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The article discusses the study by the author to identify the serratus anterior, lower trapezius, infraspinatus, and posterior deltoid muscle activities during two free-motion exercises. It mentions comparison of the muscle activities with isometric contractions during quadruped shoulder flexion and external rotation and abduction of the glenohumeral joint. It reports that interactions in electromyographic activity were observed between intensities and exercises.

Rehabilitation of the patient with glenohumeral impingement requires a complete understanding of the structures involved and the underlying mechanism creating the impingement response. A detailed clinical examination and comprehensive treatment programme including specifi c interventions to address pain, scapular dysfunction and rotator cuff weakness are recommended. The inclusion of objective testing to quantify range of motion and both muscular strength and balance in addition to the manual orthopaedic clinical tests allows clinicians to design evidencebased rehabilitation programmes as well as measure progression and patient improvement. [ABSTRACT FROM AUTHOR]

Background: Tennis requires repetitive multidirectional movement patterns that can lead to lower extremity injury. Knowledge of population and age-specific strength parameters can be used during performance enhancement training and rehabilitation of tennis players. Objectives: The purpose of this study was to generate population and age-specific descriptive profiles of concentric isokinetic knee extension and flexion strength in elite junior tennis players, and determine whether bilateral differences exist between extremities and across age ranges. Methods: A total of 103 elite male tennis players (mean (SD) 15.92 (2.14), range 11–21) and 53 female tennis players (mean (SD) 15.0 (2.30, range 11–21) were isokinetically tested on a Cybex 6000 isokinetic dynamometer at 180 and 300∗/s to assess bilateral concentric knee extension and flexion strength using a standard bilateral testing protocol. Results: No significant bilateral difference between the dominant (racquet side) lower extremity and the contralateral non-dominant side were measured in lower extremity knee extension or flexion strength normalised to body weight, or in the hamstring quadriceps strength ratios in male and female subjects. Male subjects did show significant (p<0.001) increases in knee extension and flexion strength across the age ranges from 11–15 years of age to 16–21 years. Female subjects did not show any significant change in the normalised knee extension or flexion strength across age ranges. Hamstring/quadriceps strength ratios were bilaterally symmetric and remained clinically and statistically constant across age ranges for the male and female elite tennis players. Conclusions: Population and age-specific isokinetic descriptive data from elite tennis players can provide guidance in the development and monitoring of performance enhancement and rehabilitation programs for elite tennis players. The changes identified in normalised knee extension and flexion strength in elite male tennis players necessitate the use of population and age-specific descriptive data. [ABSTRACT FROM AUTHOR]

Background: Repetitive loading to the hip joint in athletes has been reported as a factor in the development of degenerative joint disease and intra-articular injury. Little information is available on the bilateral symmetry of hip rotational measures in unilaterally dominant upper extremity athletes. Hypothesis: Side-to-side differences in hip joint range of motion may be present because of asymmetrical loading in the lower extremities of elite tennis players and professional baseball pitchers. Study Design: Cohort (cross-sectional) study (prevalence); Level of evidence, 1. Methods: Descriptive measures of hip internal and external rotation active range of motion were taken in the prone position of 64 male and 83 female elite tennis players and 101 male professional baseball pitchers using digital photos and computerized angle calculation software. Bilateral differences in active range of motion between the dominant and nondominant hip were compared using paired t tests and Bonferroni correction for hip internal, external, and total rotation range of motion. A Pearson correlation test was used to test the relationship between years of competition and hip rotation active range of motion. Results: No significant bilateral difference (P > .005) was measured for mean hip internal or external rotation for the elite tennis players or the professional baseball pitchers. An analysis of the number of subjects in each group with a bilateral difference in hip rotation greater than 10° identified 17% of the professional baseball pitchers with internal rotation differences and 42% with external rotation differences. Differences in the elite male tennis players occurred in only 15% of the players for internal rotation and 9% in external rotation. Female subjects had differences in 8% and 12% of the players for internal and external rotation, respectively. Statistical differences were found between the mean total arc of hip range of internal and external rotation in the elite tennis players with the dominant side being greater by a clinically insignificant mean value of 2.5°. Significantly less (P < .005) dominant hip internal rotation and less dominant and nondominant hip total rotation range of motion were found in the professional baseball pitchers compared with the elite male tennis players. Conclusion: This study established typical range of motion patterns and identified bilaterally symmetric hip active range of motion rotation values in elite tennis players and professional baseball pitchers. Asymmetric hip joint rotational active range of motion encountered during clinical examination and screening may indicate abnormalities and would indicate the application of flexibility training, rehabilitation, and further evaluation. [ABSTRACT FROM AUTHOR]

Presents a study which compared the manual laxity testing with stress radiography for quantifying humeral head translation in the throwing athlete's shoulder. Role of the anterior portion of the inferior glenohumeral ligament; How the study was conducted; Results and discussion.

