Infraspinatus

BACKGROUND: Rotator cuff tears have been repaired using the transosseous method for decades. The direct suture (DS) technique has been widely used for rotator cuff tears; however, the retear rate is relatively high. Suture anchors are now used frequently for rotator cuff repair (RCR) in accordance with recent developments in materials. However, polyether ether ketone (PEEK) may still cause complications such as the formation of cysts and osteophytes. Some studies have developed the inlay suture (IS) technique for RCR...

AIMS: Rotator cuff (RC) injuries are characterized by tendon rupture, muscle atrophy, retraction, and fatty infiltration, which increase injury severity and jeopardize adequate tendon repair. Epigenetic drugs, such as histone deacetylase inhibitors (HDACis), possess the capacity to redefine the molecular signature of cells, and they may have the potential to inhibit the transformation of the fibro-adipogenic progenitors (FAPs) within the skeletal muscle into adipocyte-like cells, concurrently enhancing the myogenic potential of the satellite cells...

Background Arthroscopy in diagnosing a rotator cuff injury has surgical and anaesthesia-related risks. Magnetic resonance imaging (MRI), a non-invasive procedure, is expensive, and lacks dynamic components making it less favourable. Clinical examination narrows the diagnosis, but lacks diagnostic accuracy due to overlap of clinical signs and symptoms. We aimed to determine the diagnostic accuracy of clinical examination and MRI in rotator cuff tears by correlating it with arthroscopy. Methods This prospective, cross-sectional validation study included patients (N=28) with shoulder pain with clinical characteristics suggestive of rotator cuff tears...

The infraspinatus muscle (IS) makes a minor contribution to lateral rotation of the arm but mainly serves to stabilize the glenohumeral (GH) joint as part of the rotator cuff. Although reports of variations in the rotator cuff muscles have been documented previously, specific discussions of IS variants are lacking. In this report, we present a novel case of an accessory muscle in the infraspinous fossa and its relationship to the IS, which was normally located. We describe the observed physical features of the muscles and their innervation patterns...

Objectives : The objective is to compare stiffness changes around the shoulder muscles between pitchers and position players after throwing overhead using shear wave elastography (SWE) in relation to throwing motion analysis and muscle strength. Methods : A total of 32 male college baseball players (12 pitchers and 20 position players) were observed throwing 20 times, and SWE was performed to evaluate 13 shoulder muscle items-tendons (supraspinatus, infraspinatus, subscapularis, and teres minor), muscles (supraspinatus, infraspinatus [transverse and oblique part], teres minor, lower trapezius, latissimus dorsi, and pectoralis minor), and capsules (posterior and posteroinferior)...

Incorporating detailed muscle architecture aspects into computational models can enable researchers to gain deeper insights into the complexity of muscle function, movement, and performance. In this study, we employed histological, multiphoton image processing, and finite element method techniques to characterise the mechanical dependency on the architectural behaviour of supraspinatus and infraspinatus mouse muscles. While mechanical tests revealed a stiffer passive behaviour in the supraspinatus muscle, the collagen content was found to be two times higher in the infraspinatus...

PURPOSE: The purpose of this study was to evaluate the clinical and radiographic outcomes of an all-arthroscopic rotator cuff repair technique involving muscle advancement and double-layer lasso loop (DLLL) repair for massive, retracted posterosuperior cuff tears. METHODS: This is a retrospective case series of patients with massive, retracted posterosuperior cuff tears who underwent the all-arthroscopic muscle advancement technique from March 2017 to September 2021, with minimum follow-up of 12 months...

BACKGROUND: A strong body of literature has been published outlining muscle activity differences during sports performance in groups of overhead athletes. However, there are limited studies that have directly compared the muscle activity in overhead athletes with and without history of shoulder injury during functional everyday tasks. PURPOSE: This study aimed to identify muscle activities across fourteen upper extremity and core muscles during three functional everyday movements in athletes with and without history of shoulder injury...

BACKGROUND: The rotator cable functions as a stress and/or load transfer structure. Some studies suggested that a disruption of the cable negatively affects shoulder function and tendon integrity in patients with rotator cuff tears, while others found no functional impairment regardless of rotator cable tear severity. Although anatomical studies have identified distinct regions within the rotator cuff muscles, the strain distribution within the articular sides of the rotator cuff tendons that results from the tension in each region remains unknown...

Background The benefits of vitamin D encompass the augmentation of rotator cuff healing, the enhancement of bone mineral density (BMD), and the fortification of skeletal muscle strength. The vitamin D deficiency in Asian countries appears to be more severe compared to their Western counterparts. This study aims to ascertain the relationship between rotator cuff tears and vitamin D levels in the urban Thai elderly demographic. Our hypothesis posits that vitamin D deficiency will exhibit an association with the occurrence of rotator cuff tears...

BACKGROUND: Superior capsular reconstruction (SCR) and lower trapezius tendon transfer (LTT) have recently been used to manage irreparable posterosuperior rotator cuff tears (PSRCTs). There has been a paucity of comparative biomechanical considerations between the 2 procedures. PURPOSE: To compare the glenohumeral stability and biomechanical properties between SCR and LTT in PSRCTs involving the entire infraspinatus tendon region. STUDY DESIGN: Controlled laboratory study...

BACKGROUND: Shoulder disorders, particularly rotator cuff tears, are prevalent musculoskeletal conditions related to aging. Although the widely used suture anchor technique provides strong mechanical support to the tendon, it is associated with a risk of postoperative tendon retearing. The conventionally used titanium alloys can affect the interpretation of magnetic resonance imaging. Degradable magnesium alloys possess excellent biocompatibility, similar mechanical property to the bone, and stimulating bone formation ability from Mg2+ ...

Objectives . Shoulder protraction is frequently seen in office workers because of working with excessive trunk flexion for a long time. This study aimed to compare the effectiveness of stabilization exercises (SE) given in addition to office exercises (OE). Methods . Sixty office workers with shoulder protraction were divided into SE + OE ( n =  30) and OE ( n =  30) groups by stratified random sampling for 8 weeks and followed up for 4 weeks. Shoulder protraction was assessed with a caliper, muscle strength with a hand-held dynamometer, proprioception with an isokinetic dynamometer, vibration sense with a vibrometer and upper extremity functional performance with the closed kinetic chain upper extremity stability test...

Background: Team handball involves a tremendous amount of shoulder motion with high forces during repeated extended external range of motion. This causes shoulder complaints and overuse injuries. While eccentric training for the lower extremity shows preventive effects by improving strength, range of motion and fascicle length, there is a research gap for the shoulder joint and for advanced tissue characterization using diffusion tensor imaging. Objectives: To investigate the effects of 6-week eccentric isokinetic resistance training on strength, flexibility, and fiber architecture characteristics of the external rotators compared to an active control group in junior male handball players...

BACKGROUND: Constitutional static posterior humeral decentering (type C1 according to ABC Classification) has been recognized as a pre-osteoarthritic deformity that may lead to early-onset posterior decentering osteoarthritis at a young age. Therefore, it is important to identify possible associations of this pathologic shoulder condition to find more effective treatment options. PURPOSE: To perform a comprehensive analysis of all parameters reported to be associated with a C1 shoulder-including the osseous shoulder morphology, scapulothoracic orientation, and the muscle volume of the shoulder girdle in a single patient cohort...

Rotator cuff (RC) and long head of the biceps tendon (LHBT) tears are common shoulder problems presented to the orthopedic clinic. The aim of this study was to assess the association between RC and LHBT tears among a Saudi population sample. A total of 243 patients who were diagnosed with shoulder pain due to RC or LHBT tear between 2016 and 2018 using a magnetic resonance imaging scan were included in this study. Females comprised 66% of the sample, and 59% (n = 143) of the shoulders were on the right side...

BACKGROUND: Muscle edema formation and inflammatory processes are early manifestations of acute rotator cuff lesions in sheep. Histological analysis of affected muscles revealed edema formation, inflammatory changes, and muscle tissue disruption in MRs. HYPOTHESIS: Edema contributes to inflammatory reactions and early muscle fiber degeneration before the onset of fatty infiltration. STUDY DESIGN: Controlled laboratory study. METHODS: Osteotomy of the greater tuberosity, including the insertion of the infraspinatus tendon, was performed on 14 sheep...

BACKGROUND: Recent scientific work shows that the most common injuries in CrossFit© occur in the shoulder joint. This paper aims to provide a review of shoulder pathologies in a young CrossFit© cohort via MRI and clinical examination. METHODS: A survey was conducted in 13 CrossFit "boxes" in Germany, in which athletes with recurrent shoulder pain could report for a clinical examination and MRI diagnostic. Fifty-one CrossFit athletes with chronic shoulder pain agreed to participate in the study and were then examined physically and by MRI...

BACKGROUND: Recent studies have focused on the deep layer in delaminated rotator cuff tears. However, no studies have discussed the relationship between repair success and the properties of the deep layer. Herein, we aimed to analyze the intraoperative repair tension of the deep layer with respect to clinical outcomes and repair integrity and to evaluate the clinical results of delaminated rotator cuff tears after dual layer-specific repair. METHODS: A total of 202 patients with delaminated rotator cuff tears had undergone dual layer-specific suture bridge repair; the mean follow-up duration was 28...

BACKGROUND: One proposed mechanism of rotator cuff disease is scapular motion impairments contributing to rotator cuff compression and subsequent degeneration. PURPOSE: To model the effects of scapular angular deviations on rotator cuff tendon proximity for subacromial and internal mechanical impingement risk during scapular plane abduction. STUDY DESIGN: Descriptive laboratory study. METHODS: Three-dimensional bone models were reconstructed from computed tomography scans obtained from 10 asymptomatic subjects and 9 symptomatic subjects with a clinical presentation of impingement syndrome...