Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “SCAPULA”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 937 records · Page 52Linked to original sources
PubMed1990

Electromyogram (EMG) recordings from the subscapularis muscle: description of a technique.

Operative treatments for recurrent dislocation of the shoulder usually focus on the subscapularis muscle because it is supposed to contribute to the joint stability. It is of clinical interest to record the EMG from the subscapularis muscle in order to interpret its function. The purpose of the present study was to describe a safe and reliable route to reach the muscle, deeply located between the scapula and the thoracic cage, with fine-wire EMG electrodes. Twenty-four shoulders were investigated in 12 volunteers. A hypodermic needle containing bipolar fine-wire electrodes was inserted in the posterior axillary line with the subjects in the supine position, and the arm held in an abducted and externally rotated position. Three criteria confirmed the location of the electrodes: experience of periosteal pain when the needle reached the costal surface of the scapula, drawing-in of the wires 3-4 cm when the subject adducted his arm, thereby rotating his scapula downward, and raw EMG recorded during typical movements. Additionally, in four shoulders, the electrode location was checked with computed tomography. There were no complications from this technique, and the subjects felt no pain from the fine-wire electrodes during arm movements. We conclude that the described technique is a safe and reliable method of reaching the subscapularis muscle with EMG electrodes.

Adult↗
PubMed1987

Anatomical basis of modern thoracotomies: the latissimus dorsi and the "serratus anterior-rhomboid" complex.

The latissimus dorsi and the "serrato-rhomboid" complex are the muscles most often involved in present-day thoracotomies for lung surgery. The present anatomic study emphasizes: the continuity between the serratus anterior and the rhomboid levator scapulae mass as a wide muscular sheet with a deep common fascia, extending the serrato-thoracic space (of Gillis) to the vertebral column as the rhomboserrato-thoracic space (the levator scapulae is situated higher up, above the ordinary thoracotomy); the presence of a "composite fascia" in the posterior angle between the seratus anterior and the rhomboid; the long costal attachment area and the presence of two differently oriented layers for the muscular digitations of the middle and inferior parts of the serratus anterior. With a rich vascular supply from multiple sources, the serratus anterior and latissimus dorsi are two large flat muscles with a single longitudinal nervous pedicle proceeding from the brachial plexus. To avoid esthetic (winged scapula) and functional sequelae, it is imperative to safeguard this single innervation as far as possible : by halting division of the serratus anterior before reaching its neurovascular pedicle in lateral or anterolateral thoracotomy, and by transecting the latissimus dorsi very low down in standard postero-lateral thoracotomy. The other muscles are simply freed and retracted.

Humans↗
PubMed1998

The cat vertebral column: stance configuration and range of motion.

This study examined the configuration of the vertebral column of the cat during independent stance and in various flexed positions. The range of motion in the sagittal plane is similar across most thoracic and lumbar joints, with the exception of a lesser range at the transition region from thoracic-type to lumbar-type vertebrae. The upper thoracic column exhibits most of its range in dorsiflexion and the lower thoracic and lumbar in ventroflexion. Lateral flexion is limited to less than 5 degrees at all segments. The range in torsion is almost 180 degrees and occurs primarily in the midthoracic region, T4-T11. Contrary to the depiction in most atlases, the standing cat exhibits several curvatures, including a mild dorsiflexion in the lower lumbar segments, a marked ventroflexion in the lower thoracic and upper lumbar segments, and a profound dorsiflexion in the upper thoracic (above T9) and cervical segments. The curvatures are not significantly changed by altering stance distance but are affected by head posture. During stance, the top of the scapula lies well above the spines of the thoracic vertebrae, and the glenohumeral joint is just below the bodies of vertebrae T3-T5. Using a simple static model of the vertebral column in the sagittal plane, it was estimated that the bending moment due to gravity is bimodal with a dorsiflexion moment in the lower thoracic and lumbar region and a ventroflexion moment in the upper thoracic and cervical region. Given the bending moments and the position of the scapula during stance, it is proposed that two groups of scapular muscles provide the major antigravity support for the head and anterior trunk. Levator scapulae and serratus ventralis form the lateral group, inserting on the lateral processes of cervical vertebrae and on the ribs. The major and minor rhomboids form the medial group, inserting on the spinous tips of vertebrae from C4 to T4. It is also proposed that the hypaxial muscles, psoas major, minor, and quadratus lumborum could support the lumbar trunk during stance.

