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SCAPULAR REGION

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SCAPULAR REGION Powered By Docstoc
					               Anatomy of the Upper Limb
              Muscles of the Back & Scapular Region
                Trapezius                                    Axillary Nerve

                                   Deltoid
                   Infraspinatus



                                                            Biceps




Teres Major
                                                                              Subscapularis



                                                      Teres Major

                                                       Latissimus Dorsi
                                   Latissimus Dorsi


                 By: Dr. YOUSSEF SHOUKRY
                                                    ANATOMY OF THE UPPER LIMB … BY: Dr. YOUSSEF SHOUKRY

                                                       MUSCLES OF THE BACK OF THE SHOULDER GIRDLE
      Muscle Name                                     Origin                     Insertion                      Action                                                                    Nerve Supply
1.   Trapizius (‫)ترابيس‬                      External        occipital In V shape insertion of:     Upper         fibers                                                         The only muscle that is
                                              protuberance               Clavicle (lateral 1/3)        elevation        of the                                                     not supplied by the
                                             External occipital crest  Acromion           (Medial     shoulder (Shrugging of                                                      brachial    plexus  
                                             Ligamentum Nuchae            aspect)                      the shoulder)                                                               supplied by the spinal
                                             Supraspinous ligament      Spine (Upper border)       Lower fibers  upward                                                         accessory nerve
                                             T1-T12 spine                                              rotation of the scapula
                                                                                                        (Abduction > 90°)
2.   latissimus               Dorsi          T6-T12 spine under        By a very thin white  Extension                                                                            Nerve to latissimus dorsi
     (‫)المجانص‬                                cover of the Trapizius tendon into the floor of the  Adduction                                                                       (From the posterior cord of
                                              muscle                    bicepital groove             Medial rotation                                                               the brachial plexus)
                                             Lumbar fascia                                         … of the arm
                                             Iliac crest                                            Scratching muscle
                                             Lower 4 ribs                                           Wearing a jacket
                                             Lower angle of the                                    Note: it passes from the
                                              scapula                                               back to the front with
                                                                                                    triple relation with the
                                                                                                    teres major muscle:-
                                                                                                    1st : Behind it
                                                                                                    2nd : Below it
                                                                                                    3rd : In front of it
3.   Levator Scapulae                        Transverse process of  Upper 1/3 of the medial  Levator : elevation of                                                              Nerve to rhomboids from
                                              C1-C4                        border of the scapula        the scapula                                                                 the roots of the brachial
4.   Rhomboids Minor                         Spine of C7-T2             At the medial border of  Both          rhomboids   :                                                     plexus
                                                                           the scapula opposite to      downward rotation of
5.   Rhomboids Major                         Spine of T2-T5               the spine                    the scapula
                                                                         Lower 2/3 of the medial  The 3 muscles together
                                                                           border of the scapula        : retraction of the
                                                                                                        scapula




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                                               ‫‪ANATOMY OF THE UPPER LIMB … BY: Dr. YOUSSEF SHOUKRY‬‬




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                                                   ANATOMY OF THE UPPER LIMB … BY: Dr. YOUSSEF SHOUKRY

                                                       MUSCLES OF THE SCAPULAR REGION
   Muscle Name                                   Origin                  Insertion               Action                                                                                Nerve Supply
6. Supraspinatus                         Medial       2/3      of Upper facet over the Abduction from 0° -                                                                         Supra scapular nerve
                                         supraspinus fossa        greater tuberosity of 18° of the shoulder
                                                                  the humerus           joint
7. Infraspinatus                         Medial       2/3      of Middle facet over the Extension & lateral                                                                        Supra scapular nerve
                                         infraspinus fossa        greater tuberosity of rotation     of the
                                                                  the humerus           shoulder joint
8. subscapularis                         Medial       2/3      of Lesser tuberosity     Flexion & medial                                                                           Upper     &      lower
                                         subscapular fossa                              rotation     of the                                                                        subscapular nerves
                                                                                        shoulder joint
9. Teres Major                           Lower 1/3 of the Medial lip of the Extension & medial                                                                                     Lower                subscapular
                                         lateral border of the bicepital groove         rotation     of the                                                                        nerve
                                         scapula                                        shoulder joint
10. Teres Minor                          Upper 2/3 of the lateral Lower facet over the Extension & lateral                                         Axillary nerve (C5,
                                         border of the scapula greater tuberosity of rotation        of the                                        C6) from the posterior
                                         above teres major        the humerus           shoulder joint                                             cord of the brachial
                                                                                                                                                   plexus
11. Deltoid                              Anterior, middle & V-shaped                                                 deltoid  Anterior fibers  Axillary nerve (C5,
                                         posterior fibers have a tuberosity                                                    flexion & medial C6)
                                         V shaped origin from :                                                                rotation
                                          Clavicle                                                                           Middle fibers 
                                          Acromion                                                                            abduction upto 90°
                                          Spine                                                                              Posterior fibers 
                                         trapizius ‫عكس ال‬                                                                      extension & lateral
                                                                                                                               rotation



