Scapulohumeral
Muscles
Overview
Six
Scapulohumeral
muscles
are
relatively short muscles that pass from the
scapula to the Humerus and act on the
glenohumeral joint:4. Teres Major.
1. Deltoid.
2. Supraspinatus.
5. Teres Minor.
3. Infraspinatus.
6. Subscapularis.
Deltoid
Muscle
Deltoid
Muscle
Muscle Attachments
Muscle Attachments
Innervation
Nerves:Axillary Nerve.
Roots:(C5, C6)
Main Actions
Clavicular (anterior) part: flexes and
medially rotates arm assists Pectoralis
major muscle.
Acromial (middle) part: abducts arm from
°
15 Angle.
Spinal (posterior) part: extends & laterally
rotates arm assists Latissimus Dorsi muscle.
To Test the Muscle
To test the Deltoid (or the function of
the axillary nerve that supplies it), the
arm is abducted, starting from
approximately 15°, against resistance.
If acting normally, the deltoid can
easily be seen and palpated.
Teres
Major
Muscle
Teres
Major
Muscle
Proximal Attachments
Distal Attachment
Innervation
Nerves:Lower Subscapular nerve.
Roots:(C5 & C6).
Main Actions
Adducts and
rotates arm.
medially
To Test the Muscle
To test the Teres major (or the lower
subscapular nerve that supplies it), the
abducted arm is adducted against
resistance.
If acting normally, the muscle can be
easily seen and palpated in the posterior
axillary fold.
Rotator
Cuff
Overview
They are Four of the Scapulohumeral muscles
(Supraspinatus, Infraspinatus, Teres minor, and
Subscapularis the SITS muscles).
They form a Musculotendinous rotator cuff around
the glenohumeral joint.
All except the Supraspinatus are rotators of the
Humerus; the supraspinatus, besides being part of
the rotator cuff, initiates and assists the deltoid in
the first 15° of abduction of the arm.
Rotator
Cuff
Rotator
Cuff
Supraspinatus
&
Infraspinatus
Muscle
Proximal Attachments
Distal Attachments
Innervation
Nerves:Suprascapular nerve.
Roots:Supra  (C4, C5 & C6).
Infra  (C5 & C6).
Main Actions
Supra  Initiates and assists
deltoid in abduction of arm
and acts with rotator cuff
muscles.
Infra  Laterally rotates arm;
and acts with rotator cuff.
To Test Supraspinatus
To test the supraspinatus,
abduction of the arm is
attempted from the fully
adducted position against
resistance.
To Test Infraspinatus
To test the Infraspinatus, the person flexes
the elbow and adducts the arm. The arm is
then laterally rotated against resistance.
If acting normally, the muscle can be
palpated inferior to the scapular spine.
To test the function of the Suprascapular
nerve, both muscles must be tested.
Teres
Miner
Muscle
Muscle Attachments
Innervation
Nerves:Axillary nerve.
Roots:(C5 & C6).
Main Actions
Laterally rotates arm;
and acts with rotator
cuff.
Subscapularis
Muscle
Distal Attachments
Innervation
Nerves:Upper and lower subscapular Nerves.
Roots:(C5, C6 & C7).
Main Actions
Medially rotates arm;
and acts with rotator cuff.
Helps hold head of
Humerus in glenoid cavity.
Thank you fighters