i (and/or my co-authors) have something to disclose. · detailed disclosure information is...
TRANSCRIPT
![Page 1: I (and/or my co-authors) have something to disclose. · Detailed disclosure information is available via: The course syllabus, or AAOS Disclosure Program on the AAOS website at](https://reader030.vdocument.in/reader030/viewer/2022032614/5bc7ef7d09d3f25c258c67e3/html5/thumbnails/1.jpg)
12/28/2016
1
Shoulder Anatomy and Biomechanics
Nikhil N Verma, MDSection Head: Sports Medicine
Professor, Department of OrthopedicsRush University
Team Physician, Chicago White Sox and Bulls
Shoulder Anatomy
And Biomechanics
Shoulder Anatomy and Biomechanics
I (and/or my co-authors) have something to
disclose.
Detailed disclosure information is available via:
The course syllabus, or
AAOS Disclosure Program on the AAOS website athttp://www.aaos.org/disclosure
Shoulder Anatomy and Biomechanics
Overhead Throwing Motion
![Page 2: I (and/or my co-authors) have something to disclose. · Detailed disclosure information is available via: The course syllabus, or AAOS Disclosure Program on the AAOS website at](https://reader030.vdocument.in/reader030/viewer/2022032614/5bc7ef7d09d3f25c258c67e3/html5/thumbnails/2.jpg)
12/28/2016
2
Shoulder Anatomy and Biomechanics
Kinetic Chain
• Coordinated body movements to impart energy to a body part or object
• Large to Small Muscles
• Proximal to Distal Action
• Action is funneled through the scapula
Shoulder Anatomy and Biomechanics
Cocking: Early and Late
• Ends as front foot hits ground
• Maximum ER at shoulder
Flexion at elbow
Shoulder Anatomy and Biomechanics
Acceleration Phase
• Shortest, fastest phase
• In as little as .145 sec:4 to 85 mph
• Angular Velocity up to 7000 deg/sec
• Violent IR of shoulder to ball release
![Page 3: I (and/or my co-authors) have something to disclose. · Detailed disclosure information is available via: The course syllabus, or AAOS Disclosure Program on the AAOS website at](https://reader030.vdocument.in/reader030/viewer/2022032614/5bc7ef7d09d3f25c258c67e3/html5/thumbnails/3.jpg)
12/28/2016
3
Shoulder Anatomy and Biomechanics
Deceleration Phase
• Ball Release thru maximum IR of shoulder
• Must dissipate the energy of the action
• Posterior shoulder muscles eccentrically contract
Shoulder Anatomy and Biomechanics
Shoulder Complex
Shoulder Joint Complex:
• Sternoclavicular joint
• Acromioclavicular joint
• Glenohumeral joint
• Scapulothoracic joint
Shoulder Anatomy and Biomechanics
Glenohumeral Joint
• Partially Conforming Joint– Bone mismatch
ratio 0.6
– Articular mismatch ratio 0.9
• Limited Constraint
• High Risk of Instability
![Page 4: I (and/or my co-authors) have something to disclose. · Detailed disclosure information is available via: The course syllabus, or AAOS Disclosure Program on the AAOS website at](https://reader030.vdocument.in/reader030/viewer/2022032614/5bc7ef7d09d3f25c258c67e3/html5/thumbnails/4.jpg)
12/28/2016
4
Shoulder Anatomy and Biomechanics
Humeral and Glenoid Retroversion
• Humeral Retroversion 20-30°
– May be increased 10-15° in the overhead athlete
• Glenoid Retroversion 1-10°
– May be Increased 5-7° in the overhead athlete
Shoulder Anatomy and Biomechanics
•Non weight-bearing
• Thin articular cartilage
• Defects often asymptomatic
•Articular Lesions are
Relatively Uncommon in
Baseball Despite High
Functional Demand
GH Articular CartilageGH Articular Cartilage
Shoulder Anatomy and Biomechanics
Sternoclavicular JointConnects shoulder complex to axial skeleton
