Wrist and Hand 2 Flashcards
(29 cards)
Hand function is dependent on
- balanced mechanics of the wrist & hand
- balanced internal & external forces crossing the wrist & hand
- wrist & hand joint stability –If a joint is unstable, internal & external forces will create joint deformities and disrupt the mechanics of the wrist & hand
Wrist Stability is provided by…
- BONY CONFIGURATION OF JOINTS
- LIGAMENT (STATIC) STABILIZERS:
- Extrinsic Ligaments
- Triangular Fibrocartilage Complex
Intrinsic Ligaments - DYNAMIC STABILIZERS:
- Wrist Muscles
- Extrinsic Finger Muscles
Intact ligaments are necessary to…
- Stabilize joints
- Guide motion of bones
- Limit joint motion
- Transmit forces from hand to forearm
- Prevent dislocation of carpal bones during
movement
What do extrinsic muscles do?
Connect radius, ulna, and carpal bones
What do intrinsic muscles do?
Connects carpal bones
Where is the TFCC located?
Ulnocarpal space
What is the function of the TFCC? (4)
- Supports proximal carpal row
- Transmits forces from hand/wrist to forearm
- Securely binds distal ends of radius and ulna together
(DRUJ) to facilitate stability during forearm pronation
& supination - Allows the radius and attached carpus to freely rotate
around a fixed ulna at distal radioulnar joint
What does the Palmar Radoiocarpal Ligaments prevent when taut?
Excessive extension
What does the Dorsal Radiocarpal Ligament prevent when taut?
Excessive Flexion
What happens to internal and external forces when a joint is unstable?
Internal and External forces will create joint deformities and disrupt the mechanics of the wrist
What does the Radial Ligaments prevent when taut?
Excessive Ulnar Deviation
What does the Ulnar Ligaments prevent when taut?
Excessive Radial Deviation
What is the importance of the scapulolunate ligament being intact? (2)
- Guide motion between the scaphoid
and lunate - Facilitate wrist stability
What motion is especially noted at the Scapulolunate ligament?
Gliding Motion
Carpal bones within the Proximal Carpal Row glide during which motions?
Flexion & Extension
Radial Deviation & Ulnar Deviation
What is hand stability provided by?
- BONY CONFIGURATION OF JOINTS
- LIGAMENT (STATIC) STABILIZERS
at CMC, MCP, PIP, DIP, IP joints - MUSCLE (DYNAMIC) STABILIZERS
muscles that cross the finger joints
What does the Thumb CMC joint ligaments prevent?
excessive movements of thumb CMC during grasp
and prehension
What does the Thumb CMC joint consist of?
Base 1st metacarpal
Distal End Trapezium
What do the Dorsal and Palmar Carpometacarpal Ligaments connect?
Distal carpal row to bases metacarpal II-V
What do the Dorsal and Palmar Interacrpal Ligaments connect?
Adjacent BASES of metacarpals I-V
What do the Dorsal and Palmar Carpometacaprl and Intercarpal ligaments prevent?
Excessive movements of CMC joints II, III, IV, V
What does the Deep Transverse Metacarpal Ligaments permit and prevent?
- Permit flexible distal
transverse arch - Prevent excessive finger
abduction
What does the Deep Transverse Metacarpal Ligaments connect and bind to?
- Connect to palmar plates at heads of MCP joints and - - loosely bind adjacent
HEADS of metacarpals II, III, IV, V
What are the Volar/Palmar Plates?
Fibrocartilaginous plates at palmar surfaces
MCP and IP/PIP/DIP joints of each digit
