L01 - UPPER LIMB BONES AND JOINTS Flashcards
What are the upper limb regions?
- Shoulder
- Arm (brachium)
- Forearm (antebrachium)
- Hand (manus)
Name of digits of the hand?
1 = thumb/ Pollex 2 = Index finger 3 = Middle finger 4 = Ring finger 5 = Little finger/ Digitus minimus
Name all the bones in the superior appendicular skeleton (free upper limb)
Scapula Clavicle Humerus Radius and Ulna Carpals Metacarpals Phalanges
Describe the shape of the clavicles?
S shape, double curvature in horizontal plane
Medial 2/3 of the shaft is convex anteriorly
Lateral 1/3 of shaft is concave anteriorly, flattened
Compare the 2 ends of the clavicles? What do they articulate with?
Sternal end: enlarged, triangular where it articulates with manubrium of sternum at sternoclavicular joint
Acromial end: Flat where it articulates with acromion of the scapula at acromioclavicular joint
Compare the superior and inferior surface of the clavicle?
Superior = smooth Inferior = rough, with tubercules, ridges and grooves
(where strong ligaments bind the clavicle to the 1st rib near sternal end and suspend the scapula at the acromial end )
Location and attachment of conoid tubercule?
Conoid tubercule = near acromial end of clavicle
Attach to conoid ligament (medial part of coracoclavicular ligament) to suspend the upper limb
Location and attachment of subcalvian groove?
Medial 1/3 of shaft of clavicle at inferior surface
Attach subclavius muscle
3 roles of the clavicles?
1) Transmit shock from upper limb to axial skeleton
2) Boundary of cervicoaxillary canal»_space; protect neurovascular bundle supplying upper arm
3) Crane- like strut to suspend the scapula and upper limb, keeping them away from the trunk for maximum freedom of motion
What are the bony prominence/ features of the scapula?
- Acromion
- Glenoid fossa
- Inferior angle
- Superior angle
- Coracoid process
- Spine of scapula
- Scapular notch
What are the fossas on the anterior and posterior surfaces of the scapula?
Posterior surface: Convex:
- Supraspinous fossa and Infraspinous fossa divided by Spine of Scapula
Anterior/ Costal surface: Concave:
- Subscapular surface, large
Role of the 3 fossa of the scapula?
For muscle attachment
Medial attachment of deltoid muscle?
Deltoid tubercule of the scapular spine = medial point of deltoid attachment
Describe the shape and function of the glenoid fossa?
Shallow, Concave, Oval, at lateral surface of scapula, forms glenoid cavity:
Receives and articulates with head of humerus ar glenohumeral joint
Location and function of the Scapular notch?
Superior border of scapula, at medial 2/3
Forms inferior border of foramen for suprascapular nerve and ligament
What are the tubercules at the superior and inferior edges of the glenoid fossa?
Supraglenoid tubercule and Infraglenoid tubercule
For muscle attachment
What attaches to the coracoid process?
Coracoid process provide inferior attachment for passively supporting coracoclavicular ligament
What are the bony features at the Head of the humerus?
Between surgical neck and head of humerus:
Lateral = Greater tubercule (palpable)
Medial = Lesser tubercule
In between greater and lesser tubercule = Intertubercular (bicipital) groove
What are the bony features at the shaft of humerus?
Deltoid tuberosity
Towards condyle inferiorly:
- Lateral supracondylar ridge
- Medial supracondylar ridge
Function of intertubercular bicipital groove?
Passage for tendon of Long head of bicep muscle
What are the bony prominence at the condyle of humerus?
- Radial fossa (lateral)
- Coronoid fossa (medial)
- Lateral and medial epicondyle
- Capitulum (lateral) and Trochlea (medial)
What are the grooves and fossa at the posterior surface of the humerus?
Groove for ulnar nerve
Groove for radial nerve (radial groove/ spiral groove)
Olecranon fossa
What passes through the radial groove of the humerus?
Radial nerve and deep artery
Pass between medial and lateral head of the triceps brachii muscle
What makes up the condyle of the humerus?
Trochlea, capitulum, olecranon, coronoid and radial fossa
Function of lateral capitulum and medial trochlea at the condyle of humerus?
Lateral capitulum = articulation with the head of radius
Medial trochlea = pulley-like, articulation with proximal end of ulna
Function of the coronoid fossa of humerus?
At anterior surface
Receives the coronoid process of ulna during full extension of elbow
Role of olecronon fossa at the condyle of humerus?