Animals↗
PubMed1986

Serratus anterior disruption: a complication of rheumatoid arthritis.

Pathology influencing the serratus anterior muscle contributes to classical medial winging of the scapula. Serratus anterior weakness or injury interferes with regular shoulder movement as this muscle stabilizes the medial border of the scapula against the thorax and rotates the scapula upward and laterally with arm elevation. Traumatic injury to the serratus anterior muscle without electrodiagnostic evidence of neurogenic involvement has only been reported once previously. We report an unusual case of disruption of the serratus anterior as a complication of rheumatoid arthritis. Involvement of the long thoracic nerve was ruled out by electromyography and nerve conduction studies. The injury occurred during routine activities of daily living and was complicated by a recurring subscapular hematoma. Contributing factors of shoulder joint contractures and coagulation abnormalities were associated with the course and treatment of rheumatoid arthritis. Initial treatment was by joint immobilization and reversal of coagulation abnormalities. Later treatment was directed toward joint protection and gradually increasing range of motion exercises.

Arthritis, Rheumatoid↗
PubMedDate not supplied

Stress and strain in the anterior band of the inferior glenohumeral ligament during a simulated clinical examination.

The objective of this research was to predict, with a finite-element model, the stress and strain fields in the anterior band of the inferior glenohumeral ligament (AB-IGHL) during application of an anterior load with the humerus abducted. The stress and strain in the AB-IGHL were determined during a simulated simple translation test of a single intact shoulder. A 6-degree-of-freedom magnetic tracking system was used to measure the kinematics of the humerus with respect to the scapula. A clinician applied an anterior load to the humerus until a manual maximum was achieved at 60 degrees of glenohumeral abduction and 0 degrees of flexion/extension and external rotation. For the computational analysis, the experimentally measured joint kinematics were used to prescribe the motion of the humerus with respect to the scapula, whereas the material properties of the AB-IGHL were based on published experimental data. The geometry of the AB-IGHL, humerus, and scapula was acquired by use of a volumetric computed tomography scan, which was used to define the reference configuration of the AB-IGHL. Strains reached 12% along the inferior edge and 15% near the scapular insertion site at the position of maximum anterior translation. During this motion, the AB-IGHL wrapped around the humerus and transferred load to the bone via contact. Predicted values for von Mises stress in the ligament reached 4.3 MPa at the point of contact with the humeral head and 6.4 MPa near the scapular insertion site. A comparison of these results to the literature suggests that the computational approach provided reasonable predictions of fiber strain in the AB-IGHL when specimen-specific geometry and kinematics with average material properties were used. The complex stress and strain distribution throughout the AB-IGHL suggests that the continuous nature of the glenohumeral capsule should be considered in biomechanical analyses. In the future, this combined experimental and computational approach will be used for subject-specific studies of capsular function and could provide quantitative data to help surgeons improve methods for the diagnosis and treatment of glenohumeral instability.

Biomechanical Phenomena↗
PubMed1978

Resorption of bone implants. The effect of in vivo incorporation of a diphosphonate and fluoride on resorption.

Weanling isogenously related rats were divided into one control group, one group given a fluoride supplement of 100 parts/10(6) of F- in the drinking water, and a third group given 0.5 mg per kg body weight of phosphorus as dichloromethylene diphosphanic acid (Cl2MDP). The rats were labeled with 1 muCi per g body weight of 3H proline and 40 muCi of 45Ca. Four weeks after labeling, the animals were sacrificed and one scapula was implanted subcutaneously in the back of an isogenously related rat of the same age. The other scapula was stored in a freezer pending analysis. After another 4 weeks the implants were recovered and the radioactivity of each isotope was compared with that of the initially stored scapulae. A 30-40% loss of activity was found, reflecting a considerable loss of bone. However, this loss was significantly lower (P less than 0.01) when Cl2MDP was given to the donor animals, whereas fluoride treatment did not affect the resorption.

Animals↗
PubMedDate not supplied

Three-dimensional computed tomographic volume rendering techniques in endoscopic thoracoplasty.

