Shoulder Biomechanics
SC Joint
Sternoclavicular and
Acromioclavicular Joints
Saddle-type, but functions as ball &
socket
4 ligaments
Strong, but MOBILE
ROM=60° elevation and 25-30° anterior
and posterior movement
AC Joint
Plane synovial articulation
4 ligaments
Axioappendicular muscles cause
acromion of scapula to rotate on
acromial end of clavicle, which increases
scapulothoracic joint movement
Glenohumeral Joint (scapulohumeral
&scapulothoracic)
Ball & socket synovial joint
WIDE ROM, mobile, UNSTABLE
Cavity only accepts 1/3 of humeral head
Held in cavity with rotator cuff muscles
3 ligaments
Most freedom in body
Lateral rotation of humerus increases abduction ROM
Elevation & Depression
Clavicular elevation /depression(SC)
Clavicular Elevation (SC joint)
Subtle anterior/posterior tipping (AC)
Subtle internal/external rotation (AC)
Upward & Downward Rotation (abd/add)
2:1 humoral:scapular
Upward/downward rotation (AC)
Clavicular elevation/depression (SC)
Subtle posterior/anterior rotation (SC)
Protraction & Retraction
Clavicular protraction/retraction (SC)
Subtle internal/external rotation (AC)
Winging
Excessive internal rotation (AC)
https://www.youtube.com/wa
tch?v=rRIz6oOA0Vs
Scapula loss of contact with thorax, medial border prominence results
Winging
Upward Rotation (AC)
Protraction (SC)
Group 1
Group 2
Group 3
Group 4
Trunk to Head
Trunk to scapula
Trunk to Humerus
Shoulder Girdle to Humerus
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SCM
Subclavius
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Scapular Movement
Elevation
Depression
Protraction
Retraction
Upward Rotation
Downward Rotation
Trapezius
Levetor
scapulae
Serratus
anterior
Rhomboids
major &
minor
Pectoralis
minor
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Latissimus
dorsi
Pectoralis
major
Deltoideus
Subscapularis*
Supraspinatus*
Infraspinatus*
Teres minor*
Teres major
Muscles Producing Movement
Trapezius (superior part)
Levator Scapulae
Rhomboids
Pectoralis major (inferior sternocostal head)
Latissimus Dorsi
Trapezius (inferior part)
Serratus anterior (inferior part)
Pectoralis minor
Serratus anterior
Pectoralis major/minor
Trapezius (middle part)
Rhomboids
Latissimus dorsi
Serratus anterior (inferior part)
Trapezius (superior part)
Trapezius (inferior part)
Latissimus Dorsi
Levator scapulae
Rhomboids
Pectoralis minor
Pectoralis major (inferior sternocostal head)
Tests:
Hawkins-Kennedy Test
Neer Impingement Test
Research Article
Evaluated the effectiveness of FES in
shoulder subluxation and pain for
patients who have developed hemiplegia
due to stroke
Shoulder pain measured during resting,
passive range of motion (PROM) and
active range of motion (AROM) using
visual analog scale (VAS)
50 patients with shoulder subluxation
and shoulder pain randomly split into
either the study group or the control
group
FES applied to supraspinatus and
posterior deltoid muscles
Study groupconventional rehabilitation
therapy and applied FES
Control group conventional
rehabilitation therapy
Results decreased subluxation levels in the
study group compared to the control group
Conclusion Conventional therapy with FES
is more beneficial than just conventional
therapy alone when examining shoulder
subluxation
Shoulder Instability
Most common are anterioinferior
capsololabral auvlsions (Degen,2013), more
commonly known as Bankart Lesions
Glenoid Bone Grafting
Bristow Coracoid Transfer
Latarjet Coracoid Transfer (subscapularis)
References
1)
Degen, R. M., Giles, J. W., Thompson, S. R., Litchfield, R. B., & Athwal, G. S. (2013).
Biomechanics of Complex Shoulder Instability. Clinics In Sports Medicine, 32(4), 625-636.
doi:10.1016/j.csm.07.002
2)
Itoi E, Lee SB, Berglund LJ, et al. (2000). The Effect of a Glenoid Defect on Anteroinferior
Stability of the Shoulder After Bankart Repair: a cadaveric study. J Bone Joint Surg Am,82(1),
35–46.
3)
Koyuncu, E., Nakipoglu-Tuzer, G., Dogan, A., and Ozgirgin, N. (2010). The effectiveness of
functional electrical stimulation for the treatment of shoulder subluxation and shoulder pain in
hemiplegic patients: A randomized controlled trial. Disability and Rehabilitation, 32(7), 560566
4)
Moore, K., Agur, A., and Dalley, A. . (2015). Essential Clinical Anatomy. Lippincott Williams &
Wilkins, 5, 465-69
5)
Netter. F. (2014). Atlas of Human Anatomy. Saunders Elsevier, (6), 405-411, 417
6)
Tortora, G., Derrickson, B. (2012) Principles of Anatomy and Physiology. Biological Science
Textbook Inc, 13, 614-615.