At posterior surface
Receives olecranon of ulna during full elbow extension
Role of radial fossa?
At anterior surface
Receives head of radius during full elbow extension
Two bones of the forearm?
Radius and ulna
Ulna is medial, longer, stabilizes the forearm
What forms the walls of the trochlear notch?
Olecranon and coronoid processes of proximal ulna
What links the shafts of radius and ulna together?
Interosseous membrane
What is the root of the brachialis muscle?
Inferior to the coronoid process = tuberosity of the ulna, where tendon of brachialis muscle attaches
Compare the diameter of ulna and radius from proximal to distal?
Ulna: Proximal = broad, Distal = thin
Radius: Proximal = thin, Distal = broad
Location and function of the radial notch of proximal ulna?
Lateral side of coronoid process
Receives broad periphery of head of radius
Location of styloid process on ulna?
Distal end
Location and function of Dorsal tubercule of radius?
At distal radius
Lies between shallow grooves for passagee of tendons of forearm muscles
What demarcates the proximal head and shaft of the radius?
Radial tuberosity at medial proximal radius
What is the role of the interosseous membrane?
helps transmit force from raidus to ulna, thus to humerus
What are the carpal bones?
8 bones (Some Lovers Try Positions That They Can't Handle)
Proximal row lateral to medial:
Scaphoid (boat-shape), Lunate, Triquestral, Pisiform
Distal row lateral to medial:
Trapezium, Trapezoid, Capitate, Hamate
What does the trapezium carpal bone articulate with?
Scaphoid anteriorly
Trapezoid medially
1st metacarpal, 2nd metacarpal
What does the trapezoid carpal bone articulate with?
Trapezium
Scaphoid
2nd metacarpal
Capitate
What does the capitate carpal bone articulate with?
Trapezoid Hamate Lunate Scaphoid 3rd metacarpal
What does the hamate bone articulate with ?
4th, 5th metacarpal
Capitate
Triquetral
What type of joint is most common in the body?
Synovial joints
Describe a synovial joint space.
Two ends of bones covered by articular hyaline cartilages
Joint space enclosed by fibrous capsule
Synovial membrane lines inner surface of joint capsule
Synovial membrane secretes synovial fluid into joint cavity for lubrication
Describe the function of bursa?
Herniated synovial membrane that lubricates tendon or muscles that lie over it
What does the range of motion and joint stability depend on?
- Shape of articular surfaces, (e.g. hinge joint = restricted movement)
- Ligaments (strong or weak)
- Muscle tone (= low level of contractile activity in relaxed muscles to stabilize joint)
Describe the structure of the sternoclavicular joint?
- Medial end of clavicle articulates with “socket” formed by manubrium and 1st costal cartilage
- Fibrocartilaginous articular disc divides joint cavity into 2 compartments: synovial double-plane joint: allows sliding / gliding
What stabilizes the sternoclavicular joint?
Stabilized by the costoclavicular ligament (between clavicle and 1st costal cartilage) and the articular disc
Describe the structure of the Acromioclavicular joint?
synovial plane joint
Small fibrocartilageinous articular disc: hangs down into joint cavity (not divided into 2 compartments)
What holds the clavicle to the scapula?
strong coracoclavicular ligament
+
Acromioclavicular joint
> > Both move in unison
What is the ROM of the clavicles?
Elevation/ depression
Protraction/ retraction
Rotation
Movement produced by muscles that act on either clavicle or scapula
Describe the shoulder joint structure?
synovial ball-and-socket joint
- Loose cuff of synovial membrane, does not cover hyaline cartilage
- Glenoid labrum: deepens glenoid fossa (increase SA), articulate with humeral head, very mobile but unstable
- Fibrous capsule: weak, loose fitting inferiorly
What nerve is damaged when the arm is hyper-abducted?
Dislocation of the humeral head causes injury to the Axillary nerve
What is the ROM of the shoulder joint?
1) Flexion / extension
2) Abduction / adduction
3) Lateral / medial rotation
4) Circumduction
What produces the abduction of the shoulder joint from 0 to 180 degrees?
- 0-90o: locked by greater tubercle coming into contact with upper margin of glenoid (articulating surface used up at 90o)
- 90-150o: involves lateral rotation of scapula (pectoral girdle)
- 150-180o (full abduction): involves movement (tilting) of spinal column
What stabilizes the shoulder joint?
Rotator cuff: muscles tone
4 muscles: Supraspinatous, Infraspinatous, Teres minor, Subscapularis
What bursa exists at the shoulder joint?
