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

2016 ◽  
Vol 25 (3) ◽  
pp. 263-265 ◽  
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.

scholarly journals A Preliminary Examination of Shoulder Joint Function Following Shoulder Complex Training and In-Season Play in Youth Baseball Players

2020 ◽  
Vol 8 (4) ◽  
pp. 59
Author(s):  
Kevin M. Carlson ◽  
Kayla Tweedt ◽  
Miranda Strelecki ◽  
Ian Malaby ◽  
Collin Seymour
Keyword(s):  
Shoulder Joint ◽  
External Rotation ◽  
Average Power ◽  
Peak Torque ◽  
Joint Rotation ◽  
Baseball Players ◽  
Youth Baseball ◽  
Post Test ◽  
Shoulder Complex ◽  
Complex Training

Background: As shoulder care continues to be a concern for youth baseball players, coaches, parents, researchers and clinicians, shoulder complex care should remain a point of emphasis especially for in overhead athletes. The impact of throwing volume and shoulder care is important for us to understand. Objective: The purpose was to examine the changes in shoulder complex function during a playing season combined with shoulder complex training in young male baseball players. Methods: Eleven male baseball players (11-15 y/o) served as subjects. Pre-testing included shoulder joint internal/external rotation peak torque and average work as measured with isokinetic dynamometry (Biodex System 4Pro). Training over the 18-week project duration was Crossover Symmetry “Activation” and “Strength” protocols completed per manufacturer recommendations. Adherence was tracked via a weekly email sent to the subject’s guardian to self-report completed training. Post-testing was conducted at the conclusion of the 18th week. Paired sample t-tests compared pre-test and post-test mean differences for peak torque and average power (p<0.05). Results: All-subject average for training was 54 sessions over the 18 weeks. Estimated number of throws completed during practice and games over the 18 weeks was 8,400. For both testing speeds and for both internal and external shoulder joint rotation, peak torque increases ranged from ~50% for external rotation at 60 deg/s up to ~200% for internal rotation at 120 deg/s. Statistical differences (p<0.001) were noted between all pre-test and post-test internal and external rotation peak torque values. For both testing speeds and for both internal and external shoulder joint rotation, average power increases ranged from ~38% at 60 deg/s for external rotation up to ~200% at 120 deg/s for internal rotation. Statistical differences (p<0.005) were noted between all pre-test and post-test internal and external rotation average power values. Conclusions: Substantial increases in shoulder joint rotation peak torques and power were seen across the 18-week study duration. As this was a preliminary investigation, we have yet to discern if these increases are due to the shoulder complex training or volume of throwing that was completed.

Hip internal and external rotation range of motion reliability in youth baseball players

2020 ◽  
Vol 61 (1) ◽  
Author(s):  
Garrett S. Bullock ◽  
Edward C. Beck ◽  
Gary S. Collins ◽  
Stephanie R. Filbay ◽  
Kristen F. Nicholson
Keyword(s):  
Range Of Motion ◽  
External Rotation ◽  
Baseball Players ◽  
Youth Baseball

The Impact of Tennis and Golfer’s Elbow on Shoulder External Rotators and Abductors’ Peak Torque

2020 ◽  
Vol 29 (4) ◽  
pp. 469-475
Author(s):  
Bassam A. Nabil ◽  
Mariam A. Ameer ◽  
Azza M. Abdelmohsen ◽  
Abeer F. Hanafy ◽  
Ahmed S. Yamani ◽  
...  
Keyword(s):  
Angular Velocity ◽  
Upper Limb ◽  
Tennis Elbow ◽  
Peak Torque ◽  
Healthy Control Group ◽  
Control Group ◽  
Kinetic Chain ◽  
Healthy Control ◽  
External Rotator ◽  
Golfer’S Elbow