Incongruous joint
Articular disc and costoclavicular ligaments are main stabilizers of the SC joint
Articular disc prevents clavicle from translating medially
![Page 5: I (and/or my co-authors) have something to disclose. · Detailed disclosure information is available via: The course syllabus, or AAOS Disclosure Program on the AAOS website at](https://reader030.vdocument.in/reader030/viewer/2022032614/5bc7ef7d09d3f25c258c67e3/html5/thumbnails/5.jpg)
12/28/2016
5
Shoulder Anatomy and Biomechanics
Sternoclavicular JointAllows the following clavicular movements:
Elevation
Depression
Protraction
Retraction
Long-axis rotation
Shoulder Anatomy and Biomechanics
Acromioclavicular JointFormed by articulation of convex clavicle and concave acromion
Oblique orientation
Contributes to total arm movement
Transmits forces between clavicle and acromion
Shoulder Anatomy and Biomechanics
Acromioclavicular Joint3 axis of movement
Vertical, frontal, and sagittal
Primary stabilizer of the AC joint: CC ligamentsPrevents dissociation of clavicle from acromion
CC ligaments:Conoid: more medial
Limits upward movement of the clavicle
Trapezoid: more lateralPrevents overriding of clavicle on acromion
![Page 6: I (and/or my co-authors) have something to disclose. · Detailed disclosure information is available via: The course syllabus, or AAOS Disclosure Program on the AAOS website at](https://reader030.vdocument.in/reader030/viewer/2022032614/5bc7ef7d09d3f25c258c67e3/html5/thumbnails/6.jpg)
12/28/2016
6
Shoulder Anatomy and Biomechanics
Glenohumeral JointFunction
-Rotator Cuff-Articular Cartilage-Extra-Articular Muscles(Pec Major, Latissimus, Deltoid)
Stability
-Labrum-Capsule-Rotator Cuff
Shoulder Anatomy and Biomechanics
Labrum• Ring of Fibrocartilage and fibrous
tissue
• Attachment site of glenohumeralligaments
• Function– Primary Function is Stability
– Improved stability with added glenoid depth
• Origin of long head of biceps
Shoulder Anatomy and Biomechanics
• Anterior Labrum– Provides restraint
against anterior translation
– Injured via traumatic dislocation
• Posterior Labrum– Batters Shoulder
– Lead Shoulder with Posterior Force
![Page 7: I (and/or my co-authors) have something to disclose. · Detailed disclosure information is available via: The course syllabus, or AAOS Disclosure Program on the AAOS website at](https://reader030.vdocument.in/reader030/viewer/2022032614/5bc7ef7d09d3f25c258c67e3/html5/thumbnails/7.jpg)
12/28/2016
7
Shoulder Anatomy and Biomechanics
SLAP: Anatomy
•Superior
•Labrum
•Anterior to
•Posterior
Shoulder Anatomy and Biomechanics
AnatomyVasculature & Neuroanatomy
MistakeBad biology and hurts without mechanical instability
No Blood Supply from Glenoid
Suprascapular n
Axillary n
No Mechanoreceptors
Suprascapular a Circumflex Scap a
Post Hum Circumflex a
Shoulder Anatomy and Biomechanics
AnatomyLabral Sulcus
30% 30% 20% 20%
Smith, 1996; Kreitner, 1998, Waldt, 2006Smith, 1996; Kreitner, 1998, Waldt, 2006
![Page 8: I (and/or my co-authors) have something to disclose. · Detailed disclosure information is available via: The course syllabus, or AAOS Disclosure Program on the AAOS website at](https://reader030.vdocument.in/reader030/viewer/2022032614/5bc7ef7d09d3f25c258c67e3/html5/thumbnails/8.jpg)
12/28/2016
8
Shoulder Anatomy and Biomechanics
SLAP Anatomy
• Meniscoid at superior aspect• Sulcus
30% 30% 20% 20%
Phaler JSES 2003
< 10 yo 30 - 50 yo >60 yo
No separation
Shoulder Anatomy and Biomechanics
What is the Function of the Superior Labrum?
