Effect of Scapular Stabilize Kinetic-chain Exercise on Scapular Dyskinesis  and Functional Internal Rotaion ROM in Collegiate Baseball Players

Abstract Context: Conditions such as labral and rotator cuff injuries have been linked with decreases in glenohumeral internal-rotation and increases in external-rotation motion. Also, decreased glenohumeral internal rotation is strongly associated with scapular dyskinesis. Objective: To compare healthy collegiate and high school baseball players' glenohumeral joint range of motion and scapular position. Design: Cross-sectional study. Setting: Institutional research laboratory. Patients or Other Participants: Thirty-one male National Collegiate Athletic Association Division I collegiate (age = 20.23 ± 1.17 years, height = 186.24 ± 5.73 cm, mass = 92.01 ± 7.68 kg) and 21 male high school baseball players (age = 16.57 ± 0.76 years, height = 180.58 ± 6.01 cm, mass = 79.09 ± 11.51 kg). Main Outcome Measure(s): Glenohumeral internal and external rotation and scapular upward rotation were measured with a digital inclinometer. Scapular protraction was measured with a vernier caliper. All variables except scapular upward rotation were calculated as the difference between the dominant and nondominant sides. Results: Collegiate baseball players had more glenohumeral internal-rotation deficit (4.80°, P = .028) and total motion deficit (5.73°, P = .009) and less glenohumeral external-rotation gain (3.00°, P = .028) than high school players. Collegiate baseball players had less scapular upward rotation than high school players at the 90° (4.12°, P = .015, versus 3.00°, P = .025) and 120° (4.00°, P = .007, versus 3.40°, P = .005) positions. The scapular protraction difference was greater in collegiate baseball players than in high school players in the hands-on-hips and 90° positions (0.77 cm, P = .021, and 1.4 cm, P = .001). Conclusions: When comparing high school with collegiate baseball players, these data suggest that glenohumeral internal-rotation deficit and scapular position change as the level of competition increases.

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Effects of Scapular Kinetic-Chain Exercise on Muscle Activity in Overhead-Pitching Baseball Players

Iranian Journal of Public Health ◽

10.18502/ijph.v49i5.3204 ◽

2020 ◽

Author(s):

Ki-Jae SONG ◽

Jin-Ho YOON ◽

Jae-Keun OH

Keyword(s):

Muscle Activity ◽

Muscle Activation ◽

Coracoid Process ◽

Scapular Dyskinesis ◽

Kinetic Chain ◽

Dominant Group ◽

Serratus Anterior ◽

Baseball Players ◽

Sports Science ◽

The Mean

Background: We aimed to demonstrate the effect of 8 wk of scapular kinetic-chain exercise on muscle activity in collegiate baseball players diagnosed with scapular dyskinesis. Methods: The subjects were career baseball players with at least a 7-year career assigned into either a SICK (S; scapular malposition, I; inferior border prominence, C; coracoid process pain, K; scapular dyskinesis; n=7) group or a normal group (n=16), respectively. The groups were further divided into SICK-Dominant, SICKNon-Dominant, Normal-Dominant, and Normal-Non-Dominant to examine the dominant and non-dominant deviation of each group. Twenty-three subjects finally recruited through the Sports Science Institute of Korea National Sport University, Seoul, Korea in Sep 2014. Subjects were only allowed drug treatment for acute injuries during matches or training, and matches, training, and diet were controlled by university dormitory life. Results: There was a significant increase in maximal muscular activation (MA) in elevation motion of NormalDominant upper trapezii (UT), mean MA of SICK-Dominant UT, and mean MA of SICK-Dominant lower trapezii (LT) (P<0.05). In depression motion, the mean MAs of SICK-Dominant, Normal-Dominant, and Normal-Non-Dominant UT were significantly increased (P<0.05). The maximal MA of Normal-Dominant LT was significantly increased (P=0.029), and the SICK-Dominant and Normal-Dominant groups showed significantly higher maximal and mean MAs after exercise compared with the Normal-Non-Dominant group (P<0.05). The maximal MA of SICK-Dominant musculi serratus anterior was significantly lower than NormalDominant at pre-test (P=0.034), and the mean MA of SICK-Dominant musculi serratus anterior differed from Normal-Dominant and Normal-Non-Dominant (P<0.05) before testing, but only from Normal-Non-Dominant after testing (P=0.031). Conclusion: Scapular kinetic-chain exercise improved muscle activation in both overhead-pitching players with scapular dyskinesis and normal players.

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Adaptation of muscle activity in scapular dyskinesis test for collegiate baseball players

Journal of Shoulder and Elbow Surgery ◽

10.1016/j.jse.2016.03.004 ◽

2016 ◽

Vol 25 (10) ◽

pp. 1583-1591 ◽

Cited By ~ 5

Author(s):

Masaaki Tsuruike ◽

Todd S. Ellenbecker

Keyword(s):

Muscle Activity ◽

Scapular Dyskinesis ◽

Baseball Players ◽

Collegiate Baseball

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Internal- and External-Rotation Peak Torque in Little League Baseball Players With Subacromial Impingement Syndrome: Improved by Closed Kinetic Chain Shoulder Training

Journal of Sport Rehabilitation ◽

10.1123/jsr.2014-0333 ◽

2016 ◽

Vol 25 (3) ◽

pp. 263-265 ◽

Cited By ~ 4

Author(s):

Dong-Rour Lee ◽

Laurentius Jongsoon Kim

Keyword(s):

Angular Velocity ◽

External Rotation ◽

Peak Torque ◽

Subacromial Impingement Syndrome ◽

Subacromial Impingement ◽

Kinetic Chain ◽

Baseball Players ◽

Little League ◽

Youth Baseball ◽

Closed Kinetic Chain

Context:Many studies have explored closed kinetic chain (CKC) shoulder exercises (SEs) with a sling because they are safer and more effective than open-chain exercises, especially in early stages of treatment. However, the application of CKC SE in youth baseball players has rarely been attempted, although teenage baseball players also experience shoulder pain.Objective:To investigate the effects of CKC SE on the peak torque of shoulder internal rotation (IR) and external rotation (ER) in youth baseball players.Design:Single-group pretest, posttest.Setting:Biomechanics laboratory.Participants:23 Little League Baseball players with subacromial impingement syndrome.Interventions:The CKC SE with a sling was CKC shoulder-flexion exercise, extension exercise, IR exercise, and ER exercise. This exercise regimen was conducted 2 or 3 times/wk for 8 wk.Main Outcome Measures:The peak torque of shoulder IR and ER was measured using an isokinetic dynamometer. Concentric shoulder rotation was performed, with 5 repetitions at an angular velocity of 60°/s and 15 at 180°/s.Results:The IR and ER peak torque significantly increased at each angular velocity after the exercise program. In particular, the increase in IR and ER peak torque values was statistically significant at an angular velocity of 180°/s.Conclusions:CKC SE was effective in increasing shoulder IR and ER strength, demonstrating its potential benefits in the prevention and treatment of shoulder injury. In addition, increased IR peak torque appears to improve throwing velocity in baseball players.

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