Scapulohumeral Rhythm: Difference between revisions

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There isn’t really a differential diagnosis for scapulohumeral rhythm disorders. But there are multiple causes for [[scapular dyskinesia]] and scapulohumeral rhythm disorders. <ref name="28">Kibler WB et al., Scapular dyskinesis and its relation to shoulder injury, J Am Acad Orthop Surg, 2012 Jun;20(6):364-72. Level of Evidence: 3A. </ref> Causative factors can be grouped into:
There isn’t really a differential diagnosis for scapulohumeral rhythm disorders. But there are multiple causes for [[scapular dyskinesia]] and scapulohumeral rhythm disorders. <ref name="28">Kibler WB et al., Scapular dyskinesis and its relation to shoulder injury, J Am Acad Orthop Surg, 2012 Jun;20(6):364-72. Level of Evidence: 3A. </ref> Causative factors can be grouped into:


* Bony causes include [[thoracic kyphosis]] or [[clavicle fracture]].
* Bony causes include thoracic kyphosis or [[clavicula fracture]].


* Joint causes include high grade AC instability, AC arthrosis and instability and GH joint internal derangement.
* Joint causes include high grade AC instability, AC arthrosis and instability and GH joint internal derangement.


* Neurological causes include [[cervical radiculopathy]], long thoracic or spinal accessorynerve palsy.
* Neurological causes include [[Cervical Radiculopathy]], long thoracic or spinal accessorynerve palsy.


* Inflexibility causes, for example: inflexibility and stiffness of the pectoralis minor and biceps short head can create anterior tilt and protraction due to their pull on the coracoid. <ref name="38">Borstad JD et al., The effect of long versus short pectoralis minor resting length on scapular kinematics in healthy individuals, J Orthop Sports Phys Ther 2005;35:227–38. Level of Evidence: 3B. </ref>  Soft tissue posterior shoulder inflexibility can lead to GH internal rotation deficit (GIRD), which creates a ‘wind-up’ of the scapula on the thorax with reduced humeral internal rotation and horizontal abduction.
* Inflexibility causes, for example: inflexibility and stiffness of the pectoralis minor and biceps short head can create anterior tilt and protraction due to their pull on the coracoid. <ref name="38">Borstad JD et al., The effect of long versus short pectoralis minor resting length on scapular kinematics in healthy individuals, J Orthop Sports Phys Ther 2005;35:227–38. Level of Evidence: 3B. </ref>  Soft tissue posterior shoulder inflexibility can lead to GH internal rotation deficit (GIRD), which creates a ‘wind-up’ of the scapula on the thorax with reduced humeral internal rotation and horizontal abduction.
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* Muscular causes: Serratus anterior activation and strength is decreased in patients with impingement and shoulder pain, contributing to the loss of posterior tilt and upward rotation causing dyskinesis. <ref name="35">McQuade KJ et al., Effects of local muscle fatigue on three-dimensional scapulohumeral rhythm, Clin Biomech, 1995 Apr;10(3):144-148. Level of Evidence: 4. </ref> <ref name="39">Cools AM et al., Rehabilitation of scapular muscle balance, Am J Sports Med 2007;35:1744–51. Level of Evidence: 4. </ref>  In addition, the upper trapezius/lower trapezius force couple may be altered, with delayed onset of activation in the lower trapezius, which alters scapular upward rotation and posterior tilt. Altered scapular motion or position both decrease linear measures of the subacromial space <ref name="40">Seitz AL et al., Effects of scapular dyskinesis and scapular assistance test on subacromial space during static arm elevation. J Shoulder Elbow Surg 2012;21:631–40. Level of Evidence: 3B. </ref> <ref name="41">Atalar H et al., Restricted scapular mobility during arm abduction: implications for impingement syndrome. Acta Orthopaedica Belgica 2009;75:19–24. Level of Evidence: 3B. </ref>, increase impingement symptoms, decrease rotator cuff strength <ref name="42">Smith J et al., Effect of scapular protraction and retraction on isometric shoulder elevation strength. Arch Phys Med Rehabil 2002;83:367–70. Level of evidence: 3B. </ref>, increase strain on the anterior GH ligaments <ref name="43">Weiser WM et al., Effects of simulated scapular protraction on anterior glenohumeral stability. Am J Sports Med 1999;27:801–5. and increase the risk of internal impingement. Level of Evidence: 4. </ref>  
* Muscular causes: Serratus anterior activation and strength is decreased in patients with impingement and shoulder pain, contributing to the loss of posterior tilt and upward rotation causing dyskinesis. <ref name="35">McQuade KJ et al., Effects of local muscle fatigue on three-dimensional scapulohumeral rhythm, Clin Biomech, 1995 Apr;10(3):144-148. Level of Evidence: 4. </ref> <ref name="39">Cools AM et al., Rehabilitation of scapular muscle balance, Am J Sports Med 2007;35:1744–51. Level of Evidence: 4. </ref>  In addition, the upper trapezius/lower trapezius force couple may be altered, with delayed onset of activation in the lower trapezius, which alters scapular upward rotation and posterior tilt. Altered scapular motion or position both decrease linear measures of the subacromial space <ref name="40">Seitz AL et al., Effects of scapular dyskinesis and scapular assistance test on subacromial space during static arm elevation. J Shoulder Elbow Surg 2012;21:631–40. Level of Evidence: 3B. </ref> <ref name="41">Atalar H et al., Restricted scapular mobility during arm abduction: implications for impingement syndrome. Acta Orthopaedica Belgica 2009;75:19–24. Level of Evidence: 3B. </ref>, increase impingement symptoms, decrease rotator cuff strength <ref name="42">Smith J et al., Effect of scapular protraction and retraction on isometric shoulder elevation strength. Arch Phys Med Rehabil 2002;83:367–70. Level of evidence: 3B. </ref>, increase strain on the anterior GH ligaments <ref name="43">Weiser WM et al., Effects of simulated scapular protraction on anterior glenohumeral stability. Am J Sports Med 1999;27:801–5. and increase the risk of internal impingement. Level of Evidence: 4. </ref>  