Context: Upper limb activities require a repetitive movement of the shoulder external rotator and abductor muscles. The malfunction of the proximal part of the upper limb kinetic chain tends to change the mechanics of the distal part and increase the risk of injuries. Objectives: To compare the normalized eccentric peak torque (NEPT) of the shoulder external rotator and abductor muscles among healthy athletes and those with tennis elbow and golfer’s elbow. Design: An experimental cross-sectional study. Setting: Isokinetic laboratory, Faculty of Physical Therapy, Cairo University. Participants: A total of 30 male athletes participated voluntarily in this study. Intervention: Participants were distributed into 3 groups: healthy group, tennis elbow group, and golfer’s elbow group. Main Outcome Measures: NEPT of shoulder abductors and external rotators. The Biodex Isokinetic Dynamometer was used to measure the variables of interest. Results: There was a significant increase in the NEPT of shoulder abductors and external rotators in healthy control group compared with both tennis elbow and golfer’s elbow groups at an angular velocity of 60°/s (P < .05). Moreover, there was a significant increase in the NEPT of shoulder external rotators and abductors at an angular velocity of 120°/s in healthy control group compared with tennis elbow group and in golfer’s elbow group compared with tennis elbow group (P < .05). Conclusion: Tennis elbow and golfer’s elbow are associated with decreased NEPT of shoulder external rotators and abductors compared with those of healthy athletes. This tends to decrease the external stability of the shoulder joint and put high stress on the distal joints of the upper kinetic chain.

Biomechanics of the Shoulder in Youth Baseball Pitchers

2005 ◽  
Vol 33 (11) ◽  
pp. 1716-1722 ◽  
Author(s):  
Michelle B. Sabick ◽  
Young-Kyu Kim ◽  
Michael R. Torry ◽  
Michael A. Keirns ◽  
Richard J. Hawkins
Keyword(s):  
Body Weight ◽  
External Rotation ◽  
Pitching Motion ◽  
Little League ◽  
Youth Baseball ◽  
Shoulder External Rotation ◽  
Baseball Pitchers ◽  
Force Components ◽  
Simulated Game ◽  
Distraction Force

Background The effects of repetitive throwing on the shoulders of developing athletes are not well understood because of the paucity of data describing the biomechanics of youth pitchers and the plasticity of the developing skeleton. Hypothesis The direction and magnitude of the stresses that exist at the proximal humeral physis during the fastball pitching motion are consistent with the development of proximal humeral epiphysiolysis (Little League shoulder) and/or humeral retrotorsion. Study Design Descriptive laboratory study. Methods A total of 14 elite youth baseball pitchers (mean age, 12.1 ± 0.4 years) were filmed from the front and dominant side while throwing fastballs in a simulated game. The net force and torque acting on the humerus throughout the throwing motion were calculated using standard biomechanical techniques. Results The external rotation torque about the long axis of the humerus reached a peak value of 17.7 ± 3.5 N.m (2.7% ± 0.3% body weight × height) just before maximum shoulder external rotation. A shoulder distraction force of 214.7 ± 47.2 N (49.8% ± 8.3% body weight) occurred at, or just after, ball release. Conclusion Shear stress arising from the high torque late in the arm-cocking phase is large enough to lead to deformation of the weak proximal humeral epiphyseal cartilage, causing either humeral retrotorsion or proximal humeral epiphysiolysis over time. The stresses generated by the external rotation torque are much greater than those caused by distraction forces generated during the pitching motion of youth baseball pitchers. Clinical Relevance The motion of throwing fastballs by youth baseball pitchers results in force components consistent with proposed mechanisms for 2 clinical entities.

scholarly journals Are the Current Little League Pitching Guidelines Adequate? A Single-Season Prospective MRI Study

2017 ◽  
Vol 5 (5) ◽  
pp. 232596711770485 ◽  
Author(s):  
Andrew V. Pytiak ◽  
Phillip Stearns ◽  
Tracey P. Bastrom ◽  
Jerry Dwek ◽  
Peter Kruk ◽  
...  
Keyword(s):  
Physical Examination ◽  
Significant Loss ◽  
Mri Findings ◽  
Level Of Evidence ◽  
Baseball Players ◽  
Guideline Compliance ◽  
Arm Pain ◽  
Little League ◽  
Significant Difference ◽  
Youth Baseball

