Biomechanics Lecture 02

Biomechanics Lecture 02 ( Upper Extremity)

Bursa:

Fibrous sacs.

Sacs inner walls secrete fluid.

Reduce friction b/w layers of collagenous tissue.

Subacromial, subcoracoid, subscapularis.

Subcoracoid and subscapular bursa: prevents friction between subscapularis muscle and neck of scapula

Subacromial bursa: lies b/w acromian process of scapula  and CCL (coracoclavicular ligament) above and humeral head below .

Prevent friction b/w humeral head,RC and above acromian process.

 

The Stable Shoulder

1.Static Restraint

Bone

• Glenoid
• Humerus

Ligaments

Labrum

Capsule

Negative pressure

Adhesion

 

2.Dynamic restraint

 

Rotator cuff

• Concavity
• compression

biceps

deltoid

scapula rotators
SCAPULAR MUSCLES

• Scapular muscles function.
• 1.Contract and stabilize  the shoulder joint. e.g. suitacse lifting.
• 2. Facilitate the mov of GH and UE .e.g. throwing of a ball.

MAJOR FLEXOR OF SHOULDER

1. Clavicular pectoralis major
2. Anterior deltoid
3. Coracobrachialis

MAJOR EXTENSIOR OF SHOULDER

1. Sternal pectoralis major
2. Latissimus dorsi
3. Teres major

MAJOR ABDUCTORS OF SHOULDER

1. Middle deltoid
2. Supraspinatus

MAJOR ADDUCTORS OF SHOULDER

1. Sternal pectoralis major
2. Latissimus dorsi
3. Teres major

      MAJOR HORIZONTAL ADDUCTORS

1. Pectoralis major
2. Anterior deltoid
3. coracobrachialis

      MAJOR HORIZONTAL ABDUCTORS

1. middle and posterior deltoid
2. infraspinatus
3. teres minor