Alterations in scapular position and control afforded by the scapula stabilizing muscles are believed to disrupt stability and function of the glenohumeral joint <ref name="1"/> <ref name="22">Itoi E. Scapular inclination and inferior stability of the shoulder. J Shoulder Elbow Surg 1992;1:131-139. Level of Evidence: 5. </ref> <ref name="23">Weiser WM, Lee TQ, McMaster WC, McMahon PJ. Effects of simulated scapular protraction on anterior glenohumeral stability. Am J Sports Med 1999; 27: 801-805. Level of Evidence: 5. </ref>, thereby contributing to shoulder impingement, rotator cuff pathology and shoulder instability. <ref name="24">Ludewig PM, Reynolds JF. The association of scapular kinematics and glenohumeral joint pathologies. J Orthop Sports Phys Ther 2009;39: 90-104. Level of Evidence: 5. </ref>  
Alterations in scapular position and control afforded by the scapula stabilizing muscles are believed to disrupt stability and function of the glenohumeral joint <ref name="1"/> <ref name="22">Itoi E. Scapular inclination and inferior stability of the shoulder. J Shoulder Elbow Surg 1992;1:131-139. Level of Evidence: 5. </ref> <ref name="23">Weiser WM, Lee TQ, McMaster WC, McMahon PJ. Effects of simulated scapular protraction on anterior glenohumeral stability. Am J Sports Med 1999; 27: 801-805. Level of Evidence: 5. </ref>, thereby contributing to shoulder impingement, rotator cuff pathology and shoulder instability. <ref name="24">Ludewig PM, Reynolds JF. The association of scapular kinematics and glenohumeral joint pathologies. J Orthop Sports Phys Ther 2009;39: 90-104. Level of Evidence: 5. </ref>
 


== References  ==
== References  ==

Revision as of 23:19, 27 February 2016

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Search Strategy[edit | edit source]

We searched on the websites of Web of Science and Pubmed using the terms: "Scapular Humeral Rhythm", "Scapula Dyskinesia", "Scapula Position", "Scapula Stabilization", "Shoulder Movements", "Codman" and "Glenohumeral Motion".

Definition / Description[edit | edit source]

Scapulohumeral rhythm (also referred to as glenohumeral rhythm) is the kinematic interaction between the scapula and the humerus, first published by Codman in the 1930s. Cite error: Invalid <ref> tag; name cannot be a simple integer. Use a descriptive title

This interaction is important for the optimal function of the shoulder. Cite error: Invalid <ref> tag; name cannot be a simple integer. Use a descriptive title When there is a change ment of the normal position of the scapula(describe) relative to the humerus, can this can cause a disfunction of the scapulohumeral rhythm. The change ment of the normal position is also called scapular dyskinesia. Various studies of the mechanism of the shoulder joint have attempted to describe the global motion capacity of the shoulder refer to that description, can you evaluate the shoulder to see if the function is correct? and explain the complex interactions between components involved in placing the hand in space.Cite error: Invalid <ref> tag; name cannot be a simple integer. Use a descriptive title Cite error: Invalid <ref> tag; name cannot be a simple integer. Use a descriptive title

Clinical Relevant Anatomy[edit | edit source]

