Upper Extremity 1 - PDF

UPPER EXTREMITY 1 SHOULDER COMPLEX ​ One of the most mobile segments in the human body ○​ Flexion, Abduction = 0-180 degrees ○​ ER = 0 -90 degrees ○​ IR = 0-70 degrees ○​ Shoulder complex is the only joint that can reach up to 180 degrees of mobility. ​ Scapulohu...

UPPER EXTREMITY 1 SHOULDER COMPLEX ​ One of the most mobile segments in the human body ○​ Flexion, Abduction = 0-180 degrees ○​ ER = 0 -90 degrees ○​ IR = 0-70 degrees ○​ Shoulder complex is the only joint that can reach up to 180 degrees of mobility. ​ Scapulohumeral Rhythm (GH:ST, 2:1) ​ Mobility of the shoulder complex is provided by 6 moving areas (joints in the shoulder complex): True Joints False Joints (+) Bone to bone articulation (-) bone to bone contact Aka Functional Joint SC Joint (Sternoclavicular Joint) Bicipital Groove AC Joint (Acromioclavicular Joint) Subacromial Joint GH Joint (Glenohumeral Joint) Scapulothoracic Joint Most important true joint that provides the The front of the scapula has muscle therefore greatest mobility at the shoulder complex. there is (-) direct bone contact. There is only sliding in respect to the posterior thoracic Synovial Ball and Socket Joint. wall. Ball and socket provides the greatest mobility among all of the joint types. Most important false joint. ○​ Remember to always assess all of these areas in order to properly know where the problem is. ​ Less static / structural stability ○​ Only connection of the SH complex to the axial skeleton is the SC Joint. ​ Good Dynamic Stability ○​ The muscles contract when the SH moves in order to maintain the humeral head in the glenoid fossa (Rotator Cuff Muscles : SITS) -> Supraspinatus, Subscapularis, Infraspinatus, Teres Minor OSSEOUS PARTS ​ Clavicle ○​ Long slender bone that lies horizontally at the root of the neck. ○​ S-shaped bone ○​ Orientation: ​ Middle ⅔ - convex anteriorly ​ Lateral ⅓ - concave anteriorly ​ Reverse when asked for the posterior orientation ○​ Most commonly fractured bone. MOI: ​ FOOSH - Fall On Outstretched Hand ​ FOS - Fall On Shoulder ​ Common in the geriatric population due to delayed reaction time. ​ Medially directed blow to the shoulder ​ Due to Newton’s 3rd law of motion when the px is falling. ​ Either px is dynamic or static when hit. Common in sports. ​ When fractured, muscle guarding will happen: ​ Medial Fragment - tilted superiorly by SCM (Sternocleidomastoid muscle) ​ Lateral Fragment - medially by Pectoralis Major, downward by gravity  ○​ Costoclavicular space ​ Between the clavicle and the first rib. ​ Where the subclavian artery and brachial plexus pass through. ​ Complete fx: Surgery. To save the structures that were hit by the fractured clavicle. ​ To test for complete fx, check the pulse of both arms, if one is weaker, then there is fracture. ​ Incomplete fx: Bandaging Techniques: Figure of 8 ​ Goal: shoulder retraction. To prevent a faulty shoulder in the px due to muscle guarding when the fx is healing. Also to decrease pressure in the clavicle. ​ Scapula ○​ Flat, triangular bone that lies on the posterior thoracic wall between the 2nd and 7th ribs. ​ Superior Angle: T2 (2nd rib) ​ Spine: T3 ​ Inferior Angle: T7 (7th rib) ○​ Acromion Process - summit of the shoulder ​ Orientation: Acromion PLS (Posterior, Lateral, Superior) ​ Types: (4) ​ Flat ​ Curved - most common type ​ Hooked - associated with impingement syndrome ○​ Painful arch: 60-120 degrees ○​ In this range, space narrows. When beyond, the humeral head slides inferiorly, creating space. ​ Upturned - least common type ○​ Coracoid Process ​ Orientation: Anterior and Superior ​ Coracoacromial ligament - prevents superior translation of the humerus. ○​ Spine of the Scapula ​ Extension of the acromion process medially. ​ Used to locate but not palpate structures above and below. ​ Suprasinous Fossa - above ​ Infraspinous Fossa - below ​ Subscapular Fossa - anterior to the spine of the scapula. Thus, the spine of the scapula is not used to locate this. ○​ Glenoid Fossa ​ Shallow cavity ​ (+) Glenoid Labrum - enhances the depth of the glenoid fossa by 50%. Also provides a suction effect on the humeral head. ​ Humerus ○​ Humeral Head ​ Forms ⅓ of a sphere ​ Intracapsular ​ Synovial ball and socket ○​ Anatomical Neck  ​ End attachment of the shoulder jt. Capsule. ○​ Surgical Neck ​ Below the greater and the lesser tuberosity, near the humeral shaft making it prone to fracture. ​ Axillary nerve - damaged when there is a surgical neck fracture. ​ Test Teres minor and Deltoids for possible weakness. Deltoids much more because T. minor is difficult to isolate. ​ Swallow Tail Sign- Sign for posterior deltoid weakness. Hyperextend both shoulders, if posterior Deltoid is weak, then the arms will be asymmetrical. ○​ Tuberosities ​ Greater Tuberosity is best viewed in ER (imaging) Location Palpation Ms attachment Greater Tub. Lateral IR SIT at the greater Lesser Tub. Medial ER Sub at the lesser ​ Q: Whenever px abducts, the lateral portion of the shoulder is hurting. What structure is affected? Greater Tuberosity. Because the G.T is lateral and rotator cuff muscles are: ​ Supraspinatus = abduction ​ Infraspinatus, Teres m. = ER ​ Subscapularis = IR ○​ Bicipital Groove ​ False Joint ​ Loc:between Greater and Lesser Tubercle ​ Aka Intertubercular Groove ​ Passageway for long head of the biceps (making the biceps a two jointed muscle) ​ Transverse humeral Ligament - keeps the long head of the biceps in bicipital groove. ​ Yergason’s Test - most common special test for suspected THL tears. ○​ Spiral Groove ​ Aka Radial Groove ​ Where the radial nerve (aka musculospiral nerve) passes through. ​ Loc: Posterior Shaft of the humerus ​ Site of fracture in the humerus ​ Radial Nerve Damage - damaged finger extensors, wrist extensors but Long Head of Triceps is spared, thus elbow extension is still intact. ○​ This is because the triceps is innervated by the radial nerve higher than the spiral groove because it also acts on the shoulder. TRUE JOINTS ​ Sternoclavicular Joint ○​ Only connection to the axial skeleton ○​ Type: Saddle / Sellar joint ○​ Articulation:Medial end of clavicle + manubrium ○​ Ligaments: ​ Interclavicular Ligament: Between 2 clavicles ​ Limits excessive depression of the distal end of the clavicle ​ Protects the subclavian and brachial plexus. ​ Costoclavicular Ligament: 1st rib and clavicle  ​ Limits excessive elevation of the distal end of the clavicle. ​ Sternoclavicular Ligament: sternum and clavicle ​ Anterior sternoclavicular ligament: Limits excessive retraction ​ Posterior sternoclavicular ligament: Limits excessive protraction ○​ Accessory Structure: Sternoclavicular Disc ​ Shock Absorption ​ Acts as hinge / pivot in UE motion ​ EDS - Elevation and depression, disc becomes part of sternum ​ PRC - Protraction