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                                               ‫‪ANATOMY OF THE UPPER LIMB … BY: Dr. YOUSSEF SHOUKRY‬‬




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                                                   ANATOMY OF THE UPPER LIMB … BY: Dr. YOUSSEF SHOUKRY


                                                                                         Axillary Spaces
1. The quadrangular space :
  Boundaries : teres major muscle, teres minor muscle, the
  long head of the triceps muscle and the humerus.
  Contents : axillary nerve & the posterior circumflex humeral
  artery.


2. The upper triangular space :
  Boundaries : teres major muscle, teres minor muscle and the
  long head of the triceps muscle.
  Contents : the circumflex scapular artery.


3. The lower triangular space :
  Boundaries : teres major muscle, long head of the triceps
  muscle and the humerus.
  Contents : radial nerve and the profunda brachii artery.
N.B.: the subscapularis muscle can replace the teres major
muscle in the anterior view of the spaces.


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                 ANATOMY OF THE UPPER LIMB … BY: Dr. YOUSSEF SHOUKRY

                                                 The Axillary nerve
    Root value : C5, 6.
    Beginning : as a branch of the posterior cord of the brachial plexus.
    Course and relations : the nerve begins poaterior to the 3rd part of the
      axillary artery then it is directed laterally with the posterior circumflex
      humeral artery to enter the quadrangular space of the axilla and then they pass
      posterior to the surgical neck of the huemrus (Dangerous site), then the nerve
      divides into anterior and posterior divisions.
    Distribution :
   1. Motor : deltoid and teres minor muscles.
   2. Sensory : to the skin over the deltoid by its upper lateral cutaneous branch &
      sensory to the shoulder joint.
    Effect of lesion :
   Motor loss  loss of abduction (18 - 90°) atrophy of the deltoid leading to flat
   shoulder.
   Sensory loss  loss of sensations from the skin over the deltoid muscle.




Axillary       Nerve
(Posterior View)
                                                                                                                    Axillary      Nerve
                                                                                                                    (Anterior View)



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             ANATOMY OF THE UPPER LIMB … BY: Dr. YOUSSEF SHOUKRY

                                            The Shoulder Joint
 Articulating bones : head of the humerus, the glenoid cavity that is widen by
  the labrum glenoidale.
 Type : synovial ball and socket joint, multi-axial joint.
 Movement : being a multi-axial, joint the shoulder joint can permit 6 types of
  movement, which are :
1. Flexion.                                    3. Adduction.                                   5. Medial rotation.
2. Extension.                                  4. Abduction.                                   6. Lateral rotation.
 Muscles producing movement :
1. Muscles attached with origin and insertion from front of the joint (Pectoralis
  major & subscapularis)  flexion and medial rotation.
2. Muscles attached with origin and insertion from behind the joint (Teres minor
  & infraspinatus)  extension and lateral rotation.
3. Muscles attached with origin from behind the joint and is inserted to the front
  (Latissimus dorsi & teres major)  extension and medial rotation =wearing
  jacket.
4. All the muscles that are originating from the chest wall (Pectoralis major) or
  scapula can produce adduction (i.e. all the previous muscles).
5. Abduction :                 - 0 – 18°  produced by the supraspinatous muscle.
                               - 18 – 90°  produced by the deltoid muscle (Middle fibers).
                               - > 90°  produced by the trapizius & serratus anterior
                               muscles (Lower fibers of both muscles).


In abduction, rotation of the scapula must occur
For each 5° movement of the humerus  1° rotation of the scapula.
Oral question: Can abduction of the shoulder joint >90° occur without
rotation of the scapula?




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             ANATOMY OF THE UPPER LIMB … BY: Dr. YOUSSEF SHOUKRY

In the shoulder joint, the movement is increased on the expense of the stability,
and the factors that weakens the joint and those that stabilize it are :
         Weakening Factors                          Stabilizing Factors
1. Large head of the humerus.            1. Glenoid labrum.
                                         2. Capsular ligament (Extra-capsular).
                                         Gleno-humeral ligament.
2. Small glenoid cavity.
                                         Coraco-humeral ligament.
                                         Coraco-acromial ligament.
3. Lax capsule.                          3. Rotator cuff muscles.
4. No intra-articular ligaments (i.e. no 4. 2 long heads  long triceps & long
   intra-capsular ligaments).               biceps.

Dislocation is common in the shoulder joint (By downward traction) which may
lead to injury of the axillary nerve.




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