1. © McGraw-Hill Higher Education. All rights reserved. 4-1 Chapter 4 The Shoulder Girdle Manual of Structural Kinesiology R.T. Floyd, EdD, ATC, CSCS

2. © McGraw-Hill Higher Education. All rights reserved. 4-2 Bones Scapula & clavicleScapula & clavicle –Move as a unit –Clavicle’s articulation with sternum is only bony link to axial skeleton

3. © McGraw-Hill Higher Education. All rights reserved. 4-3 Bones Key bony landmarksKey bony landmarks –Manubrium –Clavicle –Coracoid process –Acromion process –Glenoid fossa –Lateral border –Inferior angle –Medial border

4. © McGraw-Hill Higher Education. All rights reserved. 4-4 Bones Key bony landmarksKey bony landmarks –Acromion process –Glenoid fossa –Lateral border –Inferior angle –Medial border –Superior angle –Spine of the scapula From Seeley RR, Stephens TD, Tate P; anatomy and physiology, ed 7, New York, 2006, McGraw-Hill

5. © McGraw-Hill Higher Education. All rights reserved. 4-5 Joints Shoulder girdle (scapulothoracic)Shoulder girdle (scapulothoracic) –scapula moves on the rib cage –joint motion occurs at sternoclavicular joint & to a lesser amount at the acromioclavicular joint

6. © McGraw-Hill Higher Education. All rights reserved. 4-6 Joints Sternoclavicular (SC)Sternoclavicular (SC) –(multiaxial) arthrodial classification –Movements anteriorly 15 degrees with protractionanteriorly 15 degrees with protraction posteriorly 15 degrees with retractionposteriorly 15 degrees with retraction superiorly 45 degrees with elevationsuperiorly 45 degrees with elevation inferiorly 5 degrees with depressioninferiorly 5 degrees with depression

7. © McGraw-Hill Higher Education. All rights reserved. 4-7 Joints Sternoclavicular (SC)Sternoclavicular (SC) –Ligamentous support anteriorly by the anterior SC ligamentanteriorly by the anterior SC ligament posteriorly by the posterior SC ligamentposteriorly by the posterior SC ligament costoclavicular & interclavicular ligaments provide stability against superior displacementcostoclavicular & interclavicular ligaments provide stability against superior displacement

8. © McGraw-Hill Higher Education. All rights reserved. 4-8 Joints Acromioclavicular (AC)Acromioclavicular (AC) –arthrodial classification –20- to 30-degree total gliding & rotational motion accompanying other shoulder girdle & shoulder joint motions –supported by Coracoclavicular ligamentsCoracoclavicular ligaments Superior acromioclavicular ligamentSuperior acromioclavicular ligament Inferior acromioclavicular ligamentInferior acromioclavicular ligament –often injured

9. © McGraw-Hill Higher Education. All rights reserved. 4-9 Joints ScapulothoracicScapulothoracic –not a true synovial joint –does not have regular synovial features –movement depends on SC & AC joints which allows the scapula to move 25-degrees abduction-adduction25-degrees abduction-adduction 60-degrees upward-downward rotation60-degrees upward-downward rotation 55-degrees elevation-depression55-degrees elevation-depression –supported dynamically by its muscles –no ligamentous support

10. © McGraw-Hill Higher Education. All rights reserved. 4-10 Movements Focus on specific bony landmarksFocus on specific bony landmarks –inferior angle –glenoid fossa –acromion process Shoulder girdle movements = scapula movementsShoulder girdle movements = scapula movements

11. © McGraw-Hill Higher Education. All rights reserved. 4-11 Movements Abduction (protraction)Abduction (protraction) –scapula moves laterally away from spinal column Adduction (retraction)Adduction (retraction) –scapula moves medially toward spinal column

12. © McGraw-Hill Higher Education. All rights reserved. 4-12 Movements Downward rotationDownward rotation –returning inferior angle inferomedially toward spinal column & glenoid fossa to normal position Upward rotationUpward rotation –turning glenoid fossa upward & moving inferior angle superolaterally away from spinal column