and retraction, disc becomes part of the clavicle ○​ Kinematics: 3 degrees of freedom / 3 axes ​ Elevation and Depression ​ Protraction and Retraction ​ Long axial rotation / transverse rotation ​ Occurs primarily in one direction (posterior rotation). This occurs beyond 90 degrees of abduction. Anterior Rotation of the clavicle only happens when it returns to its resting position. ​ Elevation (< 90 deg) + Posterior Rotation (>90 deg)= Completely elevate the shoulder. ​ (-) posterior rotation, elevation is only up to 110 degrees. Because the other moving areas can compensate. ​ Acromioclavicular Joint ○​ Type: Synovial Plane Joint (slight gliding) ○​ Articulation: Acromion + Lateral end of clavicle ○​ Ligaments: ​ Acromioclavicular Ligament ​ Superior AC: prevents inferior translation of distal clavicle ○​ Thick Ligament, Primary ligament preventing inferior translation ​ Inferior AC: prevents superior translation of distal clavicle ○​ Thin ligament, not the primary ligament against superior translation ​ Coracoclavicular Ligament: Connects coracoid process and clavicle Conoid Ligament Trapezoid Ligament Triangle Quadrangular Medial Lateral Posterior Anterior Vertical fibers (provides vertical stability) Horizontal fibers (provides horizontal stability) Thick Ligament, primary ligament prevents Prevents medial displacement of scapula superior translation of distal clavicle ○​ Accessory Structure: Acromioclavicular Disc ​ Not as mobile as sternoclavicular disc ​ < 2 yrs old - fibrocartilaginous union (acromion process is fused with clavicle) ​ > 2 yrs old - Fibrocartilaginous remnant that is meniscoid (turns into AC disc) ○​ Kinematics: 3 degrees of freedom / 3 axes ​ Anterior and Posterior tilting - elevation and depression of the SC joint ​ IR and ER - protraction and retraction of SC joint ​ Upward and Downward rotation - posterior and anterior rotation of SC joint  ​ Posterior Tilting & Upward Rotation of the scapula for complete elevation of shoulder. ​ Glenohumeral Joint ○​ Type: Synovial Ball and Socket / Universal Joint. / Spheroidal Joint ○​ Articulation: ​ Humeral head (MPS): Medial, Posterior, Superior ​ Angle of Inclination - formed by the axis of humeral head and neck + axis of humeral shaft. ○​ N= 130 - 150 degrees ​ Angle of Torsion / Retrotorsion - formed by the axis of humeral head and neck + axis of humeral condyles. ○​ N= 30 degrees of retrotorsion ​ Glenoid Fossa (SAL): Superior, Anterior, Lateral ○​ Ligaments: ​ Coracohumeral Ligament: Coracoid to greater and lesser tuberosities. ​ Limits excessive ER + downwad translation of humerus. ​ Greatly involved in adhesive capsulitis / frozen shoulder (associated with Diabetes Mellitus). CH ligament thickens and tightens, turning the humerus in IR position. ER > ABD > IR (minimal).This is the capsular pattern of SH. ​ Glenohumeral Ligament: ​ Limits excessive ER at different angles ○​ Superior fibers - 0-45 degrees ○​ Middle fibers - 45 - 90 degrees ○​ Inferior fibers - >90 degrees ​ Rockwood test - ER at different angles ​ Most common direction of SH dislocation: Anteroinferior. Weak Spots: ​ Foramen of Weitbrecht - between superior and middle ​ Foramen of Rouvier- between middle and inferior ​ Contraindicated motion: ABD and ER / D2 flexion ○​ Accessory Structures: Glenoid Labrum - enhances the depth of the fossa by 50% ○​ Kinematics: 3 degrees of freedom , 3 axes / multiaxial