Download tear of rotator cuff

Structure of shoulder
 Most complex joint in human body
 Include 5 different articulations
1) Glenohumeral joint
2) Strenoclavicular joint
3) Acromioclavicular joint
4) Coracoclavicular joint
5) Scapulothoracic joint
1.Sternoclavicular joint
 Proximal end of clavical articulate the clavicular notch
of manubrium of sternum and with the cartilage of 1st
rib
 Fibro cartilagenious disc improve the fit of articulating
bone and act as shock absorber.
 Characteristics
 Modified ball and socket joint
 Major axis of rotation for the movement of clavical and
scapula
Characteristics of sternoclavicular
joint
 Movement in frontal and transverse plane and
farward and backward saggital plane rotation
 Rotation occur during shrugging of shoulders,
Elevation of arms above head
 Close pack position of SC joint occur with max.
shoulder elevation
Sternoclavicular joint
Sternoclavicular joint
Acromioclavicular joint
 Articulation of acromion process of scapula with distil
end of clavicle is known as acromioclavicular joint
 Characteristics
1) Irregular diarthrodial joint
2) Allow limited motion in three plane
3) Rotation occur at AC joint during arm elevation
Characteristics of AC joint
 Close pack position of AC joint occur when arm is
abducted at 90 degree
Acromioclavicular joint
Coracoclavicular joint
 This joint is a syndyesmosis ( joint surface is bound by
ligament)
 Coracoid process of scapula and inferior surface of
clavicle bound together by coracoclavicular ligament
 This joint permits little movement
Coracoclavicular ligament
Glenohumeral joint
 Ball and socket joint, head of humerus articulate with
glenoid fossa of scapula.
 Most freely moving joint in human body
 Hemispherical head of humerus has three to four time
the amount of surface area as the shallow glenoid
cavity
 Glenoid fossa is also less curved as compare to head of
humerus, enabling humerus to move linearly across
surface of glenoid fossa in addition to rotational
capability
Movement in glenohumeral joint
 Flexion
 Extension
 Abduction
 Adduction
 Horizontal adduction, abduction
 Medial rotation and lateral rotation
 circumduction
Characteristics of glenohumeral
joint
Glenoid fossa composed of part of joint capsule, tendon
of long head of biceps,and glenohumeral ligament
located on the periphery of glenoid fossa deepen fossa
and add stability to glenohumeral joint
 Ligaments
 Superior, middle and inferior glenohumeral ligaments
on anterior side of joint
 Coracohumeral ligament on superior side of joint.
 Transverse humeral ligament
Ligaments of glenohumeral joint
Rotator cuff muscles and Jt.
stability
 Tendon of four muscles also join the joint capsule.
these are rotator cuff.
 The rotator cuff muscles are the group of muscles in
the upper arm and shoulder area that support the or
stabilize the shoulder area. The four muscles that
make up the rotator cuff are the supraspinatus,
infraspinatus, subscapularis, and the teres minor
muscles. Reffered to as SITS
Factors contributing to stability
 Supraspinatus, infraspinatus teres minor participate in
lateral rotation
 Subscapularis causes medial rotation
 Rotator cuff surround the shoulder from posterior,
superior and anterior side
 tension of theses muscles pulls the head of humerus
toward glenoid fossa contributing to minimal joint
insability.
Factors contributing to stability
 Negative pressure within capsule of joint also helps to
stabilize the joint
 Joint is most stable in closed-pack position
 Abducted and laterally rotated
Rotator cuff
Scapulothoracic joint
 Region between anterior scapula and thoracic wall is
referred to scapulothoracic joint, as scapula can move
in both saggital and frontal plane.
1) Functions of muscles attaching to scapula
2) Either stabilize shoulder region
3) Or facilitate movement of upper extremity through
appropriate positioning of glenohumeral joint ex.
Rhomboids during overhead through
Bursae
 Small fibrous sacs that secrete synovial fluid internally
to lessen friction between soft tissues around joints.
