Exam 2 Lectures Flashcards
Four actions at the elbow joint
Flexion, extension, pronation, supination
Position of elbow and arm in anatomical position
Elbow - extended; forearm - supinated
What are the bones that make up the elbow joint
Distal humerus and proximal radius and ulna
What runs between the medial epicondyle of the humerus and the olecranon process of the ulna
Ulnar nerve
The head of the radius articulates with what
radial notch on the ulna
Medial epicondyle is for
flexors and ulnar nerve
Lateral epicondyle is for
extensors and anconeus
Ulnar is larger more…. radius is larger more….
proximally; distally
Position of radius and ulna in supination
Side by side
Position of radius and ulna in pronation
radius rotates over the ulna
Muscles must attach to what to be involved in pronation
Radius
What does the biceps brachii insert on
radial tuberosity
Flexion in the supinated position
biceps brachii
Flexion in the pronated position
Brachialis
Carrying angle
lateral deviation of the forearm (looking at the angle relative to the humerus)
Carrying angle in men and women
Men: 5-10 degrees; Women 10-15 degrees
When you can assume a fracture that didn’t heal properly when looking at the carrying angle
If the forearm is medially deviated
ROM for elbow flexion - actively and passively
Passively: 150-160 (bc your muscles aren’t contracted and aren’t getting in the way of flexing)
Actively (or in supination): 90
Articulations at elbow joint
Humeroulnar joint (uniaxial hinge) Humeroradial joint (uniaxial hinge) Radioulnar joint (uniaxial pivot)
What surrounds the articulations at the elbow joint
Articular cartilage, fat pads, synovial membrane, Joint capsule
Joint capsule around elbow joint:
Fibers run in all directions; weak anteriorly and posteriorly
Ligaments around elbow joint
Annular ligament; radial collateral ligament; ulnar collateral ligament
Location of Radial (lateral) collateral ligament
Spans from lateral epicondyle - blends with annular ligament
Location of Ulnar(medial collateral ligament)
Spans from medial epicondyle - coronoid process and olecranon of ulna
Three parts of ulnar collateral ligament
Anterior band - taut in extension
Posterior band - taut in flexion
Oblique band - deepen the trochlear notch
Damage to radial and ulnar collateral ligaments
- Laxity over lateral epicondyle could mean injury to radial collateral ligament
- More common injury is to ulnar collateral ligament (even though stronger) - corrected by Tommy John’s surgery
Oblique cord
ligament that connects the radius and ulna (ulnar tuberosity to below radial tuberosity)
Annular ligament
- Surrounds 7/8 of radial head
- Act as a joint surface (bc of articular cartilage lining the ligament)
- Helps with pronation and supination
- Fracture to radial head could cause callousness and get in the way of the annular ligament working
Interosseus membrane
Fibrous- syndesmosis (Help prevent proximal displacement of radius over ulna)
Elbow is fairly stable in
extension (bc olecranon is locked in olecranon fossa)
What kind of stress does radial collateral ligament protect against
Varus stress (stress from medial side or adduction)
What kind of stress does ulnar collateral ligament protect against
Valgus stress (from lateral side or abduction)
Main blood supply to the arm
Brachial artery
Significance of brachial artery
Used for blood pressure
Veins
Superficial branches - cephalic and basilic; Deep branch - brachial
Boundaries and contents of the cubital fossa
Medially - pronator teres; laterally - brachioradialis; Superiorly - imaginary line from medial and lateral epicondyles; floor - supinator and brachialis; roof - brachial and antebrachial fascia
Contents: Radial nerve Biceps tendon Brachial Artery Median Nerve Medial and lateral cutaneous nerves and median cubital vein run over subcutaneous tissue
Osteofacial compartments are formed by
Deep fascia surrounding the muscles, bone, intermuscular septa projecting from fascia, interosseous membranes (in the forearm)
What do osteofacial compartments share
Innervation and blood supply
What is the primary arm flexor
Brachialis (bc it is wider, takes up more area, closer to the bone)
What flexes the arm if the musculocutaneous nerve is injured?
Brachioradialis (weak flexor) can flex the arm because it is innervated by the radial nerve
Which head of the biceps is more medial
short head
Fracture to the humerus can damage _____ which would affect the triceps function
radial nerve
What are the arm muscles innervated by
Musculocutaneous (biceps brachii and brachialis); Radial nerve (Triceps brachii; anconeus; brachioradialis)
To check for normal flexion and extension:
Flexion - condyles and olecranon form a triangle
Extension - condyles and olecranon form a straight line
fluid filled sac that allows the tendon to move over the bone and decreases friction
bursa
Subcutaneous olecranon bursitis
leaning on your elbow too much, and your elbow bursa gets inflamed
7 bursa at the elbow
Subcutaneous bursa of medial epicondyle
Subcutaneous bursa of lateral epicondyle
Bursa of anconeus
Bursa of origin of extensor carpi radialis brevis
Olecranon bursa:
-Subtendinous
-Intratendinous
-SubcutaneousWhat do you need to generate power from your hand?
A stable wrist joint (too much mobility at wrist is a liability)
Wrist is needed for
Gross motor, fine motor activities, gripping activities
What is the function of the radoiocarpal and mid carpal joints in terms of flexion and extension
The radoiocarpal joint is responsible for 2/3 of wrist extension, while the mid carpal joint is slightly more responsible for wrist flexion than the radoiocarpal joint
What is the distal radial ulnar joint
Articulation between the ulnar notch on the distal radius and the head of the ulna
What are the components of the TFCC
disc, meniscus, two ligaments
What is the importance of the TFCC disc in the distal radioulnar joint
- movement is radius moves around fixed ulna
- TFCC disc is in between the ulnar head and ulnar notch on the radius
- The TFCC disc is important because it connects the radius and ulna ends together and it helps make the articulation and movement smoother
- separates the DRUJ from the radoiocarpal (wrist joint)
Functions of the distal radioulnar joint
- Pronation and supination
- Transmits load from hand to forearm
What can you see when you make a fist
- Flexion at your MCP joints
- Flexion increases with index finger having the least and pinky having the most which is important for gripping
What motions allow you to make and release a fist
Flexion and extension
Blood supply of the hands is
very good supply of blood to hands
-Hands are normally warm, tend to get cold when nervous
Explain the CMC joint of the thumb
- Synovial, saddle
- Loose capsule
- Common site of osteoarthritis
- Increased mobility, decreased stability
- Site of flexion,extension,abduction,adduction,opposition,reposition of thumb
