Hand & Wrist Flashcards
Skeletal Structures of Hand: MC
Metacarpals (5), are divided into 3 sections:
* Base (proximal)
* Shaft (middle)
* Head (distal)
Skeletal Structures of Hand: PH & PX
Phalanges (14) P2-P5 divided into:
* Proximal
* Middle
* Distal
Pollux (2)
* Proximal
* Distal
Joints & articulations of hand bones
Phalanges:
Carpometacarpal
-Structural/Functional Classification: Gliding
-Movements: Volar/Dorsal Gliding
Metacarpophalangeal
-Structural Classification: Ellipsoid
-Functional Classification: Biaxial
-Movements: Flexion/extension, abduction/adduction
-Flexion: Volar Gliding
-Extension: Dorsal Gliding
Proximal/Distal Interphalangeal
-Structural Classification: Hinge
-Functional Classification: Uniaxial
-Movements: Flexion/extension
Proximal IP: Power grip
Pollux:
Carpometacarpal
-Structural Classification: Saddle
-Functional Classification: Biaxial
-Movements: Radial & Palmar Abduction, Opposition (w/pinky), **Adduction brings the thumb back from any direction.
Movements & Muscles of Hand: Abduction & Adduction of MCP Joints
-Dorsal Interossei (Abduction)
-Palmar Interossei (Adduction)
Movements & Muscles of Hand: Extension of 2nd-5th Fingers
-Extensor Digitorum
-Lumbricals
-Dorsal Interossei (2nd-4th, Assists)
-Palmar Interossei (2nd, 4th, & 5th, Assists)
-Extensor Indicis (2nd)
Movements & Muscles of Hand: Composite (all joints) Flexion of 2nd-5th Fingers
-Flexor Digitorum Superficialis (PIP, MCP, wrist flexion)
-Flexor Digitorum Profundus (DIP, PIP, MCP, wrist flexion)
-Flexor Digiti Minimi Brevis (5th)
-Lumbricals
-Dorsal Interossei (2nd-4th, Assists)
-Palmar Interossei (2nd, 4th, & 5th, Assists)
Movements & Muscles of Hand: Flexion of MCPs w/ Extended PIPs n DIPs (Intrinsic Plus {Duck} Position)
-Dorsal Interossei
-Palmar Interossei
-Lumbricals
-Flexor Digiti Minimi (5th)
Movements & Muscles of Hand: Thumb CMC Radial Abduction
-Abductor Pollicis Longus
-Abductor Pollicis Brevis
-Extensor Pollicis Longus (Assists)
-Extensor Pollicis Brevis (Extension)
Movements & Muscles of Hand: Thumb CMC Palmar Abduction
-Abductor Pollicis Brevis
-Abductor Pollicis Longus
-Flexor Pollicis Longus (Assists)
-Opponens Pollicis (Assists)
Movements & Muscles of Hand: Thumb CMC Flexion/Extension
-Abductor Pollicis Longus (Extension)
-Extensor Pollicis Longus (Extension)
-Extensor Pollicis Brevis (Extension)
-Flexor Pollicis Longus (Flexion)
-Flexor Pollicis Brevis (Flexion)
-Adductor Pollicis (Flexion)
Movements & Muscles of Hand: Thumb CMC Adduction
-Adductor Pollicis
-Flexor Pollicis Brevis
-Flexor Pollicis Longus (Assists)
Movements & Muscles of Hand: Thumb Opposition
-Opponens Pollicis
-Flexor Pollicis Brevis (Assists)
-Abductor Pollicis Brevis (Assists)
Movements & Muscles of Hand: Thumb MCP/IP Flexion
-Flexor Pollicis Longus (IP)
-Flexor Pollicis Brevis (MCP)
-Adductor Pollicis (Assists MCP)
-Palmar Interossei (1st, Assists MCP)
Extrinsic muscles of the hand (flexor and extension all digits)
These muscles:
*Originate proximal to the wrist
*Generate greater force
Extrinsic FLEXORS:
*Flexor Carpi Radialis & Ulnaris (assist w/movements like self-feeding, writing)
*Palmaris Longus (object grasp)
Flexor Digitorum Superficialis (flexes MCP/PIP; grasp & pinch)
Flexor Digitorum Profundus (flexes MCP/PIP/DIP; grasp & pinch)
Flexor Pollicis Longus (flexes thumb joints)
*Last 3 muscles on this list (with the median nerve) all pass through the carpal tunnel
Extrinsic EXTENSORS:
*Extensor Carpi Radialis Longus & Brevis (assists w/motions like painting a wall)
*Extensor Carpi Ulnaris (assists w/ hammering/playing violin)
*Extensor Digitorum (swiping up on a smartphone)
*Extensor Indicis (pointing at something)
*Extensor Digiti Minimi (pointing with pinky)
*Abductor Pollicis Longus (texting)
*Extensor Pollicis Brevis (giving a thumbs up)
*Extensor Pollicis Longus (giving a thumbs up)
Intrinsic muscles of the hand actions. Relationship with each other and with extrinsic
These muscles:
*Contained entirely within the hand
*Precise control
Intrinsic:
*Thenar Muscles:
-Abductor Pollicis Brevis (abducts thumb)
-Flexor Pollicis Brevis (flexes thumb)
-Opponens Pollicis (brings the thumb back to origin)
*They help each other with the movement of the thumb
*Hypothenar Muscles:
-Abductor Digiti Minimi (abducts pinky)
-Flexor Digiti Minimi (flexes pinky)
-Opponens Digiti Minimi (brings the pinky back to origin)
*They help each other with the movement of the pinky
*Together the THENAR and HYPOTHENAR MUSCLES open and close the palm.