Background: Little League throwing guidelines have recently been implemented in an attempt to lessen the growing number of elbow injuries occurring in youth baseball players. Hypothesis/Purpose: The purpose of this study was to examine pre- and postseason changes seen on magnetic resonance imaging (MRI) in youth baseball players’ elbows in an attempt to identify risk factors for pain and MRI abnormalities, with a particular focus on the current Little League guidelines. We hypothesized that MRI abnormalities would be common in pitchers with high pitch counts and poor guideline compliance. Study Design: Cohort study; Level of evidence, 2. Methods: A prospective study of Little League players aged 10 to 13 years was performed. Players were recruited prior to the start of the season and underwent bilateral elbow MRI as well as a physical examination and completed a questionnaire addressing their playing history and arm pain. At the end of the season, a repeat MRI and physical examination were performed. MRIs were read by blinded radiologists. During the season, player statistics including innings played, pitch counts, and guideline compliance were recorded. Physical examination findings and player statistics were compared between subjects with and without MRI changes utilizing chi-square and analysis of variance techniques. Results: Twenty-six players were enrolled. Despite 100% compliance with pitching guidelines, 12 players (48%) had abnormal MRI findings, and 28% experienced pain during the season. There was a significant difference in distal humeral physeal width measured pre- to postseason (1.54 vs 2.31 mm, P < .001). There was a significant loss of shoulder internal rotation during the season, averaging 11°. While pitch counts, player position, and throwing curveballs/sliders were not significantly associated with changes seen on MRI, year-round play was associated with abnormalities ( P < .05). Much lower compliance (<50%) was observed with nonenforced guidelines, including avoidance of single-sport specialization, year-round play, and throwing curveballs/sliders. Conclusion: Arm pain and MRI abnormalities of the medial elbow are common in Little League baseball players who comply with the Little League throwing guidelines, especially those playing year-round.

scholarly journals PROGRESSIVE ELBOW MRI ABNORMALITIES IN LITTLE LEAGUE BASEBALL PLAYERS ARE COMMON: A 3-YEAR LONGITUDINAL EVALUATION

2019 ◽  
Vol 7 (3_suppl) ◽  
pp. 2325967119S0006
Author(s):  
Joshua Holt ◽  
Philip Stearns ◽  
Tracey Bastrom ◽  
Morgan Dennis ◽  
Jerry Dwek ◽  
...  
Keyword(s):  
Internal Rotation ◽  
External Rotation ◽  
Mri Findings ◽  
Baseball Players ◽  
Longitudinal Evaluation ◽  
Elbow Injury ◽  
Arm Pain ◽  
Little League ◽  
Elbow Pathology

Background Significant effort has been made by multiple organizations including Little League Baseball, USA Baseball, Major League Baseball, and the American Academy of Orthopaedic Surgeons to minimize the rate of shoulder and elbow injury among Little League Baseball players. Despite this effort, recent MRI studies have shown high rates of elbow pathology in this athletic population. The purpose of the current study was to track a cohort of Little League baseball players over three years with serial examinations and MRI to determine the natural history, progression, and risk factors of previously identified elbow pathology. Methods A prospective study of Little League players who were 12 to 15 years of age was performed. All players had preseason and postseason elbow MRI performed three years prior to the current study. Players underwent repeat bilateral elbow MRI, physical examination of bilateral shoulders and elbows, a detailed assessment of throwing history, and completed a questionnaire addressing playing history and current playing status, and any arm pain. The MRI scans were read by a blinded musculoskeletal radiologist and subsequently compared to players’ prior MRI to assess for progression or resolution of previously identified pathology. Identified MRI pathology was categorized as persistent/mild, progressive/severe, or improved/resolved (Figure 1). Results All 26 players who participated in the previous single season study returned for a 3-year longitudinal assessment, representing a 100% follow-up rate. Fifteen players (58%) had dominant arm MRI pathology. 80% of MRI findings (12/15 players) were determined to be new or progressive lesions. Players with post-season MRI pathology were significantly more likely to have MRI pathology at 3-years follow-up (p<0.05). Six of the 14 players (43%) with previously normal MRI had new pathology. Year-round play was a significant predictor of tenderness to elbow palpation (p=0.027) and positive MRI findings at 3-years (p=0.047). Moderate/persistent and severe/progressive MRI findings were more often seen in players who continued to play baseball, play pitcher or catcher, and play year-round baseball (Figure 2). Dominant shoulder internal rotation was significantly less than non-dominant shoulder internal rotation amongst all players (60.3° compared with 71.2°, p=0.002). Dominant shoulder external rotation was significantly increased in players who continued to play baseball when compared with those no longer playing (109.1° versus 99.3°, p=0.012), in players playing pitcher or catcher when compared with non-pitchers/catchers (111.4° versus 100.3°, p=0.005), and in players who played year-round baseball when compared to those playing < 8 months per year (109.0° versus 100.2°, p=0.026). Conclusion/Significance Dominant elbow MRI abnormalities are common in asymptomatic Little League baseball players. Three-year longitudinal evaluation suggests that these MRI findings commonly progress, especially amongst players who continue to play baseball. Year-round play appears to impart the most notable risk to young players, with results of the current study showing increased rates of physical exam abnormalities and progressive MRI pathology. Further guidelines addressing year-round play in Little League Baseball should be established.