BACKGROUND CONTEXT: Thoracoplasty is occasionally necessary to achieve an acceptable cosmetic result in the presence of a rib hump, especially in previously fused young adults with scoliosis. This usually requires the resection of four to five rib segments, and the morbidity associated with open posterior resection or of open anterior resection by means of thoracotomy is often considerable, apart from leaving an unsightly scar. We thought the use of an endoscopic internal rib resection technique would achieve the desired result with less morbidity. Our experience with using the technique of three-dimensional (3-D) computed tomographic (CT) volume rendering to plan our portals and releases for endoscopic scoliosis correction led us to believe the same techniques could be adapted to plan and endoscopically carry out the thoracoplasty. PURPOSE: To define the utility of 3-D CT volume rendering of the spine and thorax in the preoperative planning of endoscopic rib resection. STUDY DESIGN: A prospective evaluation of the utility of 3-D CT volume rendering for preoperative planning in patients with scoliosis undergoing endoscopic thoracoplasty for correction of rib humps. PATIENT SAMPLE: Four consecutive patients with previously fused scoliotic spines and pronounced right-sided rib humps requiring operative correction were selected. OUTCOME MEASURES: Outcome was assessed at a minimum follow-up of 6 months by clinical examination, patient satisfaction with the clinical result, and repeat helical CT scanning with 3-D reconstruction. METHODS: Four patients with previously fused scoliotic spines and pronounced rib humps underwent helical CT scanning with 3-D volume rendering, prior to endoscopic corrective surgery. All four patients had right-sided rib humps requiring corrective rib resection for cosmetic reasons. Using the technique of 3-D volume rendering, a vector plane was created to mirror the left scapula, and its intersections on the right chest wall were noted. The ribs to be resected were marked, and the length of rib resection was measured from the vector plane's intersection points with the ribs. In this way an estimate of the resection required to achieve the desired final position of the right elevated scapula could be determined. Entry portals were also estimated with vector lines to achieve optimal access to each rib. During surgery, the portal sites were assessed for access to the selected ribs. Also, the extent of rib resections was compared with the estimates. The final clinical outcome was assessed by clinical examination, patient satisfaction with the cosmetic result, and repeat helical CT scanning with 3-D reconstruction. RESULTS: The male to female ratio was 1:3, and the average age was 21 years. Our average estimated blood loss was 307 ml and average hospital stay was 4.75 days. The estimated portal sites were accurate and did provide for direct access to each selected rib involved in the deformity. We were able to resect the ribs at the points suggested by 3-D CT volume rendering, with the lengths of our resected segments matching our preoperative estimates. In all cases the elevated right scapula did descend into the rib resection bed, thus balancing the shoulder heights. An excellent cosmetic result was achieved in all cases as evaluated by clinical examination, patient's perception, and repeat helical CT scanning. CONCLUSION: The technique of 3-D CT volume rendering with vector plane estimates provides a reliable estimate of the rib resection required to achieve a cosmetically acceptable correction of the rib hump through minimally invasive techniques.

Adolescent↗
PubMedDate not supplied

[The architecture of the subacromial space after full thickness supraspinatus tears].

AIM: The etiology of rotator cuff tears is multifactorial. An important factor is the damage of the rotator cuff by narrowing of the subacromial space. The purpose of this investigation was to estimate the influence of various metrical parameters on the size of the subacromial space. METHOD: We investigated 161 human macerated scapulae, 36 of them had a known tear of the supraspinatus tendon. All scapulae were photographed in two standard positions from the front and the lateral side. Defined distances and angles were measured using an image analyzing system followed by statistical analysis. RESULTS: Shoulders with a tear of the supraspinatus tendon showed a trend towards higher incidences of hooked acromions. Furthermore we found a significant higher incidence of elongated oval shaped glenoids in the group with supraspinatus tendon tear. In comparison to normal shoulders a significantly smaller distance from the top of the glenoid to the tip of the acromion and a greater distance from the top of the glenoid to the tip of the coracoid process was measured. In addition there was a significantly smaller coracoid angle and a smaller glenoid-spinal angle in this group. CONCLUSION: The width of the subacromial space depends on various parameters. Our data suggest that besides the acromion type the shape of the coracoid, the acromial angle, the spine-scapula angle and the cavitas-spine angle should be taken into account for diagnostic and therapeutic decisions.

Acromion↗
PubMed2002

Facial reconstruction using a combined flap of the subscapular axis simultaneously including separate medial and lateral scapular vascularized bone grafts.

