scholarly journals Kinematic Differences between Two Types of Forward Elevations of the Shoulder Joint: Flexion and Reaching Elevation

2020 ◽  
Vol 14 (1) ◽  
pp. 15-25
Author(s):  
Ryo Sahara ◽  
Junichiro Hamada ◽  
Kunio Yoshizaki ◽  
Kazuhiro Endo ◽  
Daisuke Segawa ◽  
...  
Keyword(s):  
Rotator Cuff ◽  
Elbow Joint ◽  
Glenohumeral Joint ◽  
External Rotation ◽  
Three Dimensional ◽  
Coronal Plane ◽  
Shoulder Flexion ◽  
Joint Flexion ◽  
Motion Plane ◽  
Teres Minor

Background: Extension of the elbow joint is maintained during shoulder flexion. In contrast, the arm starts from the flexed position of the elbow joint and the joint gradually extends during reaching elevation. Objectives: This study aimed to compare the kinematic elements and electromyographic (EMG) activities of the rotator cuff muscles between flexion and reaching elevation. Methods: The study included 10 healthy young men. (average age, 21.5 ± 3.4 years), and measurements were performed on their dominant arms. A three-dimensional motion analyzer was used to record the following elements during shoulder flexion and reaching elevation: the angles of glenohumeral joint elevation and scapular upward rotation, scapulohumeral rhythm, external rotation of the humerus, and glenohumeral plane shifting from the coronal plane. The EMG activities in the supraspinatus, infraspinatus, subscapularis, and teres minor were recorded simultaneously. Results: The plane of reaching elevation was retained at 60° from the coronal plane. The glenohumeral planes (P < 0 .01) and the external rotation angles of the humerus below 90° of elevation (P < 0.05) were significantly different between both the motions. The EMG activities in the supraspinatus (P < .01), infraspinatus (P < 0.05), and teres minor (P < 0.01) were significantly lower while reaching elevation than those during flexion. Conclusion: The motion plane at 60° from the coronal plane, movement of the humeral external rotation, and EMG activities of the rotator cuff muscles were different during reaching elevation and shoulder flexion.

Chronic Adaptations of the Posterior Rotator Cuff in Professional Pitchers

2021 ◽  
pp. 036354652098868
Author(s):  
Stephen J. Thomas ◽  
Justin Cobb ◽  
Scott Sheridan ◽  
Joseph Rauch ◽  
Ryan W. Paul
Keyword(s):  
Soft Tissue ◽  
Rotator Cuff ◽  
Internal Rotation ◽  
External Rotation ◽  
Negative Relationship ◽  
Muscle Thickness ◽  
Pennation Angle ◽  
Muscle Architecture ◽  
Infraspinatus Muscle ◽  
Teres Minor

Background: Because of the large forces and high frequency of throwing, the upper extremity experiences repetitive stresses that lead to acute and chronic adaptations. While the importance of pennation angle and muscle thickness as predictors of muscle force production has been shown in other populations and other joints, there has been little research done that examines these variables in the shoulders of baseball players. Purpose: (1) To examine the chronic effect pitching has on the rotator cuff muscle architecture (pennation angle and muscle thickness) in healthy professional baseball pitchers, and (2) to examine the correlation between muscle architecture and clinical measures of strength and range of motion (ROM). Study Design: Cross-sectional study; Level of evidence, 3. Methods: Twenty-eight healthy professional pitchers were recruited during the 2019 spring training. Internal rotation (IR) and external rotation (ER) strength were measured with a handheld dynamometer and IR and ER ROM were measured with an inclinometer. A diagnostic ultrasound machine was utilized to capture images of humeral retroversion, as well as the pennation angle and muscle thickness of the infraspinatus and teres minor muscles. ImageJ software was used to quantify the pennation angle and muscle thickness. Results: There were no significant differences between the dominant and nondominant arms for ER or IR strength. Also, no pennation angle and muscle thickness differences were found between the dominant and nondominant arms. A weak positive relationship between infraspinatus muscle thickness (superficial and total) and ER strength ( P = .016, R = 0.287 and P = .009, R = 0.316) and a moderate negative relationship between soft tissue glenohumeral internal rotation deficit (GIRD) and the bilateral difference of the teres minor deep pennation angle ( R = −0.477, P = .008) were observed. No other significant relationships were noted. Conclusion: Our results are contrary to current literature as we expected to see a stronger dominant arm, with a larger pennation angle and greater muscle thickness. Interestingly, we found that ER strength was positively related to only the thickness of the infraspinatus muscle, and that soft tissue GIRD was positively related to only the side-to-side adaptation of the pennation angle within the deep portion of the teres minor. This suggests that when posterior shoulder tightness occurs, specifically the architecture of the teres minor muscle is involved. However, the organization to which these players belonged has a very extensive training protocol throughout the year that emphasizes bilateral training during a large majority of the exercises. Therefore, the results may not be generalizable to all professional players.

