Lecture 1-Superficial Back & Scapular Region

Question 1

Sternoclavicular Joint

Answer 1

-Manubrium of sternum to clavicle
-connects upper limb to axial skeleton
-Synovial joint w an Articular Disc (helps prevent bones from hitting/grinding)
Ligaments: -Interclavicular ligament -Anterior and Posterior sternoclavicular ligaments -Costoclavicular ligament
Motions: -Predominantly in anetroposterior and vertical planes -Some rotation
Muscles: -NO muscles cross this joint

Question 2

Acromioclavicular joint

Answer 2

-Acromion process of scapula to clavicle
-connects upper limb to axial skeleton
-Synovial joint
-Stability of AC joint is function of coracoclavicular ligaments
Ligaments: -Acromioclavicular ligament -Coracoclavicular ligament (made of trapezoid and conoid ligaments)
Motions: -Anteroposterior and vertical planes -Some slight axial rotation

Question 3

Glenohumeral joint

Answer 3

• Glenoid cavity (fossa) of scapula to head of humerus
• connects upper limb to axial skeleton
• Articulation of humeral head to glenoid cavity
• Glenoid cavity “deepend” by glenoid labrum (fibrocartilage), prevents bones from grinding
• Provides stability

Question 4

Upper Limb Attachment to Axial Skeleton

Answer 4

• Sternoclavicular joint
• Acromioclavicular joint
• Glenohumeral joint
• Thoracoscapular joint

Question 5

Shoulder Separation

Answer 5

• Disclocation of AC joint, usually from fall/sharp blow to top of shoulder
• AC joint is weak bc has lots of mobility
• After separation, weight of arm dsiplaces clavicle from acromion

Question 6

Shoulder Dislocations

Answer 6

• GH joint most susceptible to dislocations in abduction and external rotation
• Once out of glenoid cavity, pec major pulls humerus anterosupiorly, axial nerve may be damaged

Question 7

Thoraco-scapular Joint

Answer 7

-Superfical back muscles allow scapula to move in: -elevation/depression -protraction/retraction -upward/downward rotation

Question 8

Snapping Scapula

Answer 8

• aka scapulathoracic bursitis/crepitus
• caused by bony alteration or inflamed soft tissue
• painful or painless
• chronic (microtrauma) or acute (macrotrauma)
• often from overuse, worse w overhead movement

Question 9

Trapezius

Answer 9

-Superficial back
Originates: occipital bone, nuchal ligament, and thoracic spinous processes
Inserts: lateral clavicle, acromion, and spine of scapula,
Innervated by: Accessory Nerve (CN XI)
Action: -Descending (superior) part contraction= elevation of scapula
-Ascending (inferior) part contraction = depression
- Middle part contraction = retraction
-All three part contraction = strong retraction

Question 10

Latissimus dorsi

Answer 10

-Superficial Back
Originates: Thoracolumbar fascia
Inserts: Intertubercular groove of humerus (anterior part)
Innervated by : Thoracodorsal nerve
Action: Contraction will adduct humerus, slight inner rotation

Question 11

Levator Scapulae

Answer 11

-Superficial Back
-located above scapula
Originates: Transverse processes of Cv 1-4
Inserts: medial border of scapula above spine
Innervated by: Dorsal Scapular Nerve
Action: Elevates scapula

Question 12

Rhomboideus Minor and Major

Answer 12

-Superficial Back
Originates: lower nuchal ligament and Cv7-Tv1 (r. minor) or Tv2-5 (r. major)
Inserts: medial border of scapula
Innervated by: Dorsal Scapular Nerve (C5)
Action: -R. minor will elevate
-R. major will retract

Question 13

Intermediate Back Muscles

Answer 13

• Respiratory in function
• Serratus muscles dont touch scapula, attach ribs to spine
• All Innervated by segmental ventral/anterior rami of spinal nerves

Question 14

Serratus Posterior Superior

Answer 14

-Intermediate Back Muscle 
Originates: Nuchal ligament and Tv1-3 
Inserts: Ribs 2-5
Innervated by:  segmental ventral/anterior rami of spinal nerves 
Action: Elevates upper ribs

Question 15

Serratus Posterior Inferior

Answer 15

-Intermediate Back Muscle 
Originates: Tv11-L2
Inserts: Ribs 9-12
Innervated by:  segmental ventral/anterior rami of spinal nerves 
Action: Depresses lower ribs

Question 16

Serratus Anterior

Answer 16

-Intermediate Back Muscle
Originates: Ribs 1-9
Inserts: Medial border of scapula (costal surface)
Innervated by: long thoracic nerve (is very superficial)
Action: -protraction and rotation of scapula -keeps medial border and inferior angle of scapula opposed to thoracic wall

Question 17

Winged Scapula

Answer 17

• Injury to long thoracic nerve
• Serratus anterior cannot contract, scapula pulls away from thorax when pushing against wall
• No abduction past horizontal bc serratus ant. helps rotate scapula upward)

Question 18

Movements of Scapula

Answer 18

Elevation: -Superficial fibers of trapezius -Levator scapula -Rhomboid minor -Rhomboid major
Depression: Anterior: -pec. minor -serratus anterior (inferior part) Posterior: -Trap (inferior part) -serratus anterior (inferior part)
Protraction: -Pec minor -Serratus anterior
Retraction: -Trap (middle part)
-Rhom. minor -Rhom. major
-Lat. dorsi (doesnt touch scapula, but can pull back humerus)
-Superior rotation: -Trap (superior part, pulls acromion toward neck) -Trap (inferior part, pulls medial part of scapula down) -Serratus anterior (inferior part, pulls scapula down/outward)
Inferior rotation: Anterior: - Pec. minor Posterior: -levetator scaopulae -Rhom. major -Rhom minor -Lat. dorsi