joint ​ Flexion and Extension ​ Abduction and Adduction ​ ER and IR FALSE JOINT ​ Bicipital Groove ○​ Medial: Me-Ter (Teres Major) = ExAdIR ○​ Lateral: Pec-Lat (Pectoralis Major) ○​ Floor: FLats (Latissimus Dorsi) = ExAdIR ○​ Roof: Transverse Humeral Ligament (THL) ​ Subacromial Joint ○​ Aka Suprahumeral Joint / Supraspinatus Outlet ○​ Supraspinatus Muscle: Most vulnerable structure that pass through the subacromial joint ○​ Acromiohumeral Interval - distance between the Acromion process and the humerus ​ Arms at side: 10 mm ​ Elevated: 5 mm  ○​ Subacromial Bursa - prevents direct contact of supraspinatus and acromion process. ​ Scapulothoracic joint ○​ Scapulohumeral Rhythm: after 30 degrees of abduction, a 2 (GH) : 1 (ST) ratio occurs ○​ 180 degree full rotation: 120 degree for GH, 60 degree for ST. ○​ Phases of Scapulohumeral Rhythm Humerus (GH jt) Scapula (AC jt) Clavicle (ST jt) (post rot) Phase I 30 degrees Setting phase Elevation Phase II (90 deg) 40 degrees 20 degrees Elevation Phase III (>90) 60 degrees 30 degrees Posterior Rotation STATIC / STRUCTURAL STABILITY ​ Negative intra articular pressure ○​ Due to the glenoid labrum causing vacuum/suction effect. ​ Upward tilt of the glenoid fossa provides a bony block against inferior translation. ​ Passive tension from ligaments DYNAMIC STABILITY ​ Terms: ○​ Force Couple ​ 2 opposing forces that result to rotation ○​ Positive Translatory Force ​ Upward direction ○​ Negative Translatory Force ​ Downward direction ​ Deltoids and GH joint Stabilization ○​ deltoids alone cannot abduct the shoulder ​ Large translatory force (upward) ​ Small rotary force of the deltoids (abduction) ​ Rotator Cuff and GH joint Stabilization ○​ ITS muscle: provides negative translatory force ​ SupraSpinatus and GH joint Stabilization ○​ Small positive translatory force ○​ Countered by gravity giving downward force, canceling the upward motion allowing abduction. ​ NOTE: All of these contract while maintaining the humeral head inside the Glenoid Fossa. LANDMARKS ​ Walls of the Axilla ○​ Anterior: PecPecSub ​ Pec min., maj., Subclavius ○​ Posterior: SuLaTeMa ​ Subscapularis, Latissimus Dorsi, Teres Major ○​ Lateral: BiBiCo ​ Biceps in Bicipital Groove, Coracobrachialis ○​ Medial: Ribs 2-6 + Serratus Anterior  Spaces Superior Inferior Medial Lateral Contents Quadrangular Space Teres Minor Teres Major Long Head Humerus Axillary Nerve Triceps Posterior Circumflex Humeral Artery Triangular Space Teres Minor Teres Major X Long Head Circumflex Scapular Triceps Artery BRACHIAL PLEXUS ​ Anterior / Ventral Rami of C5 - T1 (RoTunDaCuBao) ​ 16 branches ​ Roots: ○​ Dorsal Scapular Nerve: Rhomboids and Levator Scapulae ○​ Long Thoracic Nerve: Serratus Anterior ​ Trunks ○​ Nerve to subclavius: Subclavius ○​ Suprascapular Nerve: Supraspinatus and Infraspinatus ​ Divisions ​ Cords ○​ Lateral Pectoral Nerve: Pectoralis Major ○​ Upper subscapular Nerve: ○​ Middle Subscapular Nerve / Thoracodorsal Nerve: Latissimus Dorsi ○​ Lower Subscapular Nerve ○​ Medial Pectoral Nerve: Pectoralis Major and Minor ○​ Medial Cutaneous Nerve of the Arm ○​ Medial cutaneous Nerve of the Forearm ​ Branches ○​ Musculocutaneous Nerve: lateral cord (C5, C6, C7) ○​ Axillary Nerve: posterior cord (C5, C6) ○​ Radial Nerve: posterior cord (Largest Branch = C5-T1) ○​ Ulnar nerve: medial cord (C8 - T1) ○​ Median Nerve: Lateral and Medial cord (C5 - T1 / C6 - T1)