13. © McGraw-Hill Higher Education. All rights reserved. 4-13 Movements DepressionDepression –downward or inferior movement, as in returning to normal position ElevationElevation –upward or superior movement, as in shrugging shoulders

14. © McGraw-Hill Higher Education. All rights reserved. 4-14 Movements Shoulder joint & shoulder girdle work together in carrying out upper extremity activitiesShoulder joint & shoulder girdle work together in carrying out upper extremity activities Shoulder girdle movement is not dependent upon the shoulder joint & its musclesShoulder girdle movement is not dependent upon the shoulder joint & its muscles

15. © McGraw-Hill Higher Education. All rights reserved. 4-15 Movements Shoulder girdle musclesShoulder girdle muscles –Stabilize scapula so the shoulder joint muscles will have a stable base from which to exert force for moving the humerus –Contract to maintain scapula in a relatively static position during shoulder joint actions –Contract to move shoulder girdle & to enhance movement of upper extremity when shoulder goes through extreme ranges of motion

16. © McGraw-Hill Higher Education. All rights reserved. 4-16 Movements For some shoulder girdle movements, scapula must rotate or tilt on its axisFor some shoulder girdle movements, scapula must rotate or tilt on its axis Lateral tilt (outward tilt)Lateral tilt (outward tilt) –during abduction –scapula rotates about its vertical axis resulting in posterior movement of medial border & anterior movement of lateral border Medial tilt (return from lateral tilt, inward tilt)Medial tilt (return from lateral tilt, inward tilt) –during extreme adduction –scapula rotates about its vertical axis resulting in anterior movement of medial border & posterior movement of lateral border

17. © McGraw-Hill Higher Education. All rights reserved. 4-17 Movements Anterior tilt (upward tilt)Anterior tilt (upward tilt) –rotational movement of scapula about frontal axis occurring during glenohumeral hyperextension –superior border moving anteroinferiorly & inferior angle moving posterosuperiorly Posterior tilt (downward tilt)Posterior tilt (downward tilt) –rotational movement of scapula about frontal axis occurring during glenohumeral hyperflexion –superior border moving posteroinferiorly & inferior angle moving anterosuperiorly

18. © McGraw-Hill Higher Education. All rights reserved. 4-18 Movements Synergy with muscles of glenohumeral jointSynergy with muscles of glenohumeral joint –As shoulder joint goes through more extreme ranges of motion, scapular muscles contract to move shoulder girdle so that its glenoid fossa will be in a more appropriate position from which the humerus can move –Without the accompanying scapula movement humerus can only be raised into approximately 90 degrees of total shoulder abduction & flexion

19. © McGraw-Hill Higher Education. All rights reserved. 4-19 Movements Synergy with muscles of glenohumeral jointSynergy with muscles of glenohumeral joint –This works through the appropriate muscles of both joints working in synergy to accomplish the desired action of the entire upper extremity –Ex. to raise our hand out to the side laterally as high as possible, the serratus anterior & trapezius (middle & lower fibers) muscles upwardly rotate scapula as supraspinatus & deltoid initiate glenohumeral abduction –This synergy between scapula & shoulder joint muscles enhances movement of entire upper extremity

20. © McGraw-Hill Higher Education. All rights reserved. 4-20 Shoulder Girdle Movements Elevation Depression Abduction Adduction UpwardRotation DownwardRotation

21. © McGraw-Hill Higher Education. All rights reserved. 4-21 Muscles 5 muscles primarily involved in shoulder girdle movements5 muscles primarily involved in shoulder girdle movements –All originate on axial skeleton & insert on scapula and/or clavicle –Do not attach to humerus & do not cause shoulder joint actions –Essential in providing dynamic stability of the scapula so it can serve as a relative base of support for shoulder joint activities such as throwing, batting, & blocking

22. © McGraw-Hill Higher Education. All rights reserved. 4-22 Shoulder Girdle Muscles 5 muscles primarily involved in shoulder girdle movements5 muscles primarily involved in shoulder girdle movements –Trapezius - upper, middle, lower –Rhomboid - deep –Levator scapula –Serratus anterior –Pectoralis minor - deep

