Scapula rotation

Tilt Depends on joint Depends on joint Term used to describe certain movements of the scapula and pelvis. In the scapula, an anterior tilt occurs when the coracoid process moves in an anterior and downward direction while the inferior angle moves in a posterior and upward direction. A posterior tilt of the scapula is the opposite of an anterior tilt. In the pelvis, an anterior tilt is rotation of the anterior superior spines (ASISs) of the pelvis in an anterior and downward direction a posterior tilt is movement of the ASISs in a posterior and upward direction. A lateral tilt of the pelvis occurs when the pelvis is not in level from side to side, but one ASIS is higher than the other one. 

A combination of glenohumeral flexion and shoulder abduction is the primary body-control motion used to affect terminal device opening and closing or elbow flexion and extension. Typically, a total excursion of 10 cm (4 in) and upward of 222 N (50 Ibf) of force are possible using these motions. Elbow lock control is affected by a complex shoulder motion which involves downward rotation of the scapula combined with simultaneous abduction and slight extension of the shoulder... 

The easiest way to achieve this position is to have the child standing facing a cassette with the affected arm held across the body holding the unaffected shoulder. The child is then rotated until the scapula lies perpendicular to the cassette. 

Place a palm flat on the posterior surface of each scapula, with your fingers resting on the superior scapular border. Are the scapulae rotated Are they level ... 

Repeat the same examination with the scapulae and rib cage. Are they rotated ... 

Flexion or extension is added, depending on the diagnosis of the dysfunction. If the somatic dysfunction is a flexion dysfunction, the physician uses the hand on the patient s shoulder and scapula to first introduce flexion of the spine to that level. If the direction of the somatic dysfunction is extension, then the physician initially pushes the patient s shoulder posteriorly. By pushing the patient s shoulder posteriorly, the physician rotates the patient s... 

A short leg has numerous effects on the body. Usually, the sacral base lilts toward the side of the short leg. The iliac crest is generally low on the short leg side. Occasionally, the innominate on the shorter side will rotate forward or the opposite side posteriorly as a means of compensating for the leg length discrepancy. The lumbar spine develops a convexity toward the side of the short leg, and once the problem has existed for sufficient time, a compensatory curve will develop in the thoracic spine. The shoulder will be low on one side, depending on whether a secondary thoracic curve is present the scapula will be low on the same side as the shoulder. The cervical angle will be more acute as the head tilts toward the midline to keep the eyes level. 

The scapulothoracic joint movements are related to scapular motions. The motions are medial and lateral movements of the scapula on the thorax (abduction-adduction), elevation of the scapula, and upward and downward rotation of the scapula (tilt), all relative to the glenoid fossa. 

In the second phase (90 to 150 degrees), upward rotation of the scapula causes the glenoid fossa to tilt and face upwards as the humerus locks on the glenoid fossa. The trapezius and serratus anterior primarily contribute. The movement is restricted to some extent by the pectoralis major and latissimus dorsi but is facilitated by concomitant rotations of the sternoclavicular and acromioclavicular joints. 

The humerus impinges on the acromial arch at 90 degrees. To prevent impingement and permit abduction to 180 degrees, the scapula must rotate. 

The fibers of the deltoid, attached from the scapula to the humerus, contract to abduct the arm to 90 degrees, at which point they are maximally contracted. As the fossa rotates upward, it maintains the deltoid in position for maximal contraction, allowing the humerus to continue to 180 degrees. 

The scapulohumeral rhythm is a free-flowing and synchronous movement of the scapula and humerus. During abduction, the scapula rotates as the humerus elevates. For every 15 degrees of abduction, humeral elevation accounts for 10 degrees and scapular rotation accounts for 5 degrees. Dysfunction of humeral elevation or of scapular rotation can disturb this rhythm and interfere with shoulder function. Dysfunction of clavicular motion can also interfere with this rhythm. 

The clavicle moves during most shoulder activity. Dysfunctions in clavicular motion can interfere with normal shoulder movement. The combined axial rotation of the sternoclavicular joint (30 degrees) and the acromioclavicular joint (30 degrees) allows the normal 60 degrees of rotation of the scapula on full abduction of the shoulder. 

To increase internal rotation The patient s hand, with the elbow flexed, is placed behind his lower ribs. The physician s upper hand locks the scapula her lower hand gently draws the patient s elbow forward and down (Fig. 88-6). The patient s elbow is released and the maneuver is repeated. Care must be used in the motion because it may be the most painful to the patient. An external rotation force may also be used in this position. 

First, the kinematic equation is constructed by obtaining the direction of cosines tables. Direction of cosines is obtained by using Euler Rotational Series which is a series of three rotations used to define uniquely the orientation of rigid body in 3-dimensional space. Table 1 summarize the direction of cosines for reference frame of scapula (N) acting on reference frame of humerus (A). 

In addition to the subacromial gliding plane, the scapulothoracic plane facilitates movement of the scapula relative to the chest wall and rotation of the scapula during abduction and adduction of the arm. 

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