| A | B |
|---|
| wrist or... is... | carpus is a collection of bones and soft tissue structures that connects the hand to the forearm. is capable of substantial motion that augments hand and finger function |
| wrist functions | by allowing for changes in location and orientation of the hand relative to the forearm. by transmitting loads form the hand to forearm and vice versa. |
| stability of wrist is essential for... | proper functioning of the digital flexor and extensor muscles |
| wrist position affects | the ability of the fingers to flex and extend maximally and to grasp effectively during prehension |
| the wrist complex consists of multiple articulation of | 8 carpal bones with the distal radius. 8 carpal bones are divided into two rows. palmar surface of the carpus is relatively concave and constitute the floor and walls of the carpal tunnel |
| the bones of the distal row...are.. | trapezium, trapezoid, capitate and hamate, are relatively immobile transverse unit |
| proximal row... is the more... | lunate, triquetrum, scaphoid, and pisiform is more mobile row |
| radiocarpal joint | lunate and triquetrym articulate with the radius to form this joint |
| spans both rows anatomically and functinoally | scaphoid |
| enhances the mechanical advantage of the flexor carpi ulnaris | pisiform |
| ligaments of wrist are cpable of | producing bony displacements. |
| palmar ligmanets are...while the dorsal ligaments are... | thick and strong, much thinner and fewer in number |
| ligaments of wrist may be divided into | extrinsic and intrinsic components |
| extrinsic ligaments run from the... | radius to the carpus and from the carpus to the metacarpals |
| intrinsic ligaments | orginate and insert on the carpus |
| flexor and extensor muslces are... | the motors of the wrist. they control raidal and ulnar deviation as well as flexion and extension. flexor carpi ulnaris, |
| flexor muslces | flexor carpi ulnaris, flcor carpi radialis, palmaris longus |
| extensor muslces | extensor carpi radialis longus and brevis, extensor carpi ulnaris longus and brevis |
| 8 muscles orginate in the...and two orginate | in the forearm, above the elbow |
| all of the flexor-extensor muslces (except the flex carpi ulnaris tnedon) insert | on the metacarpals |
| wrist complex allow motion in how many planes? which ones | 2. flexion-extension (sagittal plane), abduction-adduction (frontal plane) |
| greatest ROM takes place from... | radial deviation and extension to ulnar deviation and palmar flexion |
| axial rotation | little to none in wrist |
| normal range of wrist flexion/extension | 85 to 90 for flexion and 75 to 80 for extension |
| about 60% of wirst flexion occurs at | midcarpal joint |
| about 66% of wrist extension occurs at | raiocarpal joint |
| normal range of wrist-radial ulanr deviation | 50 degrees with 15-20 degrees radially and 35-37 degrees ulnarly |
| functional wrist motion | the joints proximal to the wrist provide compensatory motion so even a considerable loss of wrist motion may not interfere with activities of daily living |
| surface joint motion | the multiplicity of wrist articulations and the complexity of joint motion makes it difficult to determine the center of motion for either flexion-extension or radial-ulnar deviation |
| the existence of both a proximal and a midcarpal joint in the wrist creates... | a double-hinged system that provides a great stability. |
| dynamic stability | virtually no muscles insert on the carpus to provide dynamic stability |
| compressive forces of the ...and...will cause... | long flexors and extensor will cause the carpus to buckle at the proximal and midcarpal joints |
| multiple...and the shape of ...produce wrist stability | ligaments, bones |
| in sagittal plane | both schaphoid and lunate are wedge shaped (wider at the palmar side than dorsal side) |
| a compressive load willl | rotate the schapoid and lunate into extension (thus stabilization forces directly to flexion) |
| wrist flexion is synergistic to finger... | flexion |
| wrist flexion creates...cuasing the fingers to open automaticallys | creates tension on the long extensors |
| carpal tunnel syndrome | floor and sides of tunnel are formed by the carpals and the top is formed by the transverse carpal ligament. repated wrist flexion inflames the wrist flexor tendon putting pressure on the median nerve. "too much stuff in not enough space" |