 Shoulder contains:
 Subcoracoid bursa
 Subscapularis bursa
 Subacromial bursa
Bursae
 Subscapular and subacromial bursae manage
friction between the subscapularis muscle against
 the neck scapula
 Head of humerus
 Coracoid process
 Subacromial bursae between acromion process of
scapula and coracoacromial ligament above and
glenohumeral joint below
 Cushion rotator cuff muscle (supraspinatus) from
overlying acromion
 May become irritaed when repeatedly compressed
during overhaed arm action
Movements of the Shoulder
Complex
 Humerus movement usually involves some movement
at all three shoulder joints
 Positioning further facilitated by motions of spine
 Scapulohumeral Rhythm
Movements of the Shoulder
Complex
scapulohumeral
rhythm: a regular
pattern of scapular
rotation that
accompanies and
facilitates humeral
abduction
 Elevation of scapula in all planes accompained by 55
lateral rotation
 Rotation of scapula maccounts for a part of total
humeral motion when arm is elevated
 during 1st 30 degree humeral elevation contribution of
scaplula is one-fifth
 Beyond 30 degree elevation scapula rotate 1 degree for
every 2 degree movement of humerus
 This importatnt co-ordination of scapular and
humeral movement is known as scapulohumeral
rhythm
 Scapulohumeral rhythm provide greated range of
movement
Clavical elevated through 35-45 deg. Movement at
sternoclavicular joint during 1st 90 deg. Of arm
elevation
Rotation of acromioclavicular joint during first 30 degree
of humeral elevation and again when arm moved from
135 to max.
Positioning of humerus also facilitated by movement of
spine
Movement patteren of scapula also differ in children
from adults
Movements of the Shoulder
Complex
 Muscles of the Scapula
 Muscles of the Glenohumeral Joint
 Flexion
 Extension
 Abduction
 Adduction
 Medial and Lateral Rotation of the Humerus
 Horizontal Adduction and Abduction at the Glenohumeral
Joint
Muscles of the Scapula
 Functions:
 1) stabilize the scapula when shoulder complex is loaded
 2) move and position the scapula to facilitate movement
at glenohumeral joint
 Are:
 Levator scapula, rhomboids, serratus anterior, pectoralis
minor, subclavius, and four parts to trapezius.
Movements of the Shoulder
Complex
What muscles contribute to flexion at the
glenohumeral joint?
• anterior deltoid
• clavicular pectoralis major
• assisted by:
• coracobrachialis
• short head of biceps brachii
Movements of the Shoulder
Complex
What muscles contribute to abduction at
the glenohumeral joint?
• middle deltoid
• supraspinatus
Movements of the Shoulder
Complex
What muscles contribute to adduction at
the glenohumeral joint?
• latissimus dorsi
• teres major
• sternocostal pectoralis
• assisted by:
• short head of biceps brachii
• long head of triceps brachii
Movements of the Shoulder
Complex
What muscles contribute to medial
rotation of the humerus?
• subscapularis
• teres major
• assisted by:
• pectoralis major
• anterior deltoid
• latissimus dorsi
• short head of biceps brachii
Movements of the Shoulder
Complex
What muscles contribute to lateral rotation
of the humerus?
• infraspinatus
• teres minor
• assisted by:
• posterior deltoid
Movements of the Shoulder
Complex
What muscles contribute to horizontal
adduction of the humerus?
• pectoralis major
• anterior deltoid
• coracobrachialis
• assisted by:
• short head of biceps brachii
Movements of the Shoulder
Complex
What muscles contribute to horizontal
abduction of the humerus?
• infraspinatus
• middle and posterior deltoid
• teres minor
• assisted by:
• teres major
• latissimus dorsi
Loads on the Shoulder
 Articulation of shoulder girdle are inter connected ,
they function as unit in bearing loads. As
glenohumeral joint provides direct mechanical
support to arm, it sustains much load as compare to
other shoulder joints
 Body weight acts at body center of gravity.
 Likewise weight of each body segment acts at
segmental center of mass
Loads on shoulder
 The moment arm of entire arm segment with respect
to shoulderis Perpendicular distance between weight
vector and shoulder
 With elbow flexion, upper arm and forearm/hand
segments must be analyzed separately.
 Muscles contract to support the extended arm,
glenohumeral joint sustains compressive forces
estimated to reach 50 prcnt of body weight.
Loads on shoulder
 Load reduced by half with maximal elbow flexion,
due to shortened moment arm of forearm and hand.,
this can also produce rotational torque to humerus
that require activation of additional shoulder muscles.
 Because of great effect of arm position on shoulder
loading, ergonomists suggest that worker seated at
desk or table attempt to position arm at 20 or less
degree abduction and 25 or less degree flexion
Common Shoulder Injuries
 Dislocations
 Rotator Cuff Damage
 Impingement Theory
 Subscapular Neuropathy
 Rotational Injuries
dislocation
 GH joint is most commonly dislocated joint in body
 Loose structure of glenohumeral joint enables extreme
mobility and less stability.
 Dislocation can occur in anterior, posterior and inferior
direction
 Coracohumeral ligament prevent superior dislocation.