scholarly journals Anatomy and Biomechanic of the Shoulder

2019 ◽  
Vol 7 (11_suppl6) ◽  
pp. 2325967119S0046
Author(s):  
Troydimas Panjaitan
Keyword(s):  
Rotator Cuff ◽  
Humeral Head ◽  
Glenohumeral Joint ◽  
External Rotation ◽  
Central Component ◽  
Subscapularis Tendon ◽  
Glenoid Fossa ◽  
Greater Tuberosity ◽  
Glenohumeral Ligaments ◽  
Shoulder Complex

The shoulder is one of the most complex joints of the human body. Consequently, they are susceptible to injury and degeneration. Mechanical shoulder pathology typically results when overuse, extremes of motion, or excessive forces overwhelm intrinsic material properties of the shoulder complex resulting in tears of the rotator cuff, capsule, and labrum. The fundamental central component of the shoulder complex is the glenohumeral joint. It has a ball-and-socket configuration with a surface area ratio of the humeral head to glenoid fossa of about 3:1 with an appearance similar to a golf ball on a tee. Overall, there is minimal bony covering and limited contact areas that allow extensive translational and rotational ability in all three planes. The glenohumeral joint has 2 groups of stabilizers, which are static (passive) and dynamic (active) restrains. Static stabilizers include the concavity of the glenoid fossa, glenoid fossa retroversion and superior angulation, glenoid labrum, the joint capsule, and glenohumeral ligaments, and a vacuum effect from negative intra-articular pressure. Dynamic stabilization is merely the coordinated contraction of the rotator cuff muscles that create forces that compress the articular surfaces of the humeral head into the concave surface of the glenoid fossa. During upper extremity movement, the effects of static stabilizers are minimized and dynamic or active stabilizers become the dominant forces responsible for glenohumeral stability The simple act of arm elevation is a complex task that occurs via the combination of glenohumeral and scapulothoracic motion, together known as scapulohumeral rhythm. In the first 1200, glenohumeral arm abduction, the supraspinatus and deltoid work together and create a force couple that promotes stability, while raising the arm (deltoid contraction). In addition, the humerus must undergo 450 external rotation to not only clear the greater tuberosity posteriorly but also loosen the inferior glenohumeral ligament (IGHL) to allow maximum elevation. There are several anatomical updates regarding the rotator cuff and capsular footprint. The footprint of the supraspinatus on the greater tuberosity is much smaller than previously believed, and this area of the greater tuberosity is actually occupied by a substantial amount of the infraspinatus. The superior-most insertion of the subscapularis tendon extends a thin tendinous slip, which attaches to the fovea capitis of the humerus. The teres minor muscle inserts to the lowest impression of the greater tuberosity of the humerus and additionally inserts to the posterior side of the surgical neck of the humerus.