With the better understanding of the blood supply to the scapula, combined flaps of the lateral scapula along with the latissimus dorsi and/or serratus anterior are well known. The medial border of the scapula, in this respect, has been underused. The authors present a case report in which a conjoined combined free flap consisting of four free tissue transfers based on the subscapular axis was used in simultaneous reconstruction of a gunshot wound to the face. This included a medial scapular osteofasciocutaneous flap for the mandible, a lateral scapular osseous flap for the anterior maxilla, a serratus anterior muscle flap for the cheek, and a separate latissimus dorsi musculocutaneous flap for the forehead. This flap was successful and provides another alternative to the resolution of complex problems needing multiple areas of both soft-tissue coverage and vascularized bone graft.

Bone Transplantation↗
PubMed2000

Successful restoration of the trapezius muscle using pedicle latissimus dorsi. A case report.

Reconstruction of the trapezius muscle using a pedicle latissimus dorsi flap was performed in a 27-year-old man with a large synovial sarcoma in his shoulder girdle. Size and location of the tumor required combined resection of surrounding muscles, including the trapezius, levator scapulae, and rhomboid major and minor. Thus, an extensive defect of the suspending muscles of the scapula was created after accomplishing an adequate resection of the tumor. The flap was performed to restore the trapezius functionally because there were no adjacent muscles available. The transferred muscle compensated for loss of the trapezius, thereby recovering excellent shoulder function. Although an opportunity of its application is thought to occur infrequently, the pedicle latissimus dorsi can activate scapular motion successfully in the absence of the levator scapulae. The technique may be extended to salvage failed conventional reconstruction after spinal accessory nerve palsy.

Accessory Nerve↗
PubMed1998

Exercise-induced pulmonary haemorrhage (EIPH) in horses results from locomotory impact induced trauma--a novel, unifying concept.

Exercise-induced pulmonary haemorrhage (EIPH) in horses, although of major welfare and economic importance worldwide, is of uncertain cause. It is accepted that the dorsocaudal region of the lung is particularly prone to the condition, but present theories of causation cannot satisfactorily explain the mechanism or pattern of occurrence. We propose that EIPH results from locomotory impact induced trauma; the mechanism being similar to that producing lung tissue damage following thoracic impact injury. In impact injury, the localised impulsive load on the chest wall is transmitted by pressure waves through the lung at a slower speed than in the chest wall. The waves are subsequently reflected from the distal chest wall and other structures, producing a complex pattern of wave motion; waves travelling from regions of large cross-section to narrower ones are amplified in magnitude, consequently these regions can experience very high local stresses. Compression/dilation and shear waves are produced within the parenchyma and the latter particularly have been implicated as the cause of parenchymal damage and rupture with oedema and haemorrhage. This form of soft tissue damage has been shown to occur at remarkably low loads with an impact velocity greater than about 11 m/s and pressure exceeding approximately 14 kPa. In the horse, the lung is subjected to comparable levels of locomotory derived impulsive force during moderate to high speed exercise and this is the basis of the mechanism causing EIPH. During locomotion, the force following ground-strike of the front legs is transmitted, with some attenuation, through the forelimbs to the scapulae. The anatomical arrangement of the scapula, coupled with the direction of the force at the shoulder (scapulo humeral joint) produces an impulsive force on the rib cage, approximately just below mid height of the frontal aspect of the chest approximately over the fourth rib. As a result, pressure waves are transmitted through the lung parenchyma towards the dorsal and caudal regions; these waves are subsequently reflected at the distal chest wall, spine and diaphragm causing a complex pattern of wave interaction. The observed locations of EIPH are at the sites where wave intensity is expected to be greatest due to changes in cross section and reflection. Based on available information, it is estimated that impulsive forces of more than 100 kPa, lasting approximately 10 ms, would be applied to the chest wall by each scapula in a 500 kg horse when galloping; this level of force would be sufficient to cause oedema and haemorrhage as observed in impact induced injury.

Animals↗
PubMed1991

Clinical significance of the V-shaped space in the subluxed shoulder of hemiplegics.