scholarly journals Effects of Kinesiology Taping on Shoulder Posture and Peak Torque in Junior Baseball Players with Rounded Shoulder Posture: A Pilot Study

Life ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 139
Author(s):  
Hyeong-geun Yun ◽  
Jung-Hoon Lee ◽  
Im-Rak Choi
Keyword(s):  
Pilot Study ◽  
Muscle Strength ◽  
Internal Rotation ◽  
External Rotation ◽  
Peak Torque ◽  
Crossover Design ◽  
Baseball Players ◽  
Shoulder Peak ◽  
Kinesiology Tape ◽  
To Receive

Rounded shoulder posture (RSP) causes an imbalance of the adjacent joints due to the malalignment of the shoulder joint, and thus affects the strength of the muscles surrounding the shoulder. This study aimed to investigate the effect of rounded shoulder taping (RST) on shoulder posture and muscle strength in junior baseball players. Nineteen junior baseball players participated in the study, which used a crossover design at an interval of 1 week. The participants were randomized to receive rounded shoulder taping (RST) and sham kinesiology taping (SKT) using kinesiology tape. RSP was measured using two 12-inch combination squares, and shoulder peak torques were measured by isokinetic equipment. The results showed that RST led to significant changes in RSP (p < 0.05), but no significant changes were observed with SKT (p < 0.05). RST led to significant changes in the peak torques of external rotation and internal rotation of the shoulder (p < 0.05), but no significant changes were observed with SKT (p < 0.05). These results suggest that RST could help to correct RSP and improve peak torque of external and internal rotation of the shoulders of junior baseball players with RSP.

Humeral Retrotorsion and Glenohumeral Motion in Youth Baseball Players Compared With Age-Matched Nonthrowing Athletes

2016 ◽  
Vol 45 (2) ◽  
pp. 454-461 ◽  
Author(s):  
Elliot M. Greenberg ◽  
J. Todd R. Lawrence ◽  
Alicia Fernandez-Fernandez ◽  
Philip McClure
Keyword(s):  
Range Of Motion ◽  
External Rotation ◽  
Pearson Correlation ◽  
Sports Participation ◽  
Baseball Players ◽  
Shoulder Range Of Motion ◽  
Youth Baseball ◽  
Shoulder Motion ◽  
Age Range ◽  
Side Asymmetry

Background: Baseball players exhibit a more posteriorly oriented humeral head in their throwing arm. This is termed humeral retrotorsion (HRT) and likely represents a response to the stress of throwing. This adaptation is thought to occur while the athlete is skeletally immature, however currently there is limited research detailing how throwing activity in younger players influences the development of HRT. In addition, it is presently unclear how this changing osseous orientation may influence shoulder motion within young athletes. Purpose: To determine the influence of throwing activity and age on the development of side-to-side asymmetry in HRT and shoulder range of motion (ROM). Study Design: Cross-sectional study; Level of evidence, 3. Methods: Healthy athletes (age range, 8-14 years) were categorized into 2 groups based upon sports participation; throwers (n = 85) and nonthrowers (n = 68). Bilateral measurements of HRT, shoulder external rotation (ER), internal rotation (IR), and total range of motion (TROM) at 90° were performed using diagnostic ultrasound and a digital inclinometer. Side-to-side asymmetry (dominant minus nondominant side) in HRT and in shoulder ER, IR, and TROM were assessed. Statistical analysis was performed with 2-way analysis of variance and Pearson correlation coefficients. Results: Throwers demonstrated a larger degree of HRT on the dominant side, resulting in greater asymmetry compared with nonthrowers (8.7° vs 4.8°). Throwers demonstrated a gain of ER (5.1°), a loss of IR (6.0°), and no change in TROM when compared with the nondominant shoulder. Pairwise comparisons identified altered HRT and shoulder ROM in all age groups, including the youngest throwers (age range, 8-10.5 years). A positive correlation existed between HRT and ER ROM that was stronger in nonthrowers ( r = 0.63) than in throwers ( r = 0.23), while a negative correlation existed with IR that was stronger in throwers ( r = −0.40) than in nonthrowers ( r = −0.27). Conclusion: Throwing activity causes adaptive changes in HRT and shoulder ROM in youth baseball players at an early age. Other factors in addition to HRT influence shoulder motion within this population.

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