 Dislocation typically occur when humerus is abducted
and externally rotated, with anterior- inferior
dislocation most common
Factors predispose to joint
dislocation
 Factors are
 Structural variation that include
 Inadequate size of glenoid fossa, anterior tilt of
glenoid fossa, inadequate retroversion of humeral
head.
 Deficits in rotator cuff muscles.
Causes of dislocation
 Dislocation may results from large external force.
During accident , during contact sports such as
wrestling and football.
 Once the joint dislocate stretching of surrounding
collagenous tissue beyond their elastic limit
predispose it to subsiquent dislocation.
 There may be laxity in capsule of GH joint due to
genetic factor, strengthning of shouldre muscles
required in this condition
Rotator cuff damage
 Common injury in people who engage in forceful
overhead movement. Typically involving abduction of
flexion along with medial rotation.
 Supraspinatus muscle is commonly affected.
 Because its blood supply is most susceptible to
pressure.
Changes in the joint
 Hypermobility of anterior shoulder capsule
 Hypomobility of posterior shoulder capsule
 Excessive external rotation coupled with limited
internal rotation
 General laxity of GH joint
Factor leads to impingement
syndrome
 Anatomical factors( flat acromion with small
inclination, bony spur at AC joint, superiorly
positioned humeral head)
 IMPINGMENT THEORY : genetic factor results in
formation of narrow space between acromion and
head of humerus
 ALTERNATE THEORY : major factor of inflammation
is repeated overstretching of muscle tendon unit.
Factor leads to impingement
syndrome
 Rotator cuff muscles weak ,daltoid pull the humeral
head up too high in abduction resulting in
impingment
Rotational Injuries
 Tears of labrum
 Mostly in anterior-superior region
 Tears of rotator cuff muscles
 Primarily of supraspinatus
 Tears of biceps brachii tendon
 EXAMPLE
 ex. Of forceful rotational movements Throwing ,
serving in tennis, spiking in volleyball
Mechanism of rotational injury
 Tear to glenoid labrum
 Attaching muscles don’t stabilize the humerus,
humerus articulate with glenoid labrum instead of
glenoid fossa. Contributing to tear of labr.
 tear of rotator cuff
 primarily supraspinatus during deceleration phase of
vigorous rotational activities
 Due to forceful rotational movements
 Also: calcification of soft tissues, degenerative changes
in articular surfaces, bursitis
Mechanism of rotational injury
 Tear to glenoid labrum
 Attaching muscles don’t stabilize the humerus,
humerus articulate with glenoid labrum instead of
glenoid fossa. Contributing to tear of labrum.
 tear of rotator cuff
 primarily supraspinatus during deceleration phase of
vigorous rotational activities
Mechanism of rotational injury
 Tear of biceps brachii
site of attachment near glenoid fossa may result from
forceful development of tensionin the biceps when it
negatively accelerates the rate of elbow extension
during throwing
Mechanism of rotational injury
Other pathologies causes problem in throwing
movements

calcification of soft tissues
 degenerative changes in articular surfaces
 bursitis
Subscapular neuropathy
 Degeneration of infraspinatus, with loss of strength
during external rotation
cause is repeated stretching of nerve.
Common in volleyball players.
Structure of the Elbow
 Is a hinge joint is simple hinge joint, in which there are
three joints.
