Functional anatomy Flashcards
What makes up pectoral girdle
Scapula
Clavicle
Sternoclavicular joint
Acromioclavicular joint
Purpose of pectoral girdle
Increases shoulder ROM
Clavicle acts as a strut -> holds shoulders away from trunk
Without pectoral girdle
Flexion + abduction ROM
180 -> 120 degrees
Orientation of glenoid fossa
Lateral
Slightly ant
Slightly post
What happens to glenoid fossa in anatomical structure
Passive structures contribute to stability -> no energy required
What happens to glenoid fossa not in anatomical structure
Tension drops off stabilising structures
Dynamic structures contribute to stability -> energy required
Are movements of the scapula pure
No they all involve other movements slightly
Scapulothoracic function
Allows scapula motion against the ribcage
Fascia over the muscle allows: gliding and sliding movements
Contributes to shoulder ROM
What is scapulohumeral rhythm
The relationship of the movement between the scapula and humerus
What movements involve scapulohumeral rhythm
Scapula: upward rotation
Humerus: flexion/abduction
Occur synchrondously
Ratio of scapulohumeral rhythm
2: glenohumeral
1: scapulohoracic
Importance of scapulohumeral rhythm
1) increases shoulder ROM
2) Maintains optimal muscle length for effective contraction
Rotator cuff muscles provide dynamic stability by
Take up shoulder joint capsule slack during movement
Provide medial force to humeral head to centre it in glenoid fossa
Explain clavicle implication example
Small movement on medial end -> large movement on lateral end
(increases arc of movement)
AOM
Function of clavicle
Acts as strut: holds scapula laterally -> increases ROM
Curve shape -> increases mobility
Medial part: convex ant
Lateral part: concave ant
Proximal radioulnar joint during pronation and supination
Spin of radial head on radial notch of ulna
Distal radioulnar joint during pronation and supination WITH TRANSLATION
Slide and roll of ulna notch of radius on ulna head
Distal radioulnar joint during pronation and supination WITHOUT TRANSLATION
Slight extension and abduction of ulna
Rotary component
Perpendicular/vertical
Rotary component function
Contribution to bone movement at joint
Transarticular component
Parallel/horizontal
Transarticular component function
Pulls bone towards joint -> stability
Spurt
Mover
R > T
Prox attatchment further from joint
Shunt
Stabiliser
R < T
Prox attatchment closer to joint
Monokinetic
one movement one joint
Polykinetic
multiple movements multiple joints
Without speed and load
Recruit monokinetic + spurt
With load
Recruit polykinetic + spurt
With speed
Recruit mono or polykinetic shunt
Extensor retinaculum attatchment
Radius, ulna
Pisiform, triquetrum
Lateral collateral lig
Extensor retinaculum function
Prevent bowstringing
Protect underlying structures
Flexor retinuaculum attatchment
Scaphoid + trapezium -> hamate + pisiform
Flexor retinuaculum function
Prevent bowstringing
Protect underlying structures
Palmar aponeurosis attatchment
Flexor retinaculum -> deep transverse metacarpal ligaments
Palmar aponeurosis function
Aids grip
Anchors skin
Intertendinous connections attatchment
Fibrous connections between ED tendons
Intertendinous connections functions
Prevents individual IP extension
-> hand opens as unit
Extensor retinaculum (DDE) attatchment
Forms aponeurosis from ED tendons
Extensor retinaculum (DDE) function
Ensures IP joints extend simultaneously (digital sweep)
Fibrous sheath location
Tunnels for the flexor tendon
(in digits)
Fibrous sheath function
Acts as pulleys for the flexor tendons
Binds FT onto the bones
Synovial flexor sheath location
Surround each tendon as it passes under fibrous sheath
Synovial flexor sheath function
Allows friction free gliding of tendon under fibrous sheath
Grip position at rest
Palm = hollow
Finger = flexion
Thumb = slightly opposed + flexed
Grip position of function
Wrist = slightly dorsiflexed
Finger = IP slight flex -> MCP flex
Thumb = slighlty opposed + flexed
Power grip characteristics
Large objects
Force required
Max hand contact
Full hand
Precision grip characteristics
Small objects
Less force required
Lateral digits
Limited skin contact
Power grip joint positions
Thumb abd/add
Finger flexion
Palm cupped
Wrist dorsi +/ ulnar deviation
Precision grip joint positions
Thumb opposed
Finger MCP flexion
Digital sweep
Longest path taken by the fingertips as the hand closes
Digital sweep whats involed
Lumbricals and interossei moderate long flexors and extensors
Fibrous sheath purpose
Prevents bowstringing within the digits
-> increases leverage + efficiency
Movements of clavicle steps
1) Scapula upward R produces clavicle elevation
2) Tension in costoclavicular ligament pushes movement lateral
3) Some elevation at AC joint
4) Increases tension in concoid ligament locks in posterior clavicle
5) Posterior rotation of clavicle
6) Elevation in AC joint -> increases shoulder ROM