Three-Dimensional Scapular Kinematics during the Throwing Motion

2008 ◽  
Vol 24 (1) ◽  
pp. 24-34 ◽  
Author(s):  
Kristin E. Meyer ◽  
Erin E. Saether ◽  
Emily K. Soiney ◽  
Meegan S. Shebeck ◽  
Keith L. Paddock ◽  
...  
Keyword(s):  
Internal Rotation ◽  
Glenohumeral Joint ◽  
External Rotation ◽  
Angular Position ◽  
Three Dimensional ◽  
Low Velocity ◽  
Dynamic Activity ◽  
Motion Data ◽  
Asymptomatic Subjects ◽  
Scapular Motion

Proper scapular motion is crucial for normal shoulder mechanics. Scapular motion affects glenohumeral joint function during throwing, yet little is known about this dynamic activity. Asymptomatic subjects (10 male and 10 female), ages 21 to 45, were analyzed. Electromagnetic surface sensors on the sternum, acromion, and humerus were used to collect 3-D motion data during three trials of low-velocity throwing. Scapular angular position data were described for five predetermined events throughout the throw corresponding with classic descriptions of throwing phases, and trial-to-trial reliability was determined. ANOVA compared scapular angles across events. Subjects demonstrated good to excellent reliability between trials of the throw (ICC 0.74–0.98). The scapula demonstrated a pattern of external rotation, upward rotation (peak of approx. 40°), and posterior tilting during the initial phases of the throw, progressing into internal rotation after maximum humeral horizontal abduction. During the arm acceleration phase, the scapula moved toward greater internal rotation and began anteriorly tilting. At maximum humeral internal rotation, the scapula ended in internal rotation (55°), upward rotation (20°), and anterior tilting (3°).

scholarly journals A three dimensional multiplane kinematic model for bilateral hind limb gait analysis in cats

2018 ◽  
Author(s):  
Nathan P. Brown ◽  
Gina E. Bertocci ◽  
Kimberly A. Cheffer ◽  
Dena R. Howland
Keyword(s):  
Gait Analysis ◽  
Hind Limb ◽  
Sagittal Plane ◽  
External Rotation ◽  
Kinematic Model ◽  
Three Dimensional ◽  
Joint Angles ◽  
Plane Model ◽  
Flexion Extension ◽  
Joint Flexion

AbstractBackground: Kinematic gait analysis is an important noninvasive technique used for quantitative evaluation and description of locomotion and other movements in healthy and injured populations. Three dimensional (3D) kinematic analysis offers additional outcome measures including internal-external rotation not characterized using sagittal plane analysis techniques.Methods: The objectives of this study were to 1) develop and evaluate a 3D hind limb multiplane kinematic model for gait analysis in cats using joint coordinate systems, 2) implement and compare two 3D stifle (knee) prediction techniques, and 3) compare flexion-extension determined using the multiplane model to a sagittal plane model. Walking gait was recorded in 3 female adult cats (age = 2.9 years, weight = 3.5 ± 0.2 kg). Kinematic outcomes included flexion-extension, internal-external rotation, and abduction-adduction of the hip, stifle, and tarsal (ankle) joints.Results: Each multiplane stifle prediction technique yielded similar findings. Joint angles determined using markers placed on skin above bony landmarks in vivo were similar to joint angles determined using a feline hind limb skeleton in which markers were placed directly on landmarks ex vivo. Differences in hip, stifle, and tarsal joint flexion-extension were demonstrated when comparing the multiplane model to the sagittal plane model.Conclusions: This multiplane cat kinematic model can predict joint rotational kinematics as a tool that can quantify frontal, transverse, and sagittal plane motion. This model has multiple advantages given its ability to characterize joint internal-external rotation and abduction-adduction. A further, important benefit is greater accuracy in representing joint flexion-extension movements.

scholarly journals Electromyographical Comparison of Four Common Shoulder Exercises in Unstable and Stable Shoulders

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Aaron Sciascia ◽  
Nina Kuschinsky ◽  
Arthur J. Nitz ◽  
Scott D. Mair ◽  
Tim L. Uhl
Keyword(s):  
Rotator Cuff ◽  
High Activity ◽  
Shoulder Instability ◽  
Glenohumeral Joint ◽  
External Rotation ◽  
Emg Activity ◽  
Moderate Activity ◽  
Serratus Anterior ◽  
Maximum Voluntary Isometric Contraction ◽  
Push Up