Shoulder movements

The interplay of 4 articulations (Sternoclavicular joint, Acromioclavicular joint, scapulothoracic joint and glenohumeral joint) of the shoulder complex, results in an coordinated movement pattern of the arm elevation. The involved movements at each joint are continuous, although occurring at various rates and at different phases of arm elevation. The movement of the scapula can be described by rotations in relation to the thorax. The scapula moves around a dorso-ventral axis, resulting in a rotation in the frontal plane. In this movement the glenoid cavity is turned cranially (upward rotation) or caudally (downward rotation). In the sagittal plane, around a latero-lateral axis the scapula rotates posteriorly (posterior tilting) or anteriorly (anterior tilting). External and internal rotation occurs around a cephalo-caudal (longitudinal) axis. The external rotation brings the glenoid cavity more into the frontal plane, whereas the internal rotation turns the glenoid cavity more to the sagittal plane. Cite error: Invalid <ref> tag; name cannot be a simple integer. Use a descriptive title

When we perform flexion, the glenohumeral (GH) joint contributes 100°-120°. The scapula on the thorax contributes to elevation (flexion and abduction) of the humerus by upwardly rotating the glenoid fossa 50° to 60° from its resting position.Cite error: Invalid <ref> tag; name cannot be a simple integer. Use a descriptive title If the humerus were fixed to the fossa, this alone would result in up to 60° of elevation of the humerus. The humerus, of course, is not fixed but can move independently on the glenoid fossa.

Inman et al. reported an inconsistent amount and type of scapular motion in relation to GH-motion during the initial 60°. Cite error: Invalid <ref> tag; name cannot be a simple integer. Use a descriptive title In this early phase (0-60°), motion occurs primarily at the GH joint, although stressing the arm may increase the scapular contribution. Cite error: Invalid <ref> tag; name cannot be a simple integer. Use a descriptive title During abduction of the humerus in the plane of the scapula, an average of 43° of lateral rotation from the resting position has been reported, with peak lateral rotation generally occurring between 90° and 120° of humeral elevation. It must also be recognized, however, that elevation of the arm is often accompanied not only by elevation of the humerus but also by lateral rotation of the humerus in relation to the scapula. Cite error: Invalid <ref> tag; name cannot be a simple integer. Use a descriptive title

When we perform abduction, the GH-joint contributes 90-120°. The combination of scapular and humeral movement result in a maximum range of elevation of 150-180°. Cite error: Invalid <ref> tag; name cannot be a simple integer. Use a descriptive title Cite error: Invalid <ref> tag; name cannot be a simple integer. Use a descriptive title Also by abduction Inman et al. reported an inconsistent amount and type of scapular motion in relation to GH-motion this time during the initial 30°. Cite error: Invalid <ref> tag; name cannot be a simple integer. Use a descriptive title In this early phase, motion occurs primarily at the GH joint, although stressing the arm may increase the scapular contribution. Cite error: Invalid <ref> tag; name cannot be a simple integer. Use a descriptive title

Scapulohumeral Ratio

Scapulohumeral rhythm or ratio is significantly greater (less scapular motion and more humeral motion) in the sagittal plane than other planes. Consistent with the findings, the dominant side demonstrated significantly higher values for SH rhythm than the non-dominant side but only in the coronal and scapular planes but not in the sagittal plane. Cite error: Invalid <ref> tag; name cannot be a simple integer. Use a descriptive title By healthy male is a significant difference by hand dominance only in scapular upward rotation during scapular plane arm elevation.Cite error: Invalid <ref> tag; name cannot be a simple integer. Use a descriptive title

The scapulohumeral rhythm is therefore defined as the ratio of the glenohumeral movement to the scapulothoracic movement during arm elevation. This is most often calculated by dividing the total amount of shoulder elevation (humerothoracic) by the scapular upward rotation (scapulothoracic). Cite error: Invalid <ref> tag; name cannot be a simple integer. Use a descriptive title

In the literature Scapulohumeral rhythm is descibed like a ratio: humeral elevation:scapulothoracal rotation. The overall ratio of 2:1during arm elevation is commonly used. According to the 2-to-1 ratio frame-work, flexion or abduction of 90° in relation to the thorax would be accomplished through approximately 60° of GH and 30° of ST motion. In another study of Scapulohumeral rhythm between children and adults, the mean ratio for the scapular plane was 2.4:1 for adults, 1.3:1 for children. Cite error: Invalid <ref> tag; name cannot be a simple integer. Use a descriptive title

If we compare the scapulohumeral rhythm by children with adults, we see that children showed a higher scapulohumeral rhythm during lowering of the arm than adults. Cite error: Invalid <ref> tag; name cannot be a simple integer. Use a descriptive title Also during scapular plane rotation from 25° to 125°, children showed greater upward rotation than adults. Cite error: Invalid <ref> tag; name cannot be a simple integer. Use a descriptive title

Epidemiology / Etiology[edit | edit source]