23. © McGraw-Hill Higher Education. All rights reserved. 4-23 Shoulder Girdle Muscles Location & actionLocation & action –Anterior Pectoralis minor – abduction, downward rotation, & depressionPectoralis minor – abduction, downward rotation, & depression Subclavius – depressionSubclavius – depression –Posterior & laterally Serratus anterior – abduction & upward rotationSerratus anterior – abduction & upward rotation

24. © McGraw-Hill Higher Education. All rights reserved. 4-24 Shoulder Girdle Muscles Location & actionLocation & action –Posterior TrapeziusTrapezius Upper fibers – elevation & extension of the headUpper fibers – elevation & extension of the head Middle fibers – elevation, adduction, & upper rotationMiddle fibers – elevation, adduction, & upper rotation Lower fibers – adduction, depression, & upper rotationLower fibers – adduction, depression, & upper rotation Rhomboid – adduction, downward rotation, & elevationRhomboid – adduction, downward rotation, & elevation Levator scapulae – elevationLevator scapulae – elevation

25. © McGraw-Hill Higher Education. All rights reserved. 4-25 Nerves Shoulder girdle muscles primarily innervated by cervical & brachial plexusShoulder girdle muscles primarily innervated by cervical & brachial plexus From Seeley RR, Stephens TD, Tate P: Anatomy and physiology, ed 6, Dubuque, IA, 2003, McGraw-Hill

26. © McGraw-Hill Higher Education. All rights reserved. 4-26 Nerves Shoulder girdle muscles primarily innervated by cervical & brachial plexusShoulder girdle muscles primarily innervated by cervical & brachial plexus From Seeley RR, Stephens TD, Tate P: Anatomy and physiology, ed 6, Dubuque, IA, 2003, McGraw-Hill

27. © McGraw-Hill Higher Education. All rights reserved. 4-27 Nerves Branches of C3 & C4Branches of C3 & C4 –Trapezius –Levator scapula Spinal accessory nerveSpinal accessory nerve –Trapezius

28. © McGraw-Hill Higher Education. All rights reserved. 4-28 Nerves Dorsal scapula nerveDorsal scapula nerve –Levator scapula –Rhomboid Long thoracic nerve originating from C5, C6, & C7Long thoracic nerve originating from C5, C6, & C7 –Serratus anterior Medial pectoral nerve originating from C8 & T1Medial pectoral nerve originating from C8 & T1 –Pectoralis minor

29. © McGraw-Hill Higher Education. All rights reserved. 4-29 Trapezius muscle Lower fibers: depression, adduction, & upward rotation Upper fibers: elevation of scapula, extension & rotation of head Middle fibers: elevation, upward rotation, & adduction

30. © McGraw-Hill Higher Education. All rights reserved. 4-30 Levator scapulae muscle Elevates the medial margin of the scapula

31. © McGraw-Hill Higher Education. All rights reserved. 4-31 Rhomboid muscles - major & minor Downward rotation: from upward rotated position they draw scapula in downward rotation Elevation: slight upward movement accompanying adduction Rhomboid major & minor muscles work together Adduction (retraction): draw scapula toward spinal column

32. © McGraw-Hill Higher Education. All rights reserved. 4-32 Serratus anterior muscle Upward rotation: longer, lower fibers tend to draw inferior angle of scapula farther away from vertebrae, thus rotating scapula upward slightly Abduction (protraction): draws medial border of scapula away from vertebrae

33. © McGraw-Hill Higher Education. All rights reserved. 4-33 Pectoralis minor muscle Abduction (protraction): draws scapula forward & tends to tilt lower border away from ribs Depression: when scapula is rotated upward, it assists in depression Downward rotation: as it abducts, it draws scapula downward

34. © McGraw-Hill Higher Education. All rights reserved. 4-34 Subclavius muscle Stabilization & protection of sternoclavicular joint Abduction Depression