This study examines if electromyographic (EMG) amplitude differences exist between patients with shoulder instability and healthy controls performing scaption, prone horizontal abduction, prone external rotation, and push-up plus shoulder rehabilitation exercises. Thirty nine subjects were categorized by a single orthopedic surgeon as having multidirectional instability (n=10), anterior instability (n=9), generalized laxity (n=10), or a healthy shoulder (n=10). Indwelling and surface electrodes were utilized to measure EMG activity (reported as a % of maximum voluntary isometric contraction (MVIC)) in various shoulder muscles during 4 common shoulder exercises. The exercises studied effectively activated the primary musculature targeted in each exercise equally among all groups. The serratus anterior generated high activity (50–80% MVIC) during a push-up plus, while the infraspinatus and teres major generated moderate-to-high activity (30–80% MVIC) during both the prone horizontal and prone external rotation exercises. Scaption exercise generated moderate activity (20–50% MVIC) in both rotator cuff and scapular musculature. Clinicians should feel confident in prescribing these shoulder-strengthening exercises in patients with shoulder instability as the activation levels are comparable to previous findings regarding EMG amplitudes and should improve the dynamic stabilization capability of both rotator cuff and scapular muscles using exercises designed to address glenohumeral joint instability.

Ligamentous Restraints to External Rotation of the Humerus in the Late-Cocking Phase of Throwing

2000 ◽  
Vol 28 (2) ◽  
pp. 200-205 ◽  
Author(s):  
John E. Kuhn ◽  
Michael J. Bey ◽  
Laura J. Huston ◽  
Ralph B. Blasier ◽  
Louis J. Soslowsky
Keyword(s):  
Rotator Cuff ◽  
Glenohumeral Joint ◽  
External Rotation ◽  
Coracoacromial Ligament ◽  
Glenohumeral Ligament ◽  
Coracohumeral Ligament ◽  
Potential Source ◽  
Glenohumeral Ligaments ◽  
Inferior Glenohumeral Ligament ◽  
Glenohumeral Capsule

The late-cocking phase of throwing is characterized by extreme external rotation of the abducted arm; repeated stress in this position is a potential source of glenohumeral joint laxity. To determine the ligamentous restraints for external rotation in this position, 20 cadaver shoulders (mean age, 65 16 years) were dissected, leaving the rotator cuff tendons, coracoacromial ligament, glenohumeral capsule and ligaments, and coracohumeral ligament intact. The combined superior and middle glenohumeral ligaments, anterior band of the inferior glenohumeral ligament, and the entire inferior glenohumeral ligament were marked with sutures during arthroscopy. Specimens were mounted in a testing apparatus to simulate the late-cocking position. Forces of 22 N were applied to each of the rotator cuff tendons. An external rotation torque (0.06 N m/sec to a peak of 3.4 N m) was applied to the humerus of each specimen with the capsule intact and again after a single randomly chosen ligament was cut (N 5 in each group). Cutting the entire inferior glenohumeral ligament resulted in the greatest increase in external rotation (10.2° 4.9°). This was not significantly different from sectioning the coracohumeral ligament (8.6° 7.3°). The anterior band of the inferior glenohumeral ligament (2.7° 1.5°) and the superior and middle glenohumeral ligaments (0.7° 0.3°) were significantly less important in limiting external rotation.

scholarly journals How common is fatty infiltration of the teres minor in patients with shoulder pain? A review of 7,367 consecutive MRI scans

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
William R. Aibinder ◽  
Derrick A. Doolittle ◽  
Doris E. Wenger ◽  
Joaquin Sanchez-Sotelo
Keyword(s):  
Rotator Cuff ◽  
Shoulder Pain ◽  
Muscle Atrophy ◽  
External Rotation ◽  
Reverse Shoulder Arthroplasty ◽  
Fatty Infiltration ◽  
Deltoid Muscle ◽  
Rotator Cuff Tears ◽  
Shoulder Mri ◽  
Teres Minor

