Back & Scapular Region PDF

Dr Vandana Dave Assistant Professor Department of Anatomy Amrita School of Medicine, Faridabad  Learning Objectives By the end of this teaching session all the students should be able to: List the back muscles of each group Distinguish between the different grou...

Dr Vandana Dave Assistant Professor Department of Anatomy Amrita School of Medicine, Faridabad  Learning Objectives By the end of this teaching session all the students should be able to: List the back muscles of each group Distinguish between the different groups of back muscles connecting appendicular skeleton to axial skeleton Describe the attachments, nerve supply and action muscle of trapezius, rhomboideus, levator scapulae and latissimus dorsi Describe the triangles of back and their clinical significance Competencies By the end of this teaching session all the students should be able to: AN10.8 Describe, identify and demonstrate the position, attachment, nerve supply and actions of trapezius and latissimus dorsi Surface landmarks Surface landmarks Lumbar puncture Cutaneous nerves Upto T6 – Medial division of posterior primary rami of spinal nerves, emerge close to median plane Below T6 – Lateral division of posterior primary rami of spinal nerves, emerge at lateral border of erector spinae Cutaneous arteries – accompany cuta. nerves, in thoracic region: dorsal br. of posterior intercostal arteries, in lumbar region: dorsal br. of lumbar arteries No cutaneous branch arise from the posterior rami of C1,C7,C8,L4 and L5 spinal nerves Muscles of back Superficial layer – consists of muscles involved in movements of upper limb, innervated by anterior rami of spinal nerves Intermediate layer - consists of muscles attached to the ribs Deep layer – consists of the intrinsic muscles of back, innervated by posterior rami of spinal nerves, support and move the vertebral column and head  Muscles of back Superficial layer (5M) – trapezius, latissimus dorsi, rhomboid major, rhomboid minor and levator scapulae  Muscles of back Intermediate layer (2M)– serratus posterior superior, serratus posterior inferior, innervated by anterior rami of T2 to T5 and T9 to T12 thoracic nerves respectively  Muscles of back Deep layer – splenius capitis, splenius cervicis erector spinae (consists of spinalis, longissimus, iliocostalis) transversospinales (consists of semispinalis, multifidus, rotatores) interspinales and intertransversarii  Muscles of back Deep layer – splenius capitis, splenius cervicis erector spinae (consists of spinalis, longissimus, iliocostalis) transversospinales (consists of semispinalis, multifidus, rotatores) interspinales and intertransversarii Muscles of back Trapezius Latissimus dorsi Levator scapulae Rhomboid minor Rhomboid major Structures under cover of trapezius Spines of T7-T12 vert, TL fascia, Iliac crest, Lower 3-4 ribs, Inferior angle of scapula  (C5) (C5) (C5)  Levator scapulae Dorsal scapular nerve Dorsal scapular nerve or n to rhomboideus Superficial branch of transverse cervical artery Arise from C5 root Trapezius piercing Scalenus medius Accompany deep Rhomboid branch of tran minor cervical artery Rhomboid major Deep branch of transverse cervical artery Latissimus dorsi  Musculocutaneous flap of Cardiomyoplasty latissimus dorsi LD with its intact neurovascular Thoracodorsal nerve, bundle can be used as an thoracodorsal artery and autotransplant to repair the portion of thoracodorsal vein are cardiac muscle collectively known as Pacemaker is implanted in the thoracodorsal pedicle (TDP), detached portion of LD to provide runs on post. Wall of axilla continuous rhythmic contraction Enter LD at single neurovascular hilum 3-4 cm med. to its lat. border Often used in reconstruction surgery of breast following mastectomy  Floor – 6th and 7th rib, 6th IC space Upper part of lower lobe of lung lies deep to the triangle  Floor – fascia transversalis Floor – Internal oblique  Scapular region AN10.9 Describe the arterial anastomosis around the scapula and mention the boundaries of triangle of auscultation AN10.10 Describe and identify the deltoid and rotator cuff muscles AN10.13 Explain anatomical basis of Injury to axillary nerve during intramuscular injections Scapulohumeral muscles Deltoid Supraspinatus Infraspinatus Teres minor Teres major Subscapularis Deltoid Ant part and post part – unipennate, middle (acromial) part - multipinnate Origin Lateral third of clavicle, acromion, spine of scapula Insertion Deltoid tuberosity of humerus Nerve supply Axillary nerve C5, 6 Action Anterior fibers- flexion and medial rotation of arm Middle fibers- Abduction (15-90 degrees) Posteror fibers-extention and lateral rotation of arm Axillary nerve and posterior circumflex humeral vessels lies deep to the upper part of deltoid.  