35. © McGraw-Hill Higher Education. All rights reserved. 4-35 Scapula Abduction Scapula move laterally away from spinous processes without rotationScapula move laterally away from spinous processes without rotation EX. Push-up & bench pressEX. Push-up & bench press AgonistsAgonists –Pectoralis minor –Serratus anterior

36. © McGraw-Hill Higher Education. All rights reserved. 4-36 Scapula Adduction Return from abductionReturn from abduction Occurs with retractionsOccurs with retractions AgonistsAgonists –Middle Trapezius –Rhomboids

37. © McGraw-Hill Higher Education. All rights reserved. 4-37 Scapula Upward Rotation Lateral & upward movementLateral & upward movement AgonistsAgonists –Middle Trapezius –Lower Trapezius –Serratus anterior

38. © McGraw-Hill Higher Education. All rights reserved. 4-38 Scapula Downward Rotation Downward & Medial MovementDownward & Medial Movement Glenoid Fossa is rotated downward when downward movement of shoulder joint occursGlenoid Fossa is rotated downward when downward movement of shoulder joint occurs EX. Lat Pulls - pulling wt. downEX. Lat Pulls - pulling wt. down AgonistsAgonists –Pectoralis Minor –Rhomboid

39. © McGraw-Hill Higher Education. All rights reserved. 4-39 Scapula Elevation Lifting scapula without rotation in anatomic positionLifting scapula without rotation in anatomic position Shoulder ShrugShoulder Shrug AgonistsAgonists –Levator Scapula –Upper Trapezius –Rhomboid

40. © McGraw-Hill Higher Education. All rights reserved. 4-40 Scapula Depression EX. DipEX. Dip AgonistsAgonists –Lower Trapezius –Pectoralis Minor

41. © McGraw-Hill Higher Education. All rights reserved. 4-41 Web Sites Radiologic Anatomy Browser http://radlinux1.usuf1.usuhs.mil/rad/iong/index.html – –This site has numerous radiological views of the musculoskeletal system. University of Arkansas Medical School Gross Anatomy for Medical Students http://anatomy.uams.edu/anatomyhtml/grossresources.html – –Dissections, anatomy tables, atlas images, links, etc. Loyola University Medical Center: Structure of the Human Body www.meddean.luc.edu/lumen/MedEd/GrossAnatomy/GA.html – –An excellent site with many slides, dissections, tutorials, etc., for the study of human anatomy Wheeless’ Textbook of Orthopaedics www.wheelessonline.com/ – –This site has an extensive index of links to the fractures, joints, muscles, nerves, trauma, medications, medical topics, lab tests, and links to orthopedic journals and other orthopedic and medical news.

42. © McGraw-Hill Higher Education. All rights reserved. 4-42 Web Sites Scapulothoracic Positions and Motion www.orthop.washington.edu/uw/scapulothoracic/tabID__3376/Ite mID__212/Articles/Default.aspx – –Scapula movements and movies The Physician and Sportsmedicine www.physsportsmed.com/issues/2003/0703/depalma.htm – –Detecting and Treating Shoulder Impingement Syndrome: The Role of Scapulothoracic Dyskinesis The Physician and Sportsmedicine www.physsportsmed.com/issues/2001/11_01/johnson.htm – –Acromioclavicular Joint Injuries: Identifying and Treating 'Separated Shoulder' and Other Conditions The Physician and Sportsmedicine www.physsportsmed.com/issues/1999/02_99/williams.htm – –Posterior Sternoclavicular Joint Dislocation

43. © McGraw-Hill Higher Education. All rights reserved. 4-43 Web Sites Baseball Almanac www.baseball-almanac.com/chapters/cap-ch8.shtml – –Coaching Adult Pitchers Lecture Topics in Kinesiology http://moon.ouhsc.edu/dthompso/namics/shoulder.htm – –Shoulder articulations, movements, and muscles that are within the shoulder girdle. Premiere Medical Search Engine www.medsite.com – –This site allows the reader to enter any medical condition and it will search the net to find relevant articles. Virtual Hospital www.vh.org – –Numerous slides, patient information, etc.