Abstract Purpose The teres minor is particularly important for activities that require external rotation in abduction in the settings of both rotator cuff tears and reverse shoulder arthroplasty. This study sought to assess the incidence of teres minor fatty infiltration in a large cohort of consecutive patients evaluated with shoulder MRI for shoulder pain and to identify all associated pathologies in an effort to determine the various potential etiologies of teres minor involvement. Methods A retrospective review of 7,376 non-contrast shoulder MRI studies performed between 2010 and 2015 were specifically evaluated for teres minor fatty infiltration. Studies were reviewed by two fellowship trained musculoskeletal radiologists. Muscle atrophy was graded on a 3-point scale according to Fuchs and Gerber. The remaining rotator cuff tendons and muscles, biceps tendon, labrum, and joint surfaces were assessed on MRI as well. Results In this series, 209 (2.8%) shoulders were noted to have fatty infiltration of the teres minor. The rate of isolated fatty infiltration of the teres minor was 0.4%. Concomitant deltoid muscle atrophy was common, and occurred in 68% of the shoulders with fatty infiltration of the teres minor. Tearing of the teres minor tendon was extremely rare. Conclusion Fatty infiltration of the teres minor can occur in isolation, be associated with deltoid muscle atrophy only, or occur in the setting of rotator cuff full tears. Thus, fatty infiltration of the teres minor may be related to a neurologic process or disuse. Further long term longitudinal studies are necessary to be elucidate the etiologies. Level of Evidence Level IV.

scholarly journals Quantitative Evaluation of Shoulder Joint Function to Reproduce Results of Clinical Tests by Therapist

2013 ◽  
Vol 25 (6) ◽  
pp. 983-991 ◽  
Author(s):  
Noritaka Sato ◽  
◽  
Keita Kamada ◽  
Yuki Hiramatsu ◽  
Kazunori Yamazaki ◽  
...  
Keyword(s):  
Quantitative Evaluation ◽  
Shoulder Joint ◽  
Evaluation System ◽  
Evaluation Method ◽  
Glenohumeral Joint ◽  
External Rotation ◽  
Three Dimensional ◽  
Evaluation Methods ◽  
Initial Position ◽  
Joint Function

The final aim of this research is to develop a quantitative evaluation system of shoulder joint function using a three-dimensional force display robot. In this paper, we proposed quantitative evaluation methods by which the results equivalent to the results of tests by a therapist can be obtained. The quantitative evaluation methods can be installed in the robot. We focus on two shoulder joint functions. One is stability and the other is cooperativeness. Two experiments were carried out to develop quantitative evaluation methods of shoulder joint function. In the experiments, subject’s forces were measured during the tests by the therapist. On the basis of the experimental results, we proposed a stability evaluation method using a regression equation of glenohumeral joint instability from the ratios between the right and the left subject’s force in the initial position during abduction, external rotation and horizontal abduction motion. Moreover, we proposed a cooperativeness evaluation method by detecting two thresholds related to sustainability of subject’s force.

scholarly journals Biomechanical characteristics of scapula and glenohumeral movements during pitching motion in injury-prone college baseball pitchers

2021 ◽  
Author(s):  
Koji Miyashita ◽  
Sentaro Koshida ◽  
Taro Koyama ◽  
Kenicihro Ota ◽  
Yusuke Tani ◽  
...  
Keyword(s):  
Sports Medicine ◽  
High Speed ◽  
Glenohumeral Joint ◽  
External Rotation ◽  
Three Dimensional ◽  
Control Group ◽  
Shoulder Injuries ◽  
Pitching Motion ◽  
College Baseball ◽  
Baseball Pitchers