 Humeroulnar Joint
 Humeroradial Joint
 Proximal Radioulnar Joint
 Are enclosed in the same joint capsule and reinforced
by anterior and posterior radial & ulnar collateral
Humero-ulnar joint
 Hinge joint at elbow
 Ovular trochlea of humerus articulate with
trochlear fossa of ulna
 Primary movement:
 Flexion & extension
 Hyper extension in some individuals
 Restrict movement in segital plane
 Close pack position: extension
Humero-radial joint
 Immediately lateral to humero-ulnar joint
 Formed b/w capitellum of humerus and proximal end
of radius
 Gliding joint
 Close pack position: elbow is flexed 900
 Forearm supinated to 50
Proximal radio-ulnar joint
 Head of radius is bound to the radial notch of ulna by
anular ligament, forming proximal radio-ulnar joint
 Pivot joint
 Primary movement
 Supination
 Pronation
 Radius rolls medially & lateral over the ulna
 Close pack position: 50 supination
Carrying angle
 Angle b/w longitudinal axis of humerus & ulna when
arm is in anatomical position
 Ranges from 10-150 in adults
 Tends to be larger in females
 Changes with skeletal growth
 Greater on dominant side
Movement at elbow joint
 Flexion & extension
 Supination & pronation
Flexion & extension
 Muscle crossing anterior side of elbow are flexors
 Brachialis
 Brachioradialis
 Biceps brachii
Brachialis
 Anterior lower half of humerus to coracoid process of
ulna
 Strongest flexor
 Equally effective when forearm is in supination or
pronation
 Called work horse of elbow
Biceps brachii
 Upper rim of glenoid fossa and coracoid process of
scapula
 Distal attachment to radial tuberosity by single
common tendon
 More effective when forearm is supinated because it is
more stretched
 In pronation it is less taught
Brachioradialis
 Upper 2/3 of lateral supera condyler ridge of humerus
 Attach to styloid process of radius
 More effective when forearm is in neutral position
 Because base of styloid is at lateral side of radius &
muscle is slightly stretched
Extension of elbow
 Triceps
 Anconeus
Triceps
 Crosses posterior aspect of joint
 Three heads at separate proximal attachement
 Attach to olecrenon process of ulna through common
distal tendon
 Distal attachment is relatively close to axis of
movement
 Size & strength make it effective
Anconeus
 Posterior surface of lateral epicondyle of humerus
 To the lateral olecrenon process & posterior proximal
ulna
 assist in extension
 According to research: lateral & medial head of triceps
contribute to 70-90% of elbow extension
 Approximately 15% contributed by anconeus
Segments at the Elbow
 Pronation and Supination
 Involves rotation of radius around ulna
 Articulations:
Proximal and distal radioulnar joints (both pivot joints)
 Middle radioulnar joint (syndesmosis)
A form of fibrous joint in which opposing surfaces that are
relatively far apart and attached by ligaments

PRONATION
 main muscle Pronator quadratus attached to distil
ulna and radius
 Pronator teres also assist in pronation when pronation
is resisted.
Supination
 Supinator muscle is responsible for supination
attached to lateral epicondyle of humerus and lateral
proximal third of humerus
 When elbow is in flexion tension in supinator lessen
and biceps assist in supination. When elbow flexion
to 90 degree or less biceps is positioned so that it acts
as strong supinator.
LOADS ON ELBOW
 Non weight bearing join
Load on elbow during ADLS
 During eating and dressing compressive load
300N(671lb)
 Rising from chair e arm supported 1700N(382)
 Pulling of table across the floor 1900N(427lb)
LOADS ON ELBOW
 During moderate activity humeroulnar force 1600N
and humeroradial force 800N
 During push up exercises peak forces on each elbow is
45% of body wt
 Greater posterior and varus forces are generated when
hands are medially rotated as compare to neutral or
laterally rotated positions
Load on elbow during sports
activities
 During baseball throwing elbow undergoes a
valgus torque of 64 N-m and 1000N of muscle
force is required to prevent dislocation
 During gymnastic skills e.g handspring and
vault,the elbow is weight bearing joint
 Maximal isometric conraction during fully
extended position joint produce compressive force
two times the body weight
 As ticeps attachment to ulna is closer to the elbow
joint centre than the attachments of brachialis on ulna
and biceps on the radius
 So extensor moment arm is shorter than the flexor
moment arm.
 Extensors produce more force than flexors to produce
same torque
 This translates to large compressive forces at elbow
during extension than flexion movement when
movements of comparable speed and force
requirements are executed
 Due to shape of olecranon, ticeps moment arm also
varies with the position of elbow.
 The triceps moment arm is larger in full extension
than flexion past 90.
COMMON INJURIES OF THE ELBOW
 Stable joint
 Dislocation and overuse injuries
dislocations
 Forced hyperextension of elbow…post displacement of
coronoid process of ulna with respect of trochlea of
the humerus
 This displacement stretches the ulnar collateral
ligament which my rupture anteriorly.