Recently, it has been proposed that shoulder subluxation in hemiplegia is accompanied by 1) the appearance of a V-shaped articular configuration occurring between the humeral head and glenoid fossa and 2) the presence of chronic pain. The main purpose of this study was to investigate the validity of these statements. We evaluated 40 hemiplegic subjects over 3 months. Radiographs of the affected and nonaffected shoulders were taken at both a frontal plane (0 degree) and a 45 degree incidence. From these patients, subluxed (n = 19) and nonsubluxed (n = 21) groups were formed. Pain was evaluated using the Present Pain Intensity index of the McGill Pain Questionnaire. On these x-ray films, measurements were taken of the V-shaped space, abduction of the arm, and rotation of the scapula. The statistical analysis (analysis of variance for repeated measures) contrasted the results obtained from the nonaffected side with those from the affected side over the 3 months studied. At the 45 degree angle, which better exposes the articular configuration of the shoulder, the difference in the V angle between the affected and nonaffected shoulders was significant for the subluxed group (p less than 0.01), indicating that such a V-shaped space can be identified. The measures taken also indicate that a downward subluxation of the humeral head occurs relative to the scapula without any systematic abduction of the humerus or downward rotation of the scapula. None of the results obtained from the frontal plane x-ray films was significant. Finally, no significant relation was found between subluxation and shoulder pain.

Adult↗
PubMed2004

Variations in muscle activation levels during traditional latissimus dorsi weight training exercises: An experimental study.

BACKGROUND: Exercise beliefs abound regarding variations in strength training techniques on muscle activation levels yet little research has validated these ideas. The purpose of the study is to determine muscle activation level, expressed as a percent of a normalization contraction, of the latissimus dorsi, biceps brachii and middle trapezius/rhomboids muscle groups during a series of different exercise tasks. METHODS: The average muscle activity during four tasks; wide grip pulldown, reverse grip pull down [RGP], seated row with retracted scapula, and seated rows with non-retracted scapulae was quantified during two 10 second isometric portions of the four exercises. A repeated measures ANOVA with post-hoc Tukey test was used to determine the influence of exercise type on muscle activity for each muscle. RESULTS & DISCUSSION: No exercise type influenced biceps brachii activity. The highest latissimus dorsi to biceps ratio of activation occurred during the wide grip pulldown and the seated row. Highest levels of myoelectric activity in the middle trapezius/rhomboid muscle group occurred during the seated row. Actively retracting the scapula did not influence middle trapezius/rhomboid activity. CONCLUSION: Variations in latissimus dorsi exercises are capable of producing small changes in the myoelectric activity of the primary movers.

Journal Article↗
PubMed2006

Surgical correction of unsuccessful derotational humeral osteotomy in obstetric brachial plexus palsy: evidence of the significance of scapular deformity in the pathophysiology of the medial rotation contracture.

BACKGROUND: The current method of treatment for persistent internal rotation due to the medial rotation contracture in patients with obstetric brachial plexus injury is humeral derotational osteotomy. While this procedure places the arm in a more functional position, it does not attend to the abnormal glenohumeral joint. Poor positioning of the humeral head secondary to elevation and rotation of the scapula and elongated acromion impingement causes functional limitations which are not addressed by derotation of the humerus. Progressive dislocation, caused by the abnormal positioning and shape of the scapula and clavicle, needs to be treated more directly. METHODS: Four patients with Scapular Hypoplasia, Elevation And Rotation (SHEAR) deformity who had undergone unsuccessful humeral osteotomies to treat internal rotation underwent acromion and clavicular osteotomy, ostectomy of the superomedial border of the scapula and posterior capsulorrhaphy in order to relieve the torsion developed in the acromio-clavicular triangle by persistent asymmetric muscle action and medial rotation contracture. RESULTS: Clinical examination shows significant improvement in the functional movement possible for these four children as assessed by the modified Mallet scoring, definitely improving on what was achieved by humeral osteotomy. CONCLUSION: These results reveal the importance of recognizing the presence of scapular hypoplasia, elevation and rotation deformity before deciding on a treatment plan. The Triangle Tilt procedure aims to relieve the forces acting on the shoulder joint and improve the situation of the humeral head in the glenoid. Improvement in glenohumeral positioning should allow for better functional movements of the shoulder, which was seen in all four patients. These dramatic improvements were only possible once the glenohumeral deformity was directly addressed surgically.

Journal Article↗
PubMed2003

Repetitive, negligible force reaching in rats induces pathological overloading of upper extremity bones.