It has been reported that scapular dyskinesis occurs in 68 - 100 % of patients with shoulder injuries (including glenohumeral instability, rotator cuff abnormalities, and labral tears. Cite error: Invalid <ref> tag; name cannot be a simple integer. Use a descriptive title Other studies showed that scapular upward rotation is significantly increased in patients with full-thickness rotator cuff tears compared with controls in both sagittal and scapular plane elevation. Also, an increased scapular component is generally thought to contribute to the scapulohumeral rhythm ratio in frozen or stiff shoulders. Cite error: Invalid <ref> tag; name cannot be a simple integer. Use a descriptive title

Given the role of the scapula in shoulder function, the ability to monitor the coordinated motion of the scapula and humerus (scapulohumeral rhythm) may have clinical implications when dealing with overhead athletes and patients with shoulder pathologies. Cite error: Invalid <ref> tag; name cannot be a simple integer. Use a descriptive title

Sports participation results in slight differences in side-to-side motion and in scapular resting position in overhead athletes. Cite error: Invalid <ref> tag; name cannot be a simple integer. Use a descriptive title Cite error: Invalid <ref> tag; name cannot be a simple integer. Use a descriptive title Overhead athletes have some asymmetry in scapular upward rotation and scapulohumeral rhythm ratio between dominant and non-dominant shoulder. It should not be considered automatically as a pathological sign but rather an adaptation to sports practice and extensive use of upper limb. Cite error: Invalid <ref> tag; name cannot be a simple integer. Use a descriptive title

People with higher BMI have scapula kinematic patterns different from people with lower BMI. They have increased scapula upward rotation during arm elevation. Cite error: Invalid <ref> tag; name cannot be a simple integer. Use a descriptive title

Characteristics / Clinical Presentation[edit | edit source]

Scapulohumeral rhythm is a common metric for assessing muscle function and shoulder joint motion.Cite error: Invalid <ref> tag; name cannot be a simple integer. Use a descriptive title There is a three-dimensional scapular kinematic pattern during normal arm elevation that include upward rotation, posterior tilting and varying internal/external rotation dependent on the plane and angle of elevation. Cite error: Invalid <ref> tag; name cannot be a simple integer. Use a descriptive title Cite error: Invalid <ref> tag; name cannot be a simple integer. Use a descriptive title When there is a changement of the normal position of the scapula related to the humerus, the scapulohumeral rhythm is disturbed.

Differential Diagnosis[edit | edit source]

There isn’t really a differential diagnosis for scapulohumeral rhythm disorders. But there are multiple causes for scapular dyskinesia and scapulohumeral rhythm disorders. Cite error: Invalid <ref> tag; name cannot be a simple integer. Use a descriptive title Causative factors can be grouped into:

  • Joint causes include high grade AC instability, AC arthrosis and instability and GH joint internal derangement.
  • Inflexibility causes, for example: inflexibility and stiffness of the pectoralis minor and biceps short head can create anterior tilt and protraction due to their pull on the coracoid. Cite error: Invalid <ref> tag; name cannot be a simple integer. Use a descriptive title Soft tissue posterior shoulder inflexibility can lead to GH internal rotation deficit (GIRD), which creates a ‘wind-up’ of the scapula on the thorax with reduced humeral internal rotation and horizontal abduction.
  • Muscular causes: Serratus anterior activation and strength is decreased in patients with impingement and shoulder pain, contributing to the loss of posterior tilt and upward rotation causing dyskinesis. Cite error: Invalid <ref> tag; name cannot be a simple integer. Use a descriptive title Cite error: Invalid <ref> tag; name cannot be a simple integer. Use a descriptive title In addition, the upper trapezius/lower trapezius force couple may be altered, with delayed onset of activation in the lower trapezius, which alters scapular upward rotation and posterior tilt. Altered scapular motion or position both decrease linear measures of the subacromial space Cite error: Invalid <ref> tag; name cannot be a simple integer. Use a descriptive title Cite error: Invalid <ref> tag; name cannot be a simple integer. Use a descriptive title, increase impingement symptoms, decrease rotator cuff strength Cite error: Invalid <ref> tag; name cannot be a simple integer. Use a descriptive title, increase strain on the anterior GH ligaments Cite error: Invalid <ref> tag; name cannot be a simple integer. Use a descriptive title

Alterations in scapular position and control afforded by the scapula stabilizing muscles are believed to disrupt stability and function of the glenohumeral joint Cite error: Invalid <ref> tag; name cannot be a simple integer. Use a descriptive title Cite error: Invalid <ref> tag; name cannot be a simple integer. Use a descriptive title Cite error: Invalid <ref> tag; name cannot be a simple integer. Use a descriptive title, thereby contributing to shoulder impingement, rotator cuff pathology and shoulder instability. Cite error: Invalid <ref> tag; name cannot be a simple integer. Use a descriptive title

References[edit | edit source]



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