muscles and apllications Flashcards Preview

PHTY1200 - Analysis of movement of the upper limb 1 > muscles and apllications > Flashcards

Flashcards in muscles and apllications Deck (13):

Muscles of the shoulder girdle

Shoulder girdle to skull, neck and trunk
• Scapula to humerus
• Trunk to humerus


Shoulder girdle to skull, neck and trunk

Serratus anterior
• Trapezius – 3 parts
• Rhomboid major and minor • Levator scapulae
• Pectoralis minor
• Subclavius


scap to humerus muscles

• Deltoid
• Supraspinatus
• Infraspinatus
• Teres minor
• Subscapularis
• Teres major
• Coracobrachialis


Trunk to humerus muscles

pec major
lat dorsi


scap muscles

little redundancy (i.e., muscles which can produce similar movements when they work).
• This is very important as clinically it means that if a muscle becomes unable to function (e.g., due to nerve injury), the effects are significant to function of the scapula and therefore to the shoulder complex and upper limb.


Rotator cuff muscles

• Infraspinatus
• Teres minor
• Subscapularis
• Maximal strength working off
a retracted and stable scapula


Action of long head of biceps

Tendon runs in the inter‐tubercular groove
• Stabilised by the transverse humeral ligament – SS and SS
• Becomes intra‐capsular and attaches to the superior labrum
• LHB, when tensioned, produces a downward and inward force on the humeral head.
• Thus assists in head of humerus depression and stabilising the humeral head in the fossa, preventing subluxation and anterior translation.


Action of deltoid

1. During early stages of elevation ‐ superior force decreasing subacromial space counteracted by rotator cuff contraction
2. At later stages of elevation ‐ deltoid increases compression, increases stability


Some clinical applications

Potential for instability
• Glenohumeral dislocation
Macro or repeated micro trauma can easily lead to dislocation/instability.
Often becomes recurrent. Most often anterior – GH joint.


AC joint dislocation

Reduced horizontal adduction
Reduced AC joint stability and therefore impaired coupling of movement between scapula and clavicle



Many contributing factors including:
Anatomical factors
Shoulder girdle posture
Altered muscle control
Repetitive activity
Underlying instability
Bony spur - body grows bone where cartilage should be
• Alterations in any/combinations/all of these can lead to impingement of structures (e.g., subacromial structures).


• Rotator cuff tears

Due to trauma or degenerative
Often causes pain and loss of ROM and function. Altered control of humeral head position
side note: when rotator cuff muscles don’t stabilise position of HH, other muscles can


Take home message

Movement of shoulder complex takes place at multiple joints.
• Full available ROM of all joints is therefore necessary for full ROM and function of the shoulder complex and UL.
• Stability of the scapulothoracic joint and maintenance of scapulohumeral rhythm is imperative for functional movements of the UL as it provides a stable platform off which the UL can function.
• Disruption to components of stability at any of the shoulder complex joints can significantly impair functional movement.