191B KIN Advanced Assessment of Upper Extremity Injuries
Shoulder Anatomy and Evaluation
Anatomy
Anatomy
Bony anatomy Articulations and ligamentous anatomy Muscular anatomy Neurological and vascular anatomy Bursae of the shoulder
Bony Anatomy
Bony Anatomy
Sternum Clavicle Humerus Scapula
Sternum
Manubrium attachment site for clavicle
Jugular notch
Body Xiphoid process
Sternum
Clavicle
Humerus
Head and neck Greater tuberosity Lesser tuberosity Bicipital (intertubercular) groove Long head of biceps tendon Deltoid tuberosity Angle of inclination Shaft of humerus and head of humerus in frontal plane (normally 130-150 degrees) Angle of torsion Shaft of humerus and head of humerus in transverse plane (significant variance amongst individuals)
Humerus
Scapula
Vertebral (medial), axillary (lateral) and superior border Inferior and superior angles Glenoid, subscapular, supraspinous and infraspinous fossas Scapular spine Acromion process Coracoid process
Scapula
Plane of the Scapula
In anatomic position, glenoid angles 30 degrees from frontal plane this is the plane of the scapula More functional arc of motion than cardinal planes and places rotator cuff muscles in optimal length-tension relationship
Articulations and Ligamentous Anatomy
Articulations
Sternoclavicular (SC) joint Acromioclavicular (AC) joint Glenohumeral (GH) joint Scapulothoracic articulation
Sternoclavicular Joint
Proximal clavicle and manubrium Anterior and posterior SC ligaments Resist anterior and posterior displacement of proximal clavicle Costoclavicular ligament Inferior proximal clavicle and rib 1 axis of movement for clavicle (elevation, depression, medial, lateral) Interclavicular ligament Connects both SC joints Fibrocartilaginous SC disc Functions similar to meniscus of knee, axis of rotation for clavicle
Sternoclavicular Joint
Acromioclavicular Joint
Distal clavicle and acromion process Superior and inferior AC ligaments Coracoclavicular ligament provides most intrinsic stability to AC joint
Conoid portion medial, triangular
Restricts superior clavicular motion
Trapezoid portion lateral, quadrilateral
Restricts lateral movement of distal clavicle over acromion process
Acromioclavicular Joint
Glenohumeral Joint
Glenohumeral ligaments (joint capsule)
Superior, middle and inferior GH ligaments are thickenings of joint capsule
Coracohumeral ligament
Blends with superior joint capsule from coracoid process
Coracoacromial arch/ligament
Connects 2 prominences of the same bone, often involved in impingement syndromes/conditions
Glenoid labrum deepens ball and socket
Glenohumeral Joint
Glenoid Labrum
Scapulothoracic Articulation
Not a synovial joint no bony articulation Articulation via muscular attachments
Muscular Anatomy
Muscular Anatomy
Muscles acting on the scapula
Rhomboid major/minor Levator scapulae Serratus anterior Pectoralis minor/major Trapezius Latissimus dorsi
Responsible for
Moving glenoid to allow for increased shoulder ROM Fixation of scapula on thorax to provide rotator cuff muscles base of support during contractions
Rhomboids
O: major T2-5 spinous processes, minor C7, T1 spinous processes I: vertebral (medial) border of scapula N: dorsal scapular A: scapular retraction, elevation, downward rotation
Levator Scapulae
O: C1-4 transverse processes I: superior angle of scapula N: dorsal scapular A: scapular elevation, downward rotation
Serratus Anterior
O: anterior portion of ribs 1-8 I: vertebral (medial) border of scapula from superior angle to inferior angle N: long thoracic A: scapular protraction and upward rotation, fixates vertebral border of scapula to thorax
Pectoralis Major
O: clavicular head medial half of clavicle, sternal head lateral portion of sternum I: greater tuberosity of humerus (lateral lip of bicipital groove) N: medial and lateral pectoral A: sternal head shoulder depression and horizontal adduction, clavicular head flexion, internal rotation and horizontal adduction
Pectoralis Minor
O: anterior portion of ribs 3-5 I: coracoid process N: lateral pectoral A: anterior tilt of scapula
Trapezius
Upper fibers
Base of occiput/upper cervical spinous processes to distal clavicle, elevate and upwardly rotate scapula
Middle fibers
Lower cervical/upper thoracic spinous processes to acromion process, retract scapula
Lower fibers
Lower thoracic spinous processes to spine of scapula, depress and upwardly rotate scapula
N: accessory nerve (CN XI)
Latissimus Dorsi
O: T6-12 spinous processes, thoracolumbar fascia, iliac crest I: intertubercular (bicipital) groove N: thoracodorsal (middle subscapular) A: adduction, internal rotation, extension
Muscular Anatomy
Muscles acting on the humerus
Rotator cuff (SITS)