Presents information on a study regarding the differences in medial elbow laxity that exist between the dominant and nondominant extremities of professional baseball pitchers. Materials and methodology of the study; Results of the study; Discussion of the results.

The author discusses the intervention strategies for optimizing player performance regardless of environmental or temperature conditions employed by the Association of Tennis Professionals (ATP) and the Women's Tennis Association (WTA). He explains the impact of environmental heat on players' core body temperatures (CBT) and how the temperature can affect their health and performance. He states that knowledge of sweat rates and physiological cooling can help players perform better.

The term physical literacy has been embraced by a number of different countries around the world. Although the concept has regained momentum over the past few decades, little has been written about specific activities that may assist in providing the foundation for physical literacy as a life-long journey. This article introduces selected physical training concepts and activities based on national standards. Key benefits and teaching objectives related to both performance enhancement and injury prevention are provided. [ABSTRACT FROM AUTHOR]

Context: The appropriate resistance intensity to prescribe for shoulder rehabilitative exercise is not completely known. Excessive activation of the deltoid and upper trapezius muscles could be counterproductive for scapulohumeral rhythm during humeral elevation. Objective: To identify the effects of different exercise intensities on the scapular muscles during a free-motion "robbery" exercise performed in different degrees of shoulder abduction in seated and standing positions. Design: Descriptive laboratory study. Setting: Kinesiology Adapted Physical Education Laboratory. Patients or Other Participants: A total of 15 healthy male college students (age = 20.5 ± 2.2 years, height = 174.5 ± 5.3 cm, mass = 63.8 ± 6.0 kg). Intervention(s): Participants performed 5 repetitions of a randomized exercise sequence of the robbery exercise in 2 body positions (seated, standing), 2 shoulder-abducted positions (W [208], 90/90 [908]) at 3 intensities (0%, 3%, and 7% body weight). Main Outcome Measure(s): Electromyographic (EMG) activity of the upper trapezius, lower trapezius, serratus anterior, anterior deltoid, and infraspinatus muscles of the upper extremity was collected. All EMG activities were normalized by the maximal voluntary isometric contraction of each corresponding muscle (%). Results: The serratus anterior, anterior deltoid, and infraspinatus EMG activities were greater at 7% body weight in the seated position compared with the standing position (P <.05). The EMG activities in all 5 muscles were greater in the 90/90 position than in the W position (P <.05). Conclusions: Scapular muscle activity modulated relative to changes in body posture and resistance intensity. These findings will enable clinicians to prescribe the appropriate level of exercise intensity and positioning during shoulder rehabilitation. [ABSTRACT FROM AUTHOR]

Background This article describes the best clinical tests of shoulder function and injury as identifi ed in a recent systematic review published in the British Journal of Sports Medicine. Discussion A description of the different tests is given, with photographs of the exact test procedure. [ABSTRACT FROM AUTHOR]

Background: Cementless humeral resurfacing arthroplasty is a bone-conserving arthroplasty option for patients with glenohumeral arthritis. It has been successful in the older patient population. However, data regarding the results of arthroplasty in younger, more active patients are lacking. We report the two-year results of this procedure in active patients who were less than fifty-five years of age. Methods: We reviewed prospectively collected clinical data on a series of thirty-six patients under fifty-five years of age with end-stage glenohumeral arthrosis, but without osteonecrosis, who had undergone a cementless humeral resurfacing hemiarthroplasty performed by a single surgeon. All patients were followed for a minimum of two years. We assessed pain, function, and patient satisfaction and documented all complications. Radiographs were evaluated for implant loosening. Results: The thirty-six patients had a mean age of 42.3 years and were followed for a mean of 38.1 months. Scores measured with a visual analog pain scale, the Single Assessment Numeric Evaluation (SANE) scale, and the American Shoulder and Elbow Surgeons (ASES) scale all improved significantly from preoperatively to two years postoperatively (p < 0.001). Complications included one traumatic subscapularis rupture at six weeks, three cases of arthrofibrosis, and one deep hematoma. No obvious radiographic evidence of loosening was noted at the time of the latest follow-up. One shoulder was converted to a stemmed total shoulder arthroplasty at twenty-four months because of pain, but the implant was not loose at the revision. The remaining thirty-five patients were satisfied with the outcome at the time of the latest follow-up and had returned to their desired activity. Conclusions: Cementless humeral resurfacing arthroplasty is a viable treatment option for younger, active patients. Early results indicate that the desired function and pain relief can be expected. [ABSTRACT FROM AUTHOR]

Background: Throwing injuries of the shoulder and elbow are common among youth baseball players. Hypothesis: A prevention program will reduce the incidence of throwing injuries of the shoulder and elbow by 50% among youth baseball players. Study Design: Randomized controlled trial; Level of evidence, 1. Methods: The authors block randomized 16 youth baseball teams consisting of 237 players aged 9 to 11 years into an intervention group (8 teams, 117 players) and a control group (8 teams, 120 players). The intervention program consisted of 5 stretching, 2 dynamic mobility, and 2 balance training exercises performed during warm-up. Both groups were followed up for 12 months, during which the incidence of shoulder and elbow injuries was recorded. In addition, ball speed during pitching as a performance-related factor and variables of physical function (passive range of motion of the elbow, shoulder and hip, dynamic balance, and thoracic kyphosis angle) were assessed during the pre- and postintervention periods. Results: The incidence of shoulder and elbow injuries in the intervention group (1.7 per 1000 athlete-exposures) was significantly lower than that in the control group (3.1 per 1000 athlete-exposures) (hazard ratio, 1.940; 95% CI, 1.175-3.205; P =.010). The factors related to pitching performance, as assessed by ball speed, tended to increase in the intervention group as compared with the control group (P =.010). The program also improved shoulder horizontal adduction deficits on the dominant side, hip internal rotation on the nondominant side, and the thoracic kyphosis angle. Conclusion: A prevention program decreases throwing injuries of the shoulder and elbow and enhances the parameter of pitching performance in youth baseball players. [ABSTRACT FROM AUTHOR]

Background: Clinically evaluating the scapulothoracic joint is challenging. To identify scapular dyskinesis, clinicians typically observe scapular motion and congruence during self-directed upper extremity movements. However, it is unclear whether this method is reliable.Questions/purposes: We therefore determined the interrater reliability of a scapular classification system in the examination of professional baseball players.Methods: Seventy-one healthy uninjured professional baseball players between the ages of 18 and 32 years volunteered to participate. We used a digital video camera to film five repetitions of scapular plane elevation while holding a 2-pound weight. Four examiners then independently classified the motions on video into one of four types. Interrater reliability analysis using the kappa (k) statistic was performed for: (1) classifying each scapula into one of the four types; (2) classifying each scapula as being abnormal (Types I-III) or normal (Type IV); and (3) classifying both scapula as both being symmetric (both normal or both abnormal) or asymmetric (one normal, one abnormal).Results: We found low reliability for all analyses. In classifying each scapula as one of the four types, reliability was k = 0.245 for the left limb and k = 0.186 for the right limb. When considering the dichotomous classifications (abnormal versus normal), reliability was k = 0.264 for left and k = 0.157 for right. For bilateral symmetry/asymmetric, reliability was k = 0.084.Conclusion: We found low reliability of visual observation and classification of scapular movement.Clinical Relevance: Current evaluation strategies for evaluating subtle scapular abnormalities are limited.Level Of Evidence: Level III, diagnostic study. See Guidelines for Authors for a complete description of levels of evidence. [ABSTRACT FROM AUTHOR]

Context: Participation in high school sports has grown 16.1% over the last decade, but few studies have compared the overall injury risks in girls' softball and boys' baseball. Objective: To examine the incidence of injury in high school softball and baseball players. Design: Cohort study. Setting: Greenville, South Carolina, high schools. Patients or Other Participants: Softball and baseball players (n = 247) from 11 high schools. Main Outcome Measure(s): Injury rates, locations, types; initial or subsequent injury; practice or game setting; positions played; seasonal trends. Results: The overall incidence injury rate was 4.5/1000 athlete-exposures (AEs), with more injuries overall in softball players (5.6/1000 AEs) than in baseball players (4.0/1000 AEs). Baseball players had a higher initial injury rate (75.9/1000 AEs) than softball players (66.4/1000 AEs): rate ratio (RR) = 0.88, 95% confidence interval (CI) = 0.4,1.7. The initial injury rate was higher than the subsequent injury rate for the overall sample (P<.0001) and for softball (P<.0001) and baseball (P<.001) players. For both sports, the injury rate during games (4.6/1000 AEs) was similar to that during practices (4.1/1000 AEs), RR = 1.22, 95% CI = 0.7, 2.2. Softball players were more likely to be injured in a game than were baseball players (RR = 1.92, 95% CI = 0.8, 4.3). Most injuries (77%) were mild (3.5/1000 AEs). The upper extremity accounted for the highest proportion of injuries (63.3%). The incidence of injury for pitchers was 37.3% and for position players was 15.3%. The rate of injury was highest during the first month of the season (7.96/1000 AEs). Conclusions: The incidence of injury was low for both soft- ball and baseball. Most injuries were minor and affected the upper extremity. The injury rates were highest in the first month of the season, so prevention strategies should be focused on minimizing injuries and monitoring players early in the season. [ABSTRACT FROM AUTHOR]

Background: Range of motion deficits in shoulder external rotation (ER), internal rotation (IR), total rotation range of motion (ER + IR), and horizontal adduction (HA) have been retrospectively associated with overhand athletes’ arm injuries.Hypothesis: The authors expected the incidence of upper extremity injury in high school softball and baseball players with side-to-side shoulder range of motion deficits to be greater than the incidence of upper extremity injury in players with normal shoulder range of motion.Study Design: Cohort study (prognosis); Level of evidence, 2.Methods: High school softball and baseball players (N = 246) participated. Before the start of the season, passive shoulder ER, IR, and HA were assessed at 90° of abduction with the scapula stabilized. Relative risk (RR) was calculated to examine range of motion measure, by categorical criteria, and risk of upper extremity injury.Results: Twenty-seven shoulder and elbow injuries (9 softball, 18 baseball) were observed during the season. The dominant shoulder of all injured players and baseball players displayed a significant decrease in HA (P = .05) and IR (P = .04). The dominant shoulder total rotation of injured baseball players displayed a significant decrease (mean difference = 8.0° ± 0.1°; P = .05) as compared with the dominant shoulder of uninjured baseball players. Players who displayed a decrease of ≥25° of IR in the dominant shoulder were at 4 times greater risk of upper extremity injury compared with players with a <25° decrease in IR, especially for baseball players. While we observed a 1.5 to 2 times increased risk of injury for the 10° to 20° loss in rotational range of motion for the overall sample and baseball, the risk estimates were not statistically significant (P > .05).Conclusion: There are large mean deficits in shoulder IR and HA between injured and noninjured players, but not in ER or total rotation. Passive shoulder IR loss ≥25° as compared bilaterally was predictive of arm injury. Shoulder range of motion deficits differed between sports and appeared more predictive of injury for baseball players. [ABSTRACT FROM AUTHOR]

The purpose of this descriptive study was to determine whether bilateral differences exist in concentric and eccentric shoulder internal and external rotation strength in high school aged baseball pitchers. Thirty-nine high school aged baseball pitchers were bilaterally tested for concentric and eccentric internal and external rotation muscle performance on a Kin-Com 500-H isokinetic dynamometer at 908·s-1 and 1808·s-1. Paired t-tests were used to test for differences among extremities, speed, and ratio of external rotation to internal rotation (ER/IR ratios). Concentric peak torque internal rotation at 908·s-1 was significantly greater (p < 0.05) in the dominant arm compared with the nondominant arm. Statistically significant differences (p < 0.001) were found between the nondominant and dominant in concentric 908·s-1. The nondominant arm demonstrated significantly greater eccentric strength (p < 0.05) compared with the dominant arm in ER/IR ratios at 908·s-1 and 1808·s-1. The nondominant arm demonstrated significantly greater eccentric strength (p < 0.05) than the dominant arm in ER/IR ratio at 1808·s-1. Data demonstrated that muscular adaptations are consistent with previous research in this area. Also, muscular adaptations occur in the shoulder in the high school aged population. These data can serve as a guideline to be used by clinicians who rehabilitate shoulders in patients in this population. [ABSTRACT FROM AUTHOR]

Rotator cuff function is critical to the overhead athlete. Rotator cuff power is felt to be important in the overhead athlete during the throwing motion. Little research exists regarding torque acceleration energy (TAE) in overhead athletes. Twenty-five males were divided into 2 groups consisting of overhead athletes (pitchers) (n = 12) and nonoverhead athletes (controls) (n = 13). All participants were given a concentric velocity spectrum isokinetic test at speeds of 608 (1.05 r), 1808 (3.16 r), and 3008·s-1 (5.26 r) to both the dominant and nondominant shoulder internal and external rotators. Significant differences were found for all internal rotator TAE scores (p = 0.000-0.016), at each of the 3 velocities, when comparing dominant to nondominant arms of both overhead athletes and nonoverhead athletes. Only 608·s-1(1.05 r) was found to be different during external rotation TAE testing of the overhead athletes (p = 0.027) but was not found in the control subjects. Post hoc analysis revealed no differences between dominant or nondominant TAE scores when comparisons were made between overhead athletes and controls. Results may reveal that power of the rotator cuff muscles may not be a critical component of the overhead throwing motion. [ABSTRACT FROM AUTHOR]

A letter to the editor is presented in response to the article "Shoulder Range of Motion Measures as Risk Factors for Shoulder and Elbow Injuries in High School Softball and Baseball Players," by Shanley and colleagues in the June 17, 2011 issue.