for shoulder internal rotator (IR) strength (P = 0.2). For Group B, shoulder external rotators were 11% stronger on dominant side (P = 0.04), while No dominance difference was seen for shoulder IR strength (P = 0.5). For both Group A and Group B, shoulder rotation ROM showed no significant difference between dominant and non-dominant sides. For between-group analysis, shoulder rotation ROM and shoulder rotator strength showed no statistically significant difference between the Groups A and B. Conclusion: There is muscular imbalance of shoulder rotators in LE.