Lippert Ch. 10

inflammation and fibrosis of the shoulder joint capsule, which leads to pain and loss of shoulder range of motion. It is also known as frozen shoulder.

Adhesive capsulitis

usually involves the long head of the biceps proximally as it crosses the humeral head, changes direction, and descends into the bicipital groove. A rupture of the biceps long head tendon commonly occurs during repetitive or forceful overhead positions.

Bicipital tendonitis

The muscles that span the shoulder joint are as follows:

Deltoid Pectoralis major Latissimus dorsi Teres major Supraspinatus Infraspinatus Teres minor Subscapularis Coracobrachialis Biceps brachii Triceps brachii, long head

commonly seen in individuals who have hemiplegia, usually from a cerebrovascular accident (stroke). Paralysis of the shoulder muscles leaves them no longer able to hold the head of the humerus in the glenoid fossa. This paralysis, combined with the pull of gravity and the weight of the arm, over time causes this partial dislocation.

Glenohumeral subluxation

overuse condition that involves compression between the acromial arch, the humeral head, and soft tissue structures. These soft tissues include the coracoacromial ligament, rotator cuff muscles, long head of the biceps, and subacromial bursa. A type of impingement known as swimmer's shoulder is common with swimmers specializing in freestyle, butterfly, and backstroke.

Impingement syndrome

injury caused by a direct blow or a twisting force

Midhumeral fracture

_______________________ of the humerus may be caused by benign tumors or metastatic carcinoma from primary sites such as the lung, breast, kidney, and prostate

Pathological fractures

If you observe the distal attachments of the supraspinatus, infraspinatus, and teres minor muscles on the greater tubercle of the humerus, you will notice that they are essentially in a line (Fig. 10-17). For this reason, they are collectively referred to as the __________, taking the first letter from each muscle. These three muscles plus the subscapularis are referred to as the rotator cuff, or _______________

SIT muscles, SITS muscles

concept that describes the action of the shoulder girdle and the deltoid muscles, especially the middle deltoid muscle, during shoulder abduction The deltoid muscle is at optimal length when the arm is at the side. If the humerus is the only bone that moved during abduction, the middle deltoid muscle would quickly shorten beyond optimal length and run out of contractile power as it approached 90 degrees. However, the middle deltoid muscle is effective throughout the entire range. Remember that for every 2 degrees the shoulder joint abducts, the shoulder girdle upwardly rotates 1 degree (scapulohumeral rhythm; see Chapter 9). With this upward rotation of the scapula, the origin of the deltoid muscle (the acromion process, the lateral end of the clavicle, and the scapular spine) moves away from the insertion on the humerus. This motion lengthens the muscle, restoring its contractile potential (optimal length-tension relationship), and allows it to continue to effectively contract throughout its entire range.

The "inchworm effect"

With the arm hanging at the side, the superior portion of the capsule is taut, and the inferior part is slack. When the shoulder is abducted, the opposite occurs:

The inferior portion is taut, and the superior part is slack

several bursae in the shoulder joint area

The subdeltoid bursa is large and located between the deltoid muscle and the joint capsule. The subacromial bursa lies below the acromion and coracoacromial ligament, between them and the joint capsule, and it is frequently continuous with the subdeltoid bursa.

Arthrokinematic motions during shoulder flexion and extension.

When the shoulder joint flexes, the humeral head glides posteriorly. During extension, the humeral head glides anteriorly.

One of the most common joint dislocations involves the shoulder, and most of those are

anterior shoulder dislocations A forced shoulder abduction and lateral rotation tends to be the dislocating motion causing the humeral head to slide anteriorly out of the glenoid fossa

Chronic inflammation of the supraspinatus tendon can lead to an accumulation of mineral deposits and can result in

calcific tendonitis, which may be asymptomatic or quite painful.

It strengthens the upper part of the joint capsule.

coracohumeral ligament

reinforce the anterior portion of the capsule

glenohumeral ligaments

Its function is to deepen the articular cavity

glenoid labrum

injury caused by a fall on the outstretched hand. It is common in the elderly and usually results in an impacted fracture

humeral neck fracture

With the arm hanging at the side, the superior portion of the shoulder joint capsule...

is taut, and the inferior part is slack

damage to the glenoid labrum. It can have a degenerative or traumatic etiology and results in pain and limited motion in the shoulder joint.

labral tear

Spiral fractures in this region increase the risk of a

radial nerve injury, as the nerve passes next to the bone in the spiral groove

Another term frequently seen in the literature, especially regarding therapeutic exercise for shoulder conditions, is ___________. This motion is similar to flexion or abduction but occurs in the scapular plane as opposed to the sagittal or frontal plane (see Fig. 9-3). The scapular plane is approximately 30 degrees forward of the frontal plane. It is not quite midway between flexion and abduction. With scaption of the shoulder, 180 degrees of up and down motion is possible. Most common functional activities occur in the scapular plane.

scaption

Irritation as it slides in the groove can lead to

subluxing of the biceps tendon (long head). Overloading the muscle in an abducted and laterally rotated position tends to be the force subluxing the tendon out of the bicipital groove.

rotator cuff and fuction

tendinous band formed by the blending together of the tendinous insertions of the subscapularis, supraspinatus, infraspinatus, and teres minor muscles These muscles help to keep the head of the humerus against the glenoid fossa during joint motion. This rotating motion is what inspired the term rotator cuff, not the muscular action of medial or lateral rotation.

superficial fibrous sheet that attaches to the spinous processes of the lower thoracic and lumbar vertebrae, the supraspinal ligament, and the posterior part of the iliac crest, covering the sacrospinalis muscle. It provides a very broad attachment for the latissimus dorsi muscle.

thoracolumbar fascia (lumbar aponeurosis)

distal tendinous insertion of the supraspinatus, infraspinatus, teres minor, and subscapularis on the greater/lesser tubercle area of the humerus. Tears can be the result of acute trauma or gradual degeneration.

torn rotator cuff

shoulder motion

(1) flexion, extension, and hyperextension; (2) abduction and adduction; (3) medial and lateral rotation; and (4) horizontal abduction and adduction. Flexion, extension, and hyperextension occur in the sagittal plane around the frontal axis. Flexion is from 0 to 180 degrees, and extension is the return to anatomical position. Approximately 45 degrees of hyperextension is possible from the anatomical position. Abduction and adduction occur in the frontal plane around the sagittal axis, with 180 degrees of motion possible. Medial and lateral rotation occur in the transverse plane around the vertical axis. Sometimes the terms internal and external are used in place of medial and lateral, respectively. From a neutral position, it is possible to move 90 degrees in each direction. Horizontal abduction and horizontal adduction also occur in the transverse plane around the vertical axis. From an arbitrary starting position for these motions of 90 degrees of shoulder abduction, there would be approximately 30 degrees of horizontal abduction (backward motion) and approximately 120 degrees of horizontal adduction (forward motion).