L10 UE Prosthetics Flashcards
Upper Limb prosthesis
less relevant than lower limb loss
15-40 times more LE amputations vs UE
Causes of UE loss
80% due to trauma in males 15-45
8% due to cancer or vascular
others are congenital, burns, infection
Forequarter/scapulothoracic Amputation
usually due to malignancy
difficult to fit w/prosthesis, tolerates a lightweight cosmetic prosthesis best if any at all
Shoulder Disarticulation
most commonly due to malignancy or electrical injury
functional prosthetic use possible and will require an external shoulder joint usually passive
Transhumeral amputation
most commonly due to trauma
prosthetic options are varied
second most common level of UE ampt
allows self-suspending socket
Elbow disarticulation
requires external elbow joint
usually only body powered prosthesis is used
Transradial
loss of hand, wrist, forearm function
commonly a result of trauma
Wrist Disarticulation
loss of hand function can retain some forearm rotation
goal is to preserve grasp or pinch
toe transfer is a possibility
Digit amputation
preserves function if can grasp
prosthetic use limits sensation
conversion to TR if no prehension
Eval Objectives
develop rapport
understand pt’s concerns
understand the pts requirements
educate
assist the pt to have achievable goals
establish relationship with prosthetist
Phantom pain
pain in missing limb/digits
Phantom Sensation
feeling like you can still move the missing limb/digits
Goals should
change as stage of care evolves acute, pre-prosthetic, prosthetic, re-integration
Prosthetic Options
- no prosthesis
- passive/cosmetic prosthesis
- body powered prosthesis
- electric prosthesis
- hybrid prosthesis (comb of 2-4)
- task-specific prosthesis
Pros of no prosthesis
sensory input
comfort
mobility
simplicity
cost
Cons of no prosthesis
lack of prehension
balance
cosmesis
Functions of prosthesis
stabilize objects
push/pull
support
Pros of Cosmetic Prosthesis
cosmesis
light weight
minimal maintenance
assists with bimanual tasks
Cons of cosmetic prosthesis
limited function
durability
Passive Prosthesis Controls
can be used as paperweight
objects can be placed in the hand
shoulder/elbow jt can be locked into positions
Pros of Body Powered Prosthesis
lighter weight
can be used in various environments
less cost
repairs can be less technically demanding
Cons of Body powered prosthesis
less grip force
functional envelope is limited
cosmesis of harness and hook
axillary anchor
Components of terminal devcies
hook
voluntary opening
volntary closed
hand
Body Powered Controls
cable and harness system captures body motion and translates it into movement of the parts of prosthesis
different motions can be separated by using different cable systems
How body powered prosthetic works
- axillary loop is primary anchor, stanless steel control cable is attached at its proximal end to straps, attaches to the thumb
- Tension is applied to movable thumb pulls away from stationary finger
- Cable housing maintains constant length of control cable, same amount of body motion is required to operate it in elbow flexion/extension
When is the strap the most efficient in body powered system?
ring of axillary straps is placed just below C7 and slightly toward the non-amputated side
Primary body motion used for transradial prosthesis is…
- GH jt flexion
- biscapular abduction can be used for actions close to midline
Figure 9 Harness System
used in transradial pts
also socket provides suspension
tail of axillary loop attaches to control cable, anchoring it
Body Powered Controls
Biscapular abduction or flexion of humerus for opening or closing, depending on mechanism
Rubber bands
prehension of volunatry opening in TD uses them
one band = 2.2 lbs
Shoulder saddle harness with chest strap
primarily used for transhumeral pts who use hybrid prosthesis
saddle provides better suspension
Harness for Transhumeral Amputee
anterior support strap originates on axillary loop just post to humeral head and attaches to AM aspect of prosthesis
suspends the prosthesis against loading and helps prevent socket rotation
Elbow Locking (body powered controls)
occurs with shoulder depression, extension, and abduction of affected side
when elbow is unlocked, GH flexion will control elbow. When its locked, GH flexion will operate the TD
Electric Prosthesis Pros
grip force
less energy expenditure
correlates with neuromuscular system
larger functional envelope
reduced or eliminated harness
hand is functional, cosmetic
Electric Prosthesis Cons
cost
weight
repairs are more demanding
can be damaged by environment
requires battery power
Electrically powered components
greifer
ETD
hand
multi-articular hand
iLimb
individual joints and individual digits move
thumb has powered rotation
BeBionic
thumb is actively positioned
14 grip patterns, 8 available at 1 time
Examples of multiarticular hands
iLimb
BeBionic
Michaelangelo (Multigrasp hand)
powered thumb that positions in lateral pinch or opposition
Electrically powered controls
less or no harness or cable required
powered by battery, activated by electrodes
contains mechanical switch
has multiple different suspensions
suction, anatomical, sleeve, harness
Anatomical suspension
pt pushes in and prosthesis suspends supracondylarly
Suction suspension
pt pulls in to create a vacuum
Switch Control
if amplitude is greater than a preset threshold then the device will execute an action at a constant speed/force
offers ingle degree of freedom control
Proportional Control
method can achieve variable speed and force based on the proportion of user input signals
degree of movement can be force, speed, position, or other mechanical outputs
Myoelectric Controls
myoelectric potential
amplification
conversion to DC voltage
electrodes
Single Inputs for myoelectric control
voluntary open, automated closing
quick-slow strategy
Dual Inputs for myoelectric control
Grip increases with duration of contraction
dual inputs can control 4 motions
Mode change
inputs to change between devices. Ex hand function to wrist function
two actions are 1. co-contraction, 2. quick-slow scheme
Quick-slow scheme
hand is quick contraction
wrist is slow contraction
Positional Control
commonly used for elbow control in transhumeral
input is linear potentiometer with 1/2” to 1” of travel that is pulled by a cable
Hybrid prosthesis
combines a feature of two or more prosthetic options –cosmetic, body-powered, electric
Amputee Rehab Protocol
healing
pre-prosthetic training
basic prosthetic training
advanced functional training
community re-integration
discharge planning
Healing/Pre-Prosthetic Training
care of residual limb
general physical rehab
psychological support
change of dominance
ADL training
myosite testing and training
Care of Residual Limb
wound care
edema control
desensitization
scar management
pain management
Wound care MD prescription
aquaphor
zeroform/adaptic
mepitel
silvadene
wet to dry dressings
sharps debridement
Edema Control
elevation
AROM
compression
manual edema mob
ice, contrast baths
Desenitization
massage
immersion
textures
mini-massager
Scar management
massage
silicone scar pads
silicone liners
kinesiotape
compression
Common contractures
shoulder
elbow flexion
forearm
Posture
make it a habit
keep it simple
prevention
awareness of tendency for forward head and forward shoulder posture
Pain control
phantom pain, sensation, residual limb pain
medical management
massage
compression
TENS
mirror therapy
recognise app
Psychological Support
referral to a professional
peer support
support organizations
listen
Recovery Process is…
enduring (quiet support)
suffering (listening, empathy)
reckoning (info, referrals)
reconciling (validation, info)
normalizing (role model)
thriving (challenge, recruit for peer)
change of dominance
feeding
brushing teeth
personal hygiene
handwriting
fasteners
containers
Myosite Testing Goals
- find a superficial muscle that pt can contract with enough strength and control to operate a myoelectric prosthesis
- in-phase if possible
- independent control between muscles
- ability to co-contract or perform quick vs slow contraction
should be as proximal within socket as possible
Common sites for myosite training
TR = wrist flexors and extensors
TH = biceps and triceps
SD = pectoralis and infraspinatus
Directions for Myosite Training
- explain muscle function and reasonable goals
- practice on uninvolved side
- clean and moisten skin
- align electrodes with muscle fibers
- place just distal to innervation zone
- maintain contact
- discuss warm-up or settling period
Remember when doing myosite training
quality not quantity
frequent rests
use games as skill improves
skill acquisition for contract/relax, contract/hold/relax, signal separation, speed, co-contraction and endurance
How to create intuitive control
stimulate kinesthetic tactile learning
focus on their learning style
cultivated over time
reimprint other half of brain w/mirror
increased repetition
innovative approaches
What is the learning style of patients?
Kinesthetic, visual, auditory, reading/writing
Elbow Myoelectric operations
flexion/extension with linear potentiometer or switch
IR/ER with manual turntable
Free swing
Shoulder Operations for Myoelectric
manual or electric lock for flex/ext
friction for abd/add
Hand operations for myoelectric
open/close
pronation/supination/rotation
wrist flexion
changing TD’s
Rotation and Wrist
friction type manual control
Flexion and wrist
manual lever control for wrist
Voluntary Opening for Body Powered
open with humeral flexion of involved side, univolved side acts as an anchor
close with rubber band tension
change the TDs
Elbow operations for body powered
elbow must be locked to operate TD
elbow is unlocked, humeral flexion on TH side will flex elbow
lock is activated by shoulder depression, humeral extension, and abduction on TH side
Arm rotation operations for body powered
pt has long TH amputation they may retain anatomic ability to rotate
if amputation is short, turntable may be added to allow for manual rotation of the humeral component
Controls Training
- Begin with prosthesis at midline
- Practice open, open partially, close
- Practice changing elbow position then open/close
- Practice change of speed and change of mode for myoelectric
- Have them mimic motions
- Have them stand and grasp objects
- Have them grasp and then release on different surