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Background: The Kerlan-Jobe Orthopaedic Clinic (KJOC) score has been used to describe various parameters of throwing shoulder and elbow function for the return to play after a long period of rehabilitation, such as after ulnar collateral ligament reconstruction. No study has yet to identify how scapular dyskinesis (SD) in baseball players affects the KJOC score. This study investigated the relationship of the KJOC score to SD evaluated in collegiate baseball players with and without upper extremity injury., Materials and Methods: The study participants were 30 male collegiate baseball players (13 pitchers) belonging to the National Collegiate Athletic Association D-I conference. Participants were assessed with the KJOC instrument in the beginning (PRE) and end (POST) of the season. The SD test was conducted (PRE) in shoulder flexion to identify SD RESULTS: The mean value of KJOC score was significantly less in POST than that of PRE for the pitchers with SD (89.3 and 60.5, respectively; P = .001), whereas no difference was found in the KJOC score between PRE and POST for the pitchers without SD. For the position players, no difference in the mean value of KJOC score was found between PRE and POST, regardless of SD., Conclusion: The results of this study provide evidence that collegiate baseball pitchers with mild SD may have lower KJOC scores, particularly setup or relief pitchers., (Copyright © 2018 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.)

Background: The characteristics of scapular muscle activities in elevation and descent exercises have yet to be elucidated to assess scapular dyskinesis. The purpose of this study was to identify the adaptation of electromyograph (EMG) activities of the upper trapezius (UT), lower trapezius (LT), serratus anterior (SA), and anterior deltoid (AD) muscles with different weight loads in flexion (FLX) and abduction (ABD) in collegiate baseball players., Materials and Methods: Twenty eight individuals, including 13 pitchers, were tested. Normalized EMG signals for the UT, LT, SA, AD muscle of the both the dominant (DOM) and nondominant (NON) side were blocked at every 1 second during each of the exercises. A 3-way repeated analysis of variance design was used to identify differences in the mean values between DOM and NON and between FLX and ABD for DOM., Results: The mean EMG value of the UT in the DOM was significantly less than that of the NON for all joint angles (P < .01), whereas the mean EMG value of the LT in the DOM was significantly greater than that of the NON (P < .01). In contrast, no difference in the SA EMG activity was determined between DOM and NON. However, the mean EMG value of SA in FLX was significantly greater than in ABD (P < .01)., Conclusion: This study identified an apparent adaptation of scapular muscle activities in the currently advocated scapular dyskinesis test for healthy active overhead athletes who are vulnerable to shoulder pathologies., (Copyright © 2016 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.)

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 [20°], 90/90 [90°]) 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.

Context: Proper scapular function during humeral elevation, such as upward rotation, external rotation, and posterior tilting of the scapula, is necessary to prevent shoulder injury. However, the appropriate intensity of rehabilitation exercise for the periscapular muscles has yet to be clarified., Objective: To identify the serratus anterior, lower trapezius, infraspinatus, and posterior deltoid muscle activities during 2 free-motion exercises using 3 intensities and to compare these muscle activities with isometric contractions during quadruped shoulder flexion and external rotation and abduction of the glenohumeral joint., Design: Cross-sectional study., Setting: Health Science Laboratory., Patients or Other Participants: A total of 16 uninjured, healthy, active, male college students (age = 19.5 ± 1.2 years, height = 173.1 ± 6.5 cm, weight = 68.8 ± 6.6 kg)., Main Outcome Measure(s): Mean electromyographic activity normalized by the maximal voluntary isometric contraction was analyzed across 3 intensities and 5 exercises. Intraclass correlation coefficients were calculated for electromyographic activity of the 4 muscles in each free-motion exercise., Results: Significant interactions in electromyographic activity were observed between intensities and exercises (P < .05). The quadruped shoulder-flexion exercise activated all 4 muscles compared with other exercises. Also, the modified robbery free-motion exercise activated the serratus anterior, lower trapezius, and infraspinatus compared with the lawn-mower free-motion exercise. However, neither exercise showed a difference in posterior deltoid electromyographic activity., Conclusions: Three intensities exposed the nature of the periscapular muscle activities across the different exercises. The free-motion exercise in periscapular muscle rehabilitation may not modify serratus anterior, lower trapezius, and infraspinatus muscle activities unless knee-joint extension is limited.