Supraspinatus, infraspinatus, teres minor, subscapularis
Deltoid Pectoralis major Latissimus dorsi Teres major Long head of triceps Biceps, short/long head Coracobrachialis
Supraspinatus
O: supraspinous fossa I: greater tuberosity N: suprascapular A: abducts and externally rotates humerus
Infraspinatus
O: infraspinous fossa I: greater tuberosity N: suprascapular A: externally rotates humerus
Teres Minor
O: axillary (lateral) border of scapula I: greater tuberosity N: axillary A: externally rotates humerus
Subscapularis
O: subscapular fossa I: lesser tuberosity N: upper and lower subscapular A: internally rotates humerus
Deltoid
Anterior fibers distal clavicle, shoulder flexion, horizontal adduction and internal rotation Middle fibers acromion process Posterior fibers spine of scapula, shoulder extension, horizontal abduction and external rotation I: deltoid tuberosity N: axillary A: shoulder abduction
Teres Major
O: inferior angle of scapula, axillary (lateral) border of scapula I: medial lip of bicipital groove N: lower subscapular A: internal rotation, adduction, extension
Triceps Brachii
Long head inferior glenoid rim/tuberosity Lateral head lateral and posterior proximal humerus Medial head medial distal humerus I: olecranon process N: radial A: extends elbow, long head adducts and extends humerus
Biceps Brachii
Long head superior glenoid rim/tuberosity Short head coracoid process I: radial tuberosity N: musculocutaneous A: elbow and shoulder flexion
Transverse Humeral Ligament
Bridges bicipital groove from greater to lesser tuberosity Stabilizes long head of biceps tendon in groove
Coracobrachialis
O: coracoid proces I: medial humeral shaft N: musculocutaneous A: flexion and adduction
Neurovascular Anatomy
Neurovascular Anatomy
Neurological anatomy
Brachial plexus review
Vascular anatomy
Subclavian artery becomes axillary artery as it passes first rib, which becomes brachial artery as it passes distal to teres major
Brachial Plexus
Vascular Supply
Bursae
Subacromial bursa Sits superior to rotator cuff tendons in subacromial space Reduces friction from movement of overlying deltoid Provides protection against inferior surface of acromion process
Shoulder Biomechanics
Rotator Cuff Muscle Activity
During shoulder (GH) abduction:
At ~70 degrees, humeral head depressed by infraspinatus, minor teres and subscapularis to allow humeral head to clear acromion process At ~115 degrees, humeral head externally rotated by infraspinatus and teres minor to clear greater tuberosity of humerus under acromial arch
Scapulothoracic Rhythym
During first 30 degrees of GH abduction, scapular is setting may have slight upward rotation From 30-180 degrees, for every 2 degrees of GH motion is 1 degree of scapular motion (rotation) During first 90 degrees, scapula rotates with SC joint as pivot point During last 90 degrees, scapula rotates with AC joint as pivot point
Conoid portion of coracoclavicular ligament becomes taut and produces posterior rotation of clavicle allowing for more AC and scapular motion
Evaluation of Shoulder Injuries
History
History
Location of pain Onset of symptoms Mechanism of injury (etiology) Current symptoms History of previous injury
Location of Pain
Localized pain in shoulder typically associated with localized injury Pain radiating proximally and/or distally increases likelihood of neurological involvement
Onset of Symptoms
Acute onset
Fracture, GH subluxation or dislocation, AC sprain
Chronic/insidious onset
Inflammatory conditions (tendonitis, bursitis) Pain after activity first, then during, and finally at all times
Mechanism of Injury
Direct trauma or forces
Acute soft tissue and/or bony injury
Repetitive overhead movements (throwing, swimming, tennis)
Overuse syndromes, inflammatory conditions, impingement syndromes
Current Symptoms
Unusual sounds or sensations Quantity and quality of pain, aggravating and alleviating factors Radiating pain neurological involvement Dysfunction and/or decreased performance
History of Previous Injury
Previous cervical spine injury can predispose individual to shoulder injury from neurological compromise (weakness) Prior AC or GH injury can affect shoulder biomechanics and thereby increase the risk of overuse conditions/muscle imbalances
Inspection
Inspection
General postural assessment Anterior structures Lateral structures Posterior structures
General Postural Assessment
Head
Lateral flexion or rotation may indicate muscle spasm and/or cervical nerve root injury
Upper extremity
Splinted to side of body/rib cage Forearm supported limp arm from brachial plexus injury Deformity from GH dislocation
Anterior Structures
Level of shoulders