Shoulder Anatomy and Biomechanics
5.46.8
3.4
9.3 8.9
4.8
0.0
2.0
4.0
6.0
8.0
10.0
12.0
14.0
AnteriorTranslation
PosteriorTranslation
ABER
Mil
lim
eter
s
Anterior SLAP Lesion
Baseline
SLAP6.2 6.5
4.7
10.69.9
7.6
0.0
2.0
4.0
6.0
8.0
10.0
12.0
14.0
16.0
AnteriorTranslation
PosteriorTranslation
ABER
Mil
lim
eter
s
Posterior SLAP Lesion
Baseline
SLAP
![Page 9: I (and/or my co-authors) have something to disclose. · Detailed disclosure information is available via: The course syllabus, or AAOS Disclosure Program on the AAOS website at](https://reader030.vdocument.in/reader030/viewer/2022032614/5bc7ef7d09d3f25c258c67e3/html5/thumbnails/9.jpg)
12/28/2016
9
Shoulder Anatomy and Biomechanics
Superior Labrum: Origin of long head biceps
Vangsness, JBJS Br 1994
• 100 shoulders• 40% to 60% origin from supraglenoid tubercle• Rest from Labrum
Also means 40% to 60% comes from superior labrum
Shoulder Anatomy and Biomechanics
Vangsness, JBJS Br 1994
22% 33% 37% 8%All posterior Most posterior = ant & posterior Most anterior
Origin of long head biceps
Shoulder Anatomy and Biomechanics
Biceps: Anatomic Considerations
•Intrarticular, Extrasynovial• Intrarticular Biceps Length
(34.4+4.24mm)• Arm in adduction and neutral
rotation
•Extra-articular: Approximate 5cm• Groove Width = 6.1+1.5mm• Groove Length = 30.6+5.7mm
• •Cannot Be seen • arthorscopically
•May Be a Cause of Anterior Shoulder Pain
•Requires Accurate Clinical Exam
Coracoid Process
Coracohumeral Ligament
Rotator Interval
Biceps Tendon
![Page 10: I (and/or my co-authors) have something to disclose. · Detailed disclosure information is available via: The course syllabus, or AAOS Disclosure Program on the AAOS website at](https://reader030.vdocument.in/reader030/viewer/2022032614/5bc7ef7d09d3f25c258c67e3/html5/thumbnails/10.jpg)
12/28/2016
10
Shoulder Anatomy and Biomechanics
Question: What is the functional role of Biceps?
•Summary:
• Comparative anatomy and EMG suggest minimal role for biceps in shoulder activities,
•BUT Biomechanical data suggest a secondary but
possibly important role, at end ROM.
(e.g. overhead sports? Instability?)