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.

Background A pattern of scapular dyskinesis on the dominant side has been demonstrated to be associated with a decrease in throwing arm conditions identified by a self-report outcome assessment in collegiate baseball pitchers during the course of a single season. However, it is unclear if symptomatic shoulders in baseball pitchers may be associated with the presence of scapular dyskinesis. Purpose To study the relationship between the presence of scapular dyskinesis and throwing-related injury in collegiate baseball pitchers during each respective course of up to four subsequent seasons. Methods A single Division 1 National Collegiate Athletic Association team participated in this study over a four-year-period. The scapular dyskinesis test was implemented during the preseason for baseball pitchers. Players were followed throughout each respective season to track the incidence of throwing-related upper extremity injuries. Results A total of 36 collegiate baseball pitchers (height: 185.3 ± 5.6 cm, weight: 88.8 ± 7.8 kg, age: 20.0 ± 1.5 years) consisting of 57 pitcher seasons were followed in this study, in which 18 pitchers remained with the team for more than one year. Twenty-seven of the 57 pitchers were classified as having scapular dyskinesis demonstrated at around 90° of shoulder flexion on the throwing side. Five injuries (13.2% of a total of 38 injuries) were diagnosed as throwing-related shoulder injuries during the course of the intercollegiate baseball seasons. Four of the five throwing-related shoulder injuries occurred in pitchers who had scapular dyskinesis on their dominant side. Consequently, the odds ratio was 5.04 for the collegiate pitchers with scapular dyskinesis on the throwing arm side associated with a throwing-related shoulder injury compared to those with no scapular dyskinesis (p = 0.16). No relationship was identified between scapular dyskinesis on the throwing arm side and throwing-related elbow injury. Eighty-one percent of the scapular dyskinesis test results were not changed on the throwing side from the previous to the following year for those 18 pitchers who were followed for more than one season, whereas 42.9% of the results remained unchanged on the non-throwing side. Conclusion The results suggest that collegiate baseball pitchers with dominant arm scapular dyskinesis likely are at increased risk of throwing-related shoulder injury. Level of evidence Level 2, Prospective Cohort Study [ABSTRACT FROM AUTHOR]

Background: Rehabilitation following shoulder surgery involves the use of resistive exercise but dosing of these exercises historically employs multiple sets of pre-determined repetitions and few reports document the perceived effort encountered by patients during these exercises for both elastic resistance and free-weights. The OMNI-Resistance Exercise Scale (OMNI-RES) has been tested and applied as a measure of perceived exertion (RPE) for resistive exercise but has not gained widespread acceptance as an optimal method for physical therapists to document RPE during rehabilitation of shoulder surgery. Purpose: To generate descriptive values of RPE encountered during common shoulder exercises of varying resistance in patients following shoulder surgery as well as provide a comparative analysis between perceived exertion ratings of similar exercise movement patterns using elastic and traditional isotonic resistance. Study Design: Descriptive Cross-sectional Cohort Methods: Sixty-six subjects (mean age 53.3+12.8 years) were included in this study following shoulder surgery (RC repair n=22, labral repair n=10, SA n=34). Perceived exertion using the OMNI-RES was recorded during performance of seven rotator cuff and scapular rehabilitation exercises at 6- and 12-weeks following surgery. Results: Mean RPE using OMNI-RES in combined surgical groups ranged between 3.6 and 5.7 (mean = 4.50+2.1) across all seven exercises (scale 0 = very easy to 10 = extremely hard). From the external rotation (ER) exercise pair, paired t-tests revealed standing ER w/ Thera-band® (ERB) had a significantly higher OMNI-RES score versus sidelying ER w/ cuff weight (SLERW) (mean: 5.13 vs 4.41, p = 0.001) while the extension exercise pair consisting of standing shoulder extension w/ band (EXTB) and prone extension w/ cuff weight (PEXTW) showed no significant difference in OMNI-RES score (mean: 3.54, 3.67, p = 0.626). Conclusion: Commonly prescribed resistance exercise in the rehabilitation following shoulder surgery show lightmoderate ratings of perceived exertion at both 6 & 12 week post-operative timepoints across three surgical procedures. [ABSTRACT FROM AUTHOR]

Background: Little is known about the optimal exercise intensity and the effects of arm position on elastic resistance exercise. The purpose of this study was to investigate scapular muscle activity in different arm positions utilized during standing elastic resistance exercise.Hypothesis: Lower trapezius (LT), serratus anterior (SA), and infraspinatus (IS) muscle activity will vary across arm positions above shoulder level. Also, oscillation resistance exercise will result in increased muscle activity compared with isometric contraction.Study Design: Controlled laboratory study.Level Of Evidence: Level 4.Methods: A total of 19 uninjured male collegiate baseball players volunteered to participate in this study. The electromyography (EMG) activity of the LT, upper trapezius (UT), middle deltoid (MD), SA, and IS muscles was determined using surface EMG in 3 arm positions: diagonal pattern 1 (D1), 120° of shoulder abduction (120), and 90° shoulder abduction with external rotation and elbow flexion (90/90) during both isometric contraction and oscillation resistance exercise.Results: No difference in EMG activity of the LT muscle was found between the 120 and 90/90 position. However, the 120 position increased UT and MD muscle activity significantly more than those of the 90/90 position. The D1 arm position significantly increased SA muscle activity more than the 120 and 90/90 positions while the LT muscle activity was nearly silent.Conclusion: The standing 90/90 position effectively generated both LT and IS muscle EMG activity while minimizing both UT and MD muscle activity.Clinical Relevance: The use of oscillation movements under elastic loading can create high muscle activation in the LT muscle without an adverse effect of the humeral head position and scapular rotation. [ABSTRACT FROM AUTHOR]

The article discusses a case report that describes the use of the scapular dyskinesis (SD) test to assess the scapular muscles and reports electromyography (EMG) findings in a college baseball pitcher diagnosed with a Type 2 posterior superior labrum anterior-posterior lesion. Highlights include the presences of Type I and II SD that alter the safe zone of glenohumeral angle, mean EMG value of the upper trapezius (UT) on the dominant side, and ratio of UT to lower trapezius muscle EMG activity.

Background: Hyperactivity of the anterior deltoid (AD) has been shown to produce adverse effects on subacromial space width as a result of humeral head superior translation during rehabilitation exercises used with overhead athletes. Also, the importance of the ratio of upper trapezius (UT) to lower trapezius (LT) muscle activity has been examined during rehabilitation exercises particularly for those who develop scapular dyskinesis. Hypothesis/Purpose: The purpose of this study was to investigate the level of LT and SA muscle activity during scapular plane elevation (scaption) in three po sitions while maintaining a moderate level of AD muscle activity. A secondary purpose was to identify the ratio of UT to LT muscle activity during the varied scaption exercises. The authors hypothesized that the activation of these two important muscles and the UT/LT ratio would vary with exercise position an d throughout the range of scapular plane elevation. Methods: Fourteen active young subjects performed scaption exercises in three different positions: standing (STAN), quadruped (QUAD), and prone (PRON) with three different weight loads: 0 kg, 1.8 kg, and 4.1 kg. Surface electromyography (EMG) was used to record muscular activity. Tested muscles included the UT, LT, SA, AD, and posterior deltoid muscles on the dominant side. Results: QUAD scaption exercises with a load of 1.8 kg at 4 sec after the initial movement activated the LT muscle up to 49% of maximum voluntary isometric contraction (MVIC) while maintaining a moderate level of AD muscle activity (30% MVIC). STAN scaption exercises with the weight load of 1.8 kg at 3 sec after the initial movement activated 43% MVIC of the SA muscle while maintaining a moderate level of AD muscle activity (39% MVIC). Th e PRON condition generated significantly less SA muscle activity with both 1.8 and 4.1 kg weight loads than during the QUAD condition. The ratios of UT to LT muscle activity were significantly less in QUAD than those of STAN up to 4 sec after the initial movement. No significant difference was observed in the UT/LT ratio between QUAD and PRON conditions. Conclusion: QUAD scaption exercise effectively activated both LT and SA muscles wi thout over activating the AD and produced favorable ratios of UT to LT muscle activity. Level of Evidence: Descriptive Cohort Study, Level 4 [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]