AC joints, SC joints, clavicle
Clavicular contour
Displacement with joint injury or fracture
Deltoid contour symmetry
Normally rounded, may be flattened secondary to GH dislocation or axillary nerve injury
Biceps brachii symmetry
Bulges from biceps tendon rupture
Lateral Structures
Deltoid contour (as before) Acromion process
step off deformity at AC joint (piano key)
Humeral position
Anterior or posterior displacement with dislocation
Posterior Structures
Vertebral alignment - scoliosis Scapular position symmetry
Superior angle at T2 spinous process, inferior angle at T7 spinous process winging scapula
Muscle tone
Increased tone secondary to spasm/injury Decreased tone (atrophy) secondary to neurological compromise or disuse
Humeral position (as before)
Palpation
Palpation Anterior Structures
Jugular notch SC joint Clavicle Acromion process AC joint Coracoid process Humeral head Greater tuberosity Lesser tuberosity Bicipital groove Humeral shaft Pectoralis major Coracobrachialis Deltoid Biceps brachii
Palpation Posterior Structures
Spine of scapula Superior angle Inferior angle Rotator cuff
Subscapularis Supraspinatus Infraspinatus Teres minor
Teres major Rhomboids Levator scapulae Trapezius Latissimus dorsi Posterior deltoid Triceps brachii
Special Tests
Special Tests
Range of motion testing
Active, passive and resistive ROM Combination movements
Neurological evaluation Vascular evaluation Ligamentous/capsular testing
Active Ranges of Motion
Flexion 180 degrees
Biceps brachii, coracobrachialis, anterior and middle deltoid, pectoralis major (clavicular head)
Extension 60 degrees
Posterior deltoid, latissimus dorsi, teres major, triceps brachii (long head)
Active Ranges of Motion
Abduction 180 degrees
Deltoid, supraspinatus, biceps brachii
Adduction - ~45 degrees if shoulder flexed slightly to avoid body interference
Pectoralis major, latissimus dorsi, teres major, coracobrachialis, triceps brachii
Active Ranges of Motion
Internal rotation limited by body in neutral position, 70-80 degrees at 90/90
Subscapularis, pectoralis major, latissimus dorsi, teres major, anterior deltoid
External rotation 40-50 degrees in neutral position, 80-90 degrees at 90/90
Infraspinatus, teres minor, supraspinatus, posterior deltoid
Active Ranges of Motion
Horizontal abduction 45 degrees from plane of scapula at 90 degrees abduction
Posterior deltoid, infraspinatus, teres minor
Horizontal adduction 120 degrees from plane of scapula at 90 degrees abduction
Pectoralis major, anterior deltoid
Active Ranges of Motion
Scapular protraction
Serratus anterior, pectoralis minor
Scapular retraction
Trapezius, rhomboids, levator scapulae
Scapular elevation
Upper trapezius, levator scapulae, rhomboids
Scapular depression
Lower trapezius, pectoralis minor, subclavius
Scapular downward rotation
Rhomboids, pectoralis minor
Scapular upward rotation
Trapezius, serratus anterior
Scapular Ranges of Motion
Apleys Scratch Tests
Touch opposite shoulder in front
Adduction, horizontal adduction, internal rotation, scapular protraction
Touch opposite shoulder in back
Abduction, external rotation, scapular protraction, elevation and upward rotation
Touch opposite scapula from behind
Adduction, internal rotation, scapular retraction and downward rotation
Passive Ranges of Motion
Critical to stabilize proximal segment in order to accurately assess end feel patient positioning Flexion and extension firm end feel Abduction firm end feel (GH and total) Adduction not typically assessed ER/IR firm end feels Horizontal abduction/adduction firm end feels unless soft tissue obstructs adduction
Resisted Ranges of Motion
Must stabilize proximal segment to isolate movement and/or muscle/s Graded on 0-5 scale keep in mind effects of gravity, especially in presence of significant weakness
Gerber Lift-Off Test
Humerus internally rotated and dorsal aspect of hand placed against back Positive test for subscapularis weakness if unable to lift hand off spine
Scapular Winging
Perform push-up against wall Positive test for serratus anterior weakness and/or long thoracic nerve injury if vertebral (medial) border of scapula lifts off thorax
Neurological Evaluation
Brachial plexus dermatomes and myotomes Sensory and motor tests for terminal branches of brachial plexus
Axillary, radial, median, ulnar, musculocutaneous
Awareness of innervation of muscles acting on scapula and humerus
Vascular Evaluation
Axillary pulse can sometimes be palpable in axilla Brachial pulse felt along medial shaft of humerus or in cubital fossa near biceps tendon Radial pulse is most common evaluation site
Ligamentous/Capsular Testing
To be discussed in detail with specific shoulder pathologies