Shoulder Girdle

What is the normal angle of inclination of the humeral head?

130-150 degrees from the shaft in the frontal plane

What is the normal angle of torsion for the humerus?

~30 degrees of retroversion (posterior torsion) in the transverse plane

What nerve passes immediately posterior to the surgical neck of the humerus?

The axillary nerve

What anatomical landmark separates the greater and lesser tubercles

The intertubercular (bicipital) groove

Where is the anatomical neck located?

Immediately distal to the head, before the tubercles

What clinical structure marks the transition to the narrow shaft?

The surgical neck the humerus

What neurovascular structure wraps around the surgical neck?

The axillary nerve

Name the greater tubercle superior facet attachment.

Supraspinatus tendon.

Name the greater tubercle middle facet attachment.

Infraspinatus tendon.

Name the greater tubercle inferior facet attachment.

Teres minor tendon.

What muscle attaches to the lesser tubercle?

Subscapularis muscle.

Name the muscle attaching to the intertubercular lateral lip.

Pectoralis major.

Name the muscle attaching to the intertubercular medial lip.

Teres major.

Name the muscle attaching to the intertubercular floor

Latissimus dorsi

What muscle attaches distally to the deltoid tuberosity?

Deltoid muscle

Where can suprascapular neuropathy occur in overhead athletes?

At the spinoglenoid (greater scapular) notch

What lesion is associated with this notch neuropathy?

Bennett's lesion

Describe Type I acromion morphology

Normal / flat structure

Describe Type II acromion morphology

Curved structure

Describe Type III acromion morphology

Hooked structure

Name the two inferior lateral clavicle landmarks

Conoid tubercle and trapezoid line

Why is the SC joint structurally critical?

It solely attaches upper extremity to axial skeleton

What is the SC joint classification?

Synovial saddle (sellar) joint.

What type of cartilage is the SC articular disc?

Fibrocartilage dividing it into two compartments.

What is resisted by the interclavicular ligament?

Inferior translation of the clavicles.

What is resisted by the costoclavicular ligament?

Elevation of the clavicle

What is the AC joint classification?

Synovial planar joint.

What does the acromioclavicular ligament resist?

Superior translation of joint members.

What happens in a full AC joint separation?

Both acromioclavicular and coracoclavicular ligaments tear

What is the GH joint classification?

Synovial spheroidal (ball-and-socket) joint

What is the function of the SGHL?

Limits inferior translation and external rotation

When does the MGHL primarily limit anterior translation?

When the arm is abducted to ~45°

What is the primary static stabilizer abducted >45°?

Inferior Glenohumeral Ligament (IGHL) complex

What does the coracohumeral ligament limit?

Inferior translation from gravity and external rotation

What are the SC joint shapes in the frontal plane?

Convex clavicle on concave manubrium

State SC arthrokinematics during elevation

Superior roll with inferior glide

State SC arthrokinematics during depression

Inferior roll with superior glide

What are the SC joint shapes in the sagittal plane?

Concave clavicle on convex manubrium

State SC arthrokinematics during protraction

Anterior roll and anterior glide (same direction)

State SC arthrokinematics during retraction

Posterior roll and posterior glide (same direction)

State GH arthrokinematics during abduction

Superior roll with inferior glide

State GH arthrokinematics during external rotation (ER)

Posterior roll with anterior glide

State GH arthrokinematics during internal rotation (IR)

Anterior roll with posterior glide

What is the SC joint close-packed position?

Maximum shoulder elevation

What is the AC joint close-packed position?

Shoulder abducted to 30°

What is the loose-packed position for SC and AC?

Standard anatomical position

What is the capsular pattern of restriction for the glenohumeral (GH) joint, ordered from most limited to least limited?

• 1. External Rotation (ER) – Most severely restricted.

• 2. Abduction (ABD) – Second most restricted.

• 3. Internal Rotation (IR) – Least restricted (but still limited).

  Every Athlete Injures Rotator-cuffs (ER>ABD>IR).

What ligament is responsible for compressing the suprascapular nerve at the suprascapular notch?

The superior transverse scapular ligament.

Describe the curves of the lateral vs. medial portions of the clavicle from an anterior view.

• Lateral portion: Concave anteriorly (flat acromial end).

• Medial portion: Convex anteriorly (bulbous sternal end).

How do the superior and inferior surfaces of the clavicle look texturally?

The superior surface is smooth; the inferior surface is roughened for ligamentous attachments.

True or False: The long head of the biceps brachii tendon is intracapsular but extrasynovial.

True. It passes through an opening between the tubercles of the humerus.

Which region of the GH joint capsule is the most reinforced, and which is the least reinforced?

• Most reinforced: Anterior capsule.

• Least reinforced: Inferior capsule.

Clinically, how much joint distraction is normally available at the GH joint due to its loose capsule?

Greater than 1 inch of distraction

Name the three distinct openings found in the GH joint capsule

1. Subscapularis bursa

2. Infraspinatus bursa

3. Between the tubercles of the humerus (for the long head of the biceps)

What alternative name is given to the glenohumeral ligament complex due to its appearance?

The "Z ligament"

What are the exact proximal and distal attachments of the "Z ligament" (GH ligament)?

• Proximal Attachment (PA): Superior-medial glenoid margin.

• Distal Attachment (DA):

  • Superior portion: Lesser tubercle.

  • Middle portion: Inferior aspect of the lesser tubercle.

  • Inferior portion: Inferior aspect of the anatomical neck.

Together, what movements do all parts of the "Z ligament" check?

They check anterior glide and external rotation (lateral rotation) of the GH joint