UNLABELLED: Work-related repetitive motion disorders are costly. Immunohistochemical changes in bones resulting from repetitive reaching and grasping in 17 rats were examined. After 3-6 weeks, numbers of ED1+ macrophages and osteoclasts increased at periosteal surfaces of sites of muscle and interosseous membrane attachment and metaphyses of reach and nonreach forelimbs. These findings indicate pathological overloading leading to inflammation and subsequent bone resorption. INTRODUCTION: Sixty-five percent of all occupational illnesses in U.S. private industry are attributed to musculoskeletal disorders arising from the performance of repeated motion, yet the precise mechanisms of tissue pathophysiology have yet to be determined for work-related musculoskeletal disorders. This study investigates changes in upper extremity bone tissues resulting from performance of a voluntary highly repetitive, negligible force reaching and grasping task in rats. MATERIALS AND METHODS: Seventeen rats reached an average of 8.3 times/minute for 45-mg food pellets for 2 h/day, 3 days/week for up to 12 weeks. Seven rats served as normal or trained controls. Radius, ulna, humerus, and scapula were collected bilaterally as follows: radius and ulna at 0, 3, 4, 5, 6, and 12 weeks and humerus and scapula at 0, 4, and 6 weeks. Bones were examined for ED1-immunoreactive mononuclear cells and osteoclasts. Double-labeling immunohistochemistry was performed for ED1 (monocyte/macrophage lineage cell marker) and TRACP (osteoclast marker) to confirm that ED1+ multinucleated cells were osteoclasts. Differences in the number of ED1+ cells over time were analyzed by ANOVA. RESULTS: Between 3 and 6 weeks of task performance, the number of ED1+ mononuclear cells and osteoclasts increased significantly at the periosteal surfaces of the distal radius and ulna of the reach and nonreach limbs compared with control rats. These cells also increased at periosteal surfaces of humerus and scapula of both forelimbs by 4-6 weeks. These cellular increases were greatest at muscle attachments and metaphyseal regions, but they were also present at some interosseous membrane attachments. The number of ED1+ cells decreased to control levels in radius and ulna by 12 weeks. CONCLUSIONS: Increases in ED1+ mononuclear cells and osteoclasts indicate that highly repetitive, negligible force reaching causes pathological overloading of bone leading to inflammation and osteolysis of periosteal bone tissues.

Animals↗
PubMed1998

Contracture of the deltoid muscle. Results of distal release.

We prospectively studied the results of distal release, performed between February 1989 and December 1994 for the treatment of a contracture of the deltoid muscle, in forty patients (forty-nine shoulders). Forty-seven contractures (in thirty-eight patients) developed after multiple intramuscular injections of various medications. The two remaining contractures (in two patients) were congenital. The average age at the onset of the symptoms was thirty-two years (range, birth to fifty-eight years). The primary symptoms included pain around the neck and the shoulder girdle, dimpling of the skin, a palpable fibrous band, winging of the scapula, difficulty in combing the hair or reaching the contralateral side of the body for grooming, and inability to bring the arm adjacent to the body. The average age at the time of the operation was thirty-nine years (range, fifteen to sixty-three years). The average duration of follow-up was three years and eleven months (range, two years to six years and six months). After the distal release of the contracture, but on the same day, the patients started a physical-therapy program. Postoperatively, the pain, dimpling of the skin, palpable fibrous band, and winging of the scapula resolved in forty-eight shoulders (thirty-nine patients). Six patients (six shoulders) no longer had difficulty in combing the hair or adducting the shoulder. There were no infections or neuromuscular complications. Forty-seven (96 per cent) of the forty-nine shoulders (thirty-eight of the forty patients) had a good clinical result, and two shoulders (two patients) had a poor result. Anterosuperior subluxation of the humeral head, noted on preoperative radiographs of twenty-three shoulders (eighteen patients), was not present postoperatively. Drooping of the acromion, seen in six patients (six shoulders) in whom the contracture had developed before they were sixteen years old, improved postoperatively in five shoulders (five patients). Rotation of the scapula, seen in five shoulders (five patients), resolved after release of the contracture in all five. There were no clinical or radiographic signs of osteoarthrosis due to long-term anterior translation of the shoulder joint in the four patients (six shoulders) who had had the contracture for at least twenty years (average, twenty-three years; maximum, twenty-seven years).