*Palmar Interossei
-Adducts digits toward middle finger
-MCP flexion w/ PIP/DIP extension
-Ex: Holding a book/sandwich
*Dorsal Interossei
-Abduct digits
-Ex: Cutting with scissors
*Adductor Pollicis
-Adducts thumb toward the hand
-Ex: Brushing hair, turning key, swiping a credit card (lateral pinch)
*Lumbricals
-Balances flexion/extension force within fingers
-MCP flexion w/ PIP/DIP extension
-Ex: Holding a book/sandwich
Total Arc Of Motion:
Extension/Flexion measurements-
MCP +10/100
PIP -50/100
DIP 0/50
Total active motion breakdown:
100+100+50= 250
250+10= 260
260-50= 210
TAM= 210
TAM Norm: 260
*There is no plus or minus with palmar of radial abduction
*If something is expected to be “0” and they don’t make it to “0” it is a deficit (-)
*Applies for all of the following:
-DIP
-PIP
-MCP
-Elbow
Hand grasps and pinch patterns
GRASP PATTERNS:
Cylindrical: Holding a bottle
Spherical: Holding s stress ball
Hook: Holding a briefcase
Composite: Griping a bat
PINCH PATTERNS:
Tip: Index finger & thumb; pinching a coin
Lateral: Turning a key
Tripod: Holding a cookie
Closed packed position of MCPs
The intrinsic plus position (MCP joints flexed and IP joints extended)
Extensor mechanism and the function of each component including origin and insertion, innervation, action.
*Extension of the MCP, DIP, & PIP all occur with a combination of the extensor digitorum, extensor indicis, extensor digiti minimi, as well as the palmar/dorsal interossei, and lumbricals.
*Extrinsics and intrinsics coming together to make extension smoother
- The extensor tendon travels along the metacarpal past the MCP joint and splits into 3 parts
- The extensor digitorum goes along distally to join the intrinsics while the central terminates on the middle phalanx
- The palmar/dorsasl interossei run on the lateral sides of the bone and when they cross over the MCP they give a few fibers to join the middle extensor digitorum while the rest move laterally.
- The lumbricals join in further distally but by the time the interossei gives fiber the lumbricals have joined.
- The area where the digitorum and interossei terminates is called the central slip and is responsible for extending the PIP joint.
- The sagittal band keeps the extensor tendon in place. Starts underneath the MCP joint and terminates at the distal phalanx.
- Lateral bands create a terminal tendon at the distal phalanx and are held in place by the triangular ligament.
- Oblique retinacular ligament connects the DIP and PIP joint allowing them to extent together as a main function.
Digital Pulley System
Fishing pole pulley analogy:
Bone = fishing pole
Tendon = fishing line
Pulleys = loops on the rod
Meanings:
Anuular = “go around”
Cruciate = “cross over (x shaped)
Of the 5 annular pulleys, the odd numbers are on a joint (A1 proximal)
A1 Head of metacarpal or MCP joint
A3 PIP joint
A5 DIP joint
A1 indicated in a trigger finger
A2 is the most important pulley; if this pulley is damaged you will not have the
mechanical advantage to flex your fingers. Can be repaired but it can be tricky.
Cruciate are between:
-A2 & A3
-A3 & A4
-A4 &A5