Subacromial bursa:
Lies above shoulder joint between deltoid, supraspinatus
What is painul arc syndrome caused by?
subacromial bursitis
Swelling and inflammation from old age»_space; cannot fully abduct the arm
Describe the structure of the elbow joint?
synovial hinge joint between:
1) Capitulum (pulley-shaped) of humerus
2) Trochlear notch (spanner-shaped) of ulna
Seen from medial view
What are the joints in the elbow joint cavity?
Lateral Capitulum of humerus articulate with radius by Humeroradial joint
Medial Trochlea of humerus articulate with ulna by Humeroulnar joint
Proximal radioulnar joint (shared synovial cavity) between humeroradial and humeroulnar joint
What is the carrying angle?
long axis of arm and forearm forms a carrying angle of 160 to 170 degrees
more pronounced in women
What movement of the arm makes the carrying angle ‘ disappear’?
Disappears when extended arm is pronated
What is the carrying angle used to dx?
Turner’s syndrome
What ligaments stabilizes the elbow joint?
Capsule is thickened on either side to form collateral ligaments»_space;only allow flexion/ extension
Ulnar collateral ligament – 3 bands: anterior, transverse, posterior
Radial collateral ligament: not attached to radius but to annular ligament»_space; allows independent rotation of radius
What is the axis between humeral epicondyles and olecranon when the arm is extended/ flexed?
- Extended: straight line
- Flexed: equilateral triangle
To assess dislocation, fracture
What does the axis of pronation and supination of arm pass through?
Axis passes through Centre of radial head and Base of styloid process of ulna
During pronation and supination: Ulna does not rotate, Radius rotates and crosses over (carries wrist and hand with it)
Describe the Proximal radioulnar joint structure?
synovial pivot joint
Head of radius rotates within complete circle formed by:
Radial notch of ulna + Annular ligament (attaches to radial collateral ligament then to radius)
What stabilizes the proximal radioulnar joint?
Quadrate ligament
Describe the structure of Distal radioulnar joint?
Synovial pivot joint between head of ulna and ulnar notch of radius
Triangular articular disc at distal end of ulna helps bind the radius and ulna together
Describe the structure of wrist radiocarpal joint?
synovial ellipsoid joint
Anterior Concave surface = radius + triangular articular disc (cartilage) Ulna isn’t involved
Inferior Convex surface = 3 carpal bones in proximal row (no pisiform): Scaphoid, Lunate, Triquetral
What stabilizes the wrist radioulnar joint?
Capsule thickens to form radial and ulnar collateral ligaments (like elbow joint)
Describe the ROM of abduction and adduction of wrist radioulnar joint?
- Abduction (15o): restricted by Scaphoid carpal bone
- Adduction (45o): radial styloid process lies 1-1.5cm lower than ulnar styloid process = more space on ulnar side, restricted by pisiform bone
Describe the ROM of flexion and extension of wrist radioulnar joint?
Flexion (80-90o)
Extension (~70o): less free
Wrist joint and intercarpal joints are both involved
What are the 5 types of joints in the hand?
Intercarpal Carpometacarpal Intermetacarpal Metacarpophalangeal Interphalangeal
Which intercarpal joints are involved in the flexion and extension of the wrist?
Midcarpal joint between the proximal and distal rows of carpal bones
Describe the structure of the carpometacarpal joints (CMC)?
Digit II to V = synovial plane joint
Thumb = Synovial SADDLE joint (greater ROM, allows flexion, extension, abduction, adduction, rotation, opposition)
What ROM does opposition of thumb involve?
Opposition = combination of abduction, flexion, medial rotation
Saddle joint of thumb + relatively mobile 4th and 5th CMC joints are involved
What type of joint are Intermetacarpal joints?
Synovial plane joints
What type of joints are Metacarpophalangeal joints?
synovial ellipsoid / condylar joints
Describe the ROM of MCP joints?
Can abduct and adduct only when joint is extended (when collateral ligaments are slack)
Flexion = collateral ligament is taut = stabilize joints on 2 sides
Describe the interphalangeal joint structure and ROM?
Synovial hinge joints allowing flexion and extension only
How many interphalangeal joints are there in the hand?
Thumb = 1 joint, proximal and distal phalanges
Digit II to V = 2 joints, Proximal interphalangeal joint (PIP) & Distal interphalangeal joint (DIP) separating proximal, middle and distal phalanges