Coordination of glenohumeral and scapular movements plays an important role in the injury prevention of baseball pitchers. However, there is no objective data establishing the direct relationship between pitching injuries and associated glenohumeral and scapular movements. Therefore, the objectives of the present study were to demonstrate biomechanical differences in scapular and glenohumeral movements during pitching between injury-prone pitchers and healthy college baseball pitchers. Thirty collegiate baseball pitchers were classified into two groups according to their injury status: injury-prone group (N=15, 20.7±1.4 years, 180.1±6.5 cm, 78.9±5.4 kg) and control group (N=15, 20.9±1.1 years, 177.1±6.6 cm, 72.3±6.7 kg). We obtained the pitching motion data using the three-dimensional motion analysis technique with four high-speed cameras. The horizontal abduction angles of the glenohumeral joint during cocking and acceleration phases were significantly greater in injury-prone pitchers [19.0° (95% CI: 14.4–23.6) at foot contact, −4.0° (95% CI: −7.7 to −0.2) at maximum external rotation (MER), and −0.3° (95% CI: −4.8 to −4.2) at ball release] than in healthy controls [11.7 °(95%CI:7.1 to 16.3) at foot contact, −10.0°(95%CI: −13.7 to −6.3) at MER, and −6.9°(95%CI: −11.4 to −2.4)]( p <0.01). In addition, the external rotation angle (ER) of the scapula at MER was significantly greater in the injury-prone group [−0.1° (95% CI: −5.0 to 4.8)] than in the control group [−12.3° (95% CI: −17.2 to −7.4)] (p<0.01), but there was no difference in the scapular ER during foot contact between the two groups. These results suggests that injury-prone pitchers have less internal rotation of the scapula and more horizontal abduction of the glenohumeral joint during cocking and acceleration phases. Therefore, sports medicine practitioners may need to pay more attention to coordination of scapular and glenohumeral movements during the cocking and acceleration phases of pitching for prevention of shoulder injuries.

scholarly journals GANGGUAN MANSET ROTATOR SENDI BAHU Suatu tinjauan anatomik

2014 ◽  
Vol 6 (3) ◽  
Author(s):  
George N. Tanudjaja
Keyword(s):  
Rotator Cuff ◽  
Range Of Motion ◽  
Shoulder Pain ◽  
Glenohumeral Joint ◽  
Spontaneous Pain ◽  
Supraspinatus Muscle ◽  
Joint Structure ◽  
Wide Range ◽  
Teres Minor

Abstract: Rotator cuff of glenohumeral joint is a group of muscles and their tendons which surrounds and protects the wholeness of the glenohumeral joint and functions as a shoulder rotator. Shoulder pain is commonly found and is mostly caused by tendinitis of the rotator cuff or subacromial bursitis. There are four important muscles of this rotator cuff: supraspinatus, infraspinatus, teres minor, and subscapularis (SITS) muscles. Among them, the most troublesome is the tendon of supraspinatus muscle that functions as a sheet as well as the abductor of glenohumeral joint. Therefore, tendinitis of this muscle is associated with spontaneous pain and disturbance in lifting the superior extremity. This cuff structure shows that tendons of the SITS muscles together with the capsule of genohumeral joint and the joint structure itself enable a very wide range of motion with a consequence of being troubled easily.Keywords: glenohumeral, rotator cuf, tendon, jointAbstrak: Manset rotator sendi bahu adalah sekelompok otot dan tendonnya yang mengelilingi dan menjaga keutuhan articulatio genohumerale dengan fungsi lain sebagai rotator brachium. Nyeri bahu sering ditemukan dan umumnya disebabkan oleh tendinitis manset rotator atau bursitis subacromiale. Di antara keempat tendines, yang tersering mengalami gangguan yaitu tendon m. supraspinatus yang selain sebagai pembungkus juga berfungsi sebagai abduktor articulatio glenohumerale sehingga selain nyeri spontan juga ditemukan kesulitan mengangkat membrum superior. Struktur manset ini menunjukkan bahwa tendines keempat otot tersebut bergabung dengan capsula articularis genohumerale dengan struktur sendinya yang memungkinkan pergerakan bahu yang sangat luas tetapi dengan konsekuensi akan lebih mudah terjadi gangguan.Kata kunci: sendi bahu, manset rotator, tendon, articulatio

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