dislocations
 Not common as glenohumeral
 Occurs in individuals under age 30 mostly during
sports
 Mechanism is fall on an outstretched hand or a
forceful twisting blow
 Subsequent stability of a once dislocated elbow is
impaired particularly with humeral fracture or rupture
of ulnar collateral ligament
dislocations
 Large number of blood vessels and nerves are passing
around elbow
PULLED ELBOW or NURSEMAID’S ELBOW
 dislocation in younger children age 1-3
OVERUSE INJURIES
 After knee it is common in elbow
 Stress injuries to the collagenous tissues are
progressive
 Ist symptom is inflammation and swelling then
scarring of soft tissues
 In progressive damage deposition of calcium
Lateral epicondylitis
Inflammation or micro damage to tissue on lateral side
of distal humerus
 Overuse of wrist extensors
 Tennis elbow due to 30-40%common injury in tennis
players
 Age 35-50
 Due to poor technique and improper equipment
Medial epicondylitis
 little leaguer’s elbow
 Injury at medial aspect of distal humerus
 During pitching Valgus strain imparted to the medial
aspect of the elbow during initial stage ,when trunk
and shoulder are brought forward ahead of forearm
and hand ,results in epicondylitis
 Medial epicondyle avulsion fracture ….forceful
terminal wrist flexion
Medial epicondylitis
 Injuries to elbow are chronic
 Injury to ulnar collateral ligament valgus instability
 Valgus instability is common in repetitive throwing
 In right handed golfers, lateral epicondylitis on left
side and medial epicondylitis on right side
Structure of the Wrist
wrist composed of
1. Radiocarpal joint
2. Intercarple articulation
1. Radiocarple joint :
most movement occur at radiocarple joint.
radius articulate with LUNATE, SCAPHOID AND
TRIQUITRM
cartilagenous disc present : radiocarple joint and distil
radioulnar joint
MOVEMENTS:
•
Sagittal plane movements
•
Frontal plane movements
•
Circumduction
Closed packed position:
wrist extension and radial deviation
Radiocarple joint :
radio carple joint capsule is Reinforced by: volar radiocarpal,
dorsal radiocarpal, radial collateral and ulnar collateral
ligaments
Movements of the Wrist
 Flexion
 Extension and Hyperextension
 Radial Deviation
 Ulnar Deviation
 circumduction
 Retinacula
 Fascia around wrist thickened into strong fibrous band
called retinacula
 protective passageways for tendons, nerves and blood
vessel to pass through.
1) Flexor retinacula
2) Extenser retinacula
Movements at the Wrist
What muscles contribute to flexion at the
wrist?
• flexor carpi radialis
• flexor carpi ulnaris
• palmaris longus
• assisted by:
• flexor digitorum superficialis
• flexor digitorum profundus
•Assist when fingers are extentended.
Movements at the Wrist
What muscles contribute to extension at
the wrist?
• extensor carpi radialis longus
• extensor carpi radialis brevis
• extensor carpi ulnaris
• assisted by:
• etensor pollicis longus, extensor
indicis,extensor digiti minimi ,
•extensor digitorum
Joint Structure of the Hand
 Carpometacarpal (CM)
 Metacarpophalangeal (MP)
 Interphalangeal (IP)
Structure of the Joints of the
Hand
What are the carpometacarpal joints?
• the carpometacarpal joint of the thumb
is a saddle joint
• the other carpometacarpal joints are
gliding joints
Structure of the Joints of the
Hand
intermetacarpal joints:
•between the metacarpals
• share joint capsules with the
carpometacarpal joints
•Reinforcd by dorsal, volar and interosseous
CM ligament.
Metacarpophalangeal joint
•Condylar joint between
•rounded distil head of metacarples and
proximal end of phalanges
•Form nuckles of hand
•Each joint enclosed by capsule
•Reinforced by collateral ligaments
Structure of the Joints of the
Hand
interphalangeal joints?
• proximal and distal interphalangeal
joints of the fingers
• interphalangeal joint of the thumb
• all are hinge joints
•Closed pack position: full extension
Movement of hand
 Carometacarple joint of thumb
 ball and socket joint
 Allow large range of movement
Carometacarple joint of 2nd to 4th finger:
 Slight movement due to constrainin
 Ligaments.
 More movement permitted at 5th CM joint
Movements of the Hand
motions at metacarpophalangeal joints
2-5
• flexion
• extension
• abduction
• adduction
• circumduction
•At 1st MCP circumduction doesn’t take place
bcz of shape of joint
Movement at Interphalangeal
joints
 Flexion
 Extension
 Slight hyperfxtension in some
 Hinge joints
Movements of the Hand
What muscles are responsible for
motions of the hand?
• there are nine extrinsic muscles with
attachments both proximal and
distal to the wrist
• there are ten intrinsic muscles with
both attachments distal to the wrist
Common Injuries of the Wrist and
Hand
 Sprains and strains fairly common, due to breaking a
fall on hyperextended wrist
 Certain injuries characteristic of sport type
 Metacarpal fractures and football
 Ulnar collateral ligament and hockey
 Wrist fracture and skate/snowboarding
 Wrist in non-dominant hand for golfers
 Carpal Tunnel Syndrome