Structures under cover of Deltoid BONE- Upper part humerus, coracoid process, greater tubercle, lesser tubercle Intertubercular sulcus Bursa- Subdeltoid , subacromial bursa Muscles – attached around shoulder joint Vessel- Ant and Post circumflex humeral vessel Nerves- Axillary nerve Scapular spaces – quadrangular and triangular space Structures under cover of Deltoid A B Supraspinatus Origin Medial 2/3rd of Supraspinous fossa, superior surface of spine of scapula Insertion Upper impression of Greater tubercle of humerus Nerve supply Suprascapular nerve (C5,6) Action Initiation of abduction (0-15 degrees) of arm Infraspinatus Origin Medial 2/3rd of Infraspinous fossa, inferior surface of spine of scapula Insertion Middle impression of greater tubercle of humerus Nerve supply Suprascapular nerve (C5,6) Action Lateral rotation of arm Suprascapular nerve Teres major Origin Lower third of dorsal aspect of lateral border and inferior angle of scapula Insertion Medial lip of bicipital groove of humerus Nerve supply Lower subscapular nerve (C5,6) Action Adduction and medial rotation of arm and stabilizes shoulder joint Teres minor Origin Upper two thirds of lateral border of scapula Insertion Lower impression of greater tubercle of humerus Teres minor Nerve supply Axillary nerve (C5,6) Action Lateral rotation of arm Subscapularis Origin Medial 2/3rd of Subscapular fossa Insertion Lesser tubercle of humerus Nerve supply Upper (C5,6) and lower subscapular nerves (C5,6) Action Adduction, medial rotation of arm Rotator Cuff The tendons of the subscapularis, supraspinatus, infraspinatus, and teres minor muscles are fused to the underlying capsule of the shoulder joint Stabilizing the shoulder joint The cuff is deficient inferiorly, and this is a site of potential weakness. Rotator Cuff Intermuscular spaces Dr Vandana Dave  Axillary Nerve The axillary nerve arises from the posterior cord of the brachial plexus (C5, 6) in the axilla It passes backward and enters the quadrangular space with the posterior circumflex humeral artery As the nerve passes through the space, it comes into close relationship with the inferior aspect of the capsule of the shoulder joint and with the medial side of the surgical neck of the humerus It terminates by dividing into anterior and posterior branches  Axillary Nerve Branches: 1. Articular branch 2. Anterior branch, which winds around the surgical neck of the humerus accompanies posterior circumflex humeral vessels, supplies deltoid and skin anteroinferior part of deltoid 3. Posterior branch winds around posterior border of deltoid, gives off a branch to the teres minor muscle (nerve to teres minor bears a pseudoganglion) and a few branches to the deltoid, then emerges from the posterior border of the deltoid as the upper lateral cutaneous nerve of the arm Causes: fracture of neck of humerus, dislocation of shoulder joint, intramuscular injection in upper part of Sensory loss over deltoid lower part of Deltoid Sign and symptoms: loss of abduction (15-90) due to paralysis of deltoid Regimental badge anaesthesia Loss of rounded contour of shoulder Regimental badge anaesthesia  Anastomosis around scapula Acromial br of Thyrocervical trunk Transvers cervical artery Suprascapular artery thoracoacromial Deep br of Thoracoacromial artery Suprascapular artery artery transverse cervical artery Posterior Acromial br of circumflex suprascapular humeral artery Acromial br artery of posterior circumflex Circumflex humeral scapular artery Circumflex artery scapular artery Deep br of Subscapular artery transverse Anastomosis over cervical Anastomosis acromion process artery around Scapula Branches of subclavian artery Branches of axillary artery Include different shoulder conditions: Supraspinatus Thickening of supraspinatus tendon syndrome by calcification or other degenerative Subacromial bursitis changes Long head of biceps tendon pain Can be caught underneath the Acromioclavicular acromion joint arthritis Impinging upon supraspinatus tendon, when arm is abducted Pain (600 to 1200 of abduction)  It is an insidious and painful condition of unknown etiology Causes fibrosis of glenohumeral joint capsule with progressive stiffness and restricted range of motion Self-limiting, Symptoms usually resolve with time and exercise, or steroid injections. ❑ caused by trauma to the shoulder or "wear and tear" of tendons ❑Partial or complete tear ❑Seen more in athletes due to repetitive overhead abduction