Shoulder Anatomy and Biomechanics
Pain Generator
Shoulder Anatomy and Biomechanics
Capsule
• Glenohumeral capsule provide stability to the joint
• Individual ligaments are thickening of the capsular tissue
• Anterior– CoracoHumeral Ligament
– Superior GlenohumeralLigament
– Middle Glenohumeral Ligament
– Anterior Band Inferior Glenohumeral Ligament (AIGHL)
• Posterior– Posterior Band Inferior
Glenohumeral Ligament (PIGHL)
![Page 11: I (and/or my co-authors) have something to disclose. · Detailed disclosure information is available via: The course syllabus, or AAOS Disclosure Program on the AAOS website at](https://reader030.vdocument.in/reader030/viewer/2022032614/5bc7ef7d09d3f25c258c67e3/html5/thumbnails/11.jpg)
12/28/2016
11
Shoulder Anatomy and Biomechanics
Glenohumeral Capsule
• Anterior Laxity– Repetitive
Abduction / External Rotation
• Posterior Contracture– Deceleration
During Follow Through
Shoulder Anatomy and Biomechanics
APMAX External RotationI
S
I: Intact
S: Stretched
C: Posterior Contracture
C
I
S
S
I
C
Humeral Head Position with Respect to the Glenoid Following Maximum External Rotation for Intact Capsule, Stretched Capsule, and Simulated Posterior Capsular Contracture
Humeral Head
-10
-9
-8
-7
-6
-5
-18 -17 -16 -15 -14
Posterior Translation (mm)
Inferio
r Tran
slation
(mm
)
*S
IC
* p<0.05
Lee, Tibone AJSM 2012
Shoulder Anatomy and Biomechanics
Capsular Rupture
![Page 12: I (and/or my co-authors) have something to disclose. · Detailed disclosure information is available via: The course syllabus, or AAOS Disclosure Program on the AAOS website at](https://reader030.vdocument.in/reader030/viewer/2022032614/5bc7ef7d09d3f25c258c67e3/html5/thumbnails/12.jpg)
12/28/2016
12
Shoulder Anatomy and Biomechanics
Rotator Cuff Tear: Anatomy
Anterior Posterior
Shoulder Anatomy and Biomechanics
CURTIS et alArthroscopy 2006
Infraspinatus Supraspinatus
Shoulder Anatomy and Biomechanics
![Page 13: I (and/or my co-authors) have something to disclose. · Detailed disclosure information is available via: The course syllabus, or AAOS Disclosure Program on the AAOS website at](https://reader030.vdocument.in/reader030/viewer/2022032614/5bc7ef7d09d3f25c258c67e3/html5/thumbnails/13.jpg)
12/28/2016
13
Shoulder Anatomy and Biomechanics
Rotator Cuff Cable
Shoulder Anatomy and Biomechanics
Rotator Cuff
Provides dynamic stability to GH joint
Composed of:
• Subscapularis anteriorly
• Supraspinatus superiorly
• Teres minor and Infraspinatus posteriorly
Shoulder Anatomy and Biomechanics
Internal Impingement
Halbrecht, J. L., Tirman, P., & Atkin, D. (1999). Internal impingement of the shoulder: comparison of findings between the throwing and nonthrowing shoulders of college baseball players. Yjars, 15(3), 253–258.
![Page 14: I (and/or my co-authors) have something to disclose. · Detailed disclosure information is available via: The course syllabus, or AAOS Disclosure Program on the AAOS website at](https://reader030.vdocument.in/reader030/viewer/2022032614/5bc7ef7d09d3f25c258c67e3/html5/thumbnails/14.jpg)
12/28/2016
14
Shoulder Anatomy and Biomechanics
What can happen?
Tension during the deceleration phase of the pitch cycle can cause injuries to the cuff
Shoulder Anatomy and Biomechanics
Suprascapular Nerve anatomy:Upper Trunk of the Brachial Plexus (C5, C6)
…50% have contributions from C4-Afferent Fibers to posterior AC and GH joint
Shoulder Anatomy and Biomechanics
Suprascapular Nerve
• Traverses the Scapular Notch under the Transverse Ligament
• Traverses the SpinoglenoidNotch
• Both May be Sites of impingement
![Page 15: I (and/or my co-authors) have something to disclose. · Detailed disclosure information is available via: The course syllabus, or AAOS Disclosure Program on the AAOS website at](https://reader030.vdocument.in/reader030/viewer/2022032614/5bc7ef7d09d3f25c258c67e3/html5/thumbnails/15.jpg)
12/28/2016
15
Shoulder Anatomy and Biomechanics
Suprascapular Nerve Entrapment
• Mixed Motor/Sensory Nerve C5/C6
• Incidence
• -4% In Pitchers
• -0.2% In Position Players
• -Most Common at Spinoglenoid Notch
Shoulder Anatomy and Biomechanics
AUGUST 4-6GRAND HYATTCHICAGO
www.FOREONLINE.org
Join us in Chicago
Shoulder Anatomy and Biomechanics
Thank You
Chicago