Adolescent↗
PubMed1995

A modified internal rotation stretching technique for overhand and throwing athletes.

Strength, stretching, and rehabilitation methods for the shoulder have been previously described and have been universally applied; nevertheless, many throwing athletes continue to develop overuse injuries. The pitching process tends to increase external rotation and limit internal rotation of the shoulder joint. Our technique involves a modified stretching method of the posterior shoulder musculature. The athlete lies prone with the elbow flexed 90 degrees. With the shoulder abducted 90 degrees, in neutral flexion/extension, and 90 degrees or more of internal rotation, the scapula protrudes posteriorly. By depressing the inferior angle of the scapula toward the thoracic wall, the infraspinatus muscle and posterior joint capsule are effectively isolated and stretched. Manual stabilization of the scapula onto the chest wall transfers the internal rotation movements to the glenohumeral joint, as opposed to sharing the movement with the scapulothoracic articulation. This method improves the efficacy of the internal rotation stretching exercise for the glenohumeral joint. Such an addition to traditional stretching methods may increase the efficiency of the least effective component. We conclude that this modification to traditional programs should be an integral part of the training and rehabilitation program of any athlete requiring near maximal performance of the shoulder.

Athletic Injuries↗
PubMed2002

Determining the resting position of the glenohumeral joint: a cadaver study.

STUDY DESIGN: Single-session repeated-measures design. OBJECTIVE: To define the resting position of the glenohumeral joint by investigating the magnitude of the anterior and posterior displacements of the humeral head and medial and lateral rotation ranges of motion (ROMs) of the glenohumeral joint at different abduction angles in cadaver specimens. BACKGROUND AND PURPOSE: The resting position of a joint is the position in the joint's ROM at which the joint capsule has its greatest laxity. It is frequently chosen as the position for assessing and treating joints with dysfunction. However, no study has been conducted to determine the resting position of the glenohumeral joint. METHODS: Seven freshly frozen cadaver shoulder specimens (age at time of death [mean +/- SD] was 66.9 +/- 2.5 years) were studied. Specimens were mounted on a system that uses computer-controlled hydraulics and motors to induce and monitor translation and rotation movements of the glenohumeral joint. The magnitudes of total displacement (DTotal) of the head of the humerus and total ROM (RTotal) of the glenohumeral joint were measured in the plane of the scapula at 0 degrees (neutral), 30 degrees, 40 degrees, 50 degrees, 60 degrees, and the end range of glenohumeral joint abduction. The resting position was determined as the midpoint of the shared range of the 95% to 99.9% confidence intervals of the predicted abduction position where the peaks of displacement and rotation occurred. RESULTS: The DTotal measurements (mean +/- SD) at 0 degrees, 30 degrees, 40 degrees, 50 degrees, 60 degrees, and the end range of glenohumeral joint abduction were 30.53 +/- 9.35, 44.87 +/- 7.34, 45.35 +/- 8.53, 43.99 +/- 10.02, 39.63 +/- 9.85, and 23.80 +/- 10.42 mm, respectively. The RTotal measurements (mean +/- SD) for the same positions were 67.15 degrees +/- 15.87 degrees, 95.64 degrees +/- 24.26 degrees, 98.88 degrees +/- 29.56 degrees, 97.08 degrees +/- 30.17 degrees, 90.91 degrees +/- 28.73 degrees, and 63.48 degrees +/- 25.93 degrees, respectively. The resting position was located at 39.33 degrees +/- 4.37 degrees of glenohumeral abduction (45.13% +/- 7.58% of the available abduction ROM). The resting position (Y) varied linearly with the maximum available abduction ROM (X) (Y = 0.607X - 13.120, R2 = 0.679, F = 10.61, P = 0.023). There was a main effect of joint position on both displacement (P<0.001) and rotation ROM (P<0.001). CONCLUSION: In the plane of the scapula, the resting position of the glenohumeral joint (angle measured between the scapula and humerus) occurred at 39 degrees of abduction (45% of the maximum available abduction ROM) and varied linearly with the amount of available abduction ROM. This finding suggests that in patients with glenohumeral joint hypomobility the resting position is located closer to neutral and that evaluation and treatment should be initiated accordingly at a smaller angle of abduction than the traditional resting position. Our data were derived from cadaver specimens, therefore, caution should be taken when generalizing the results of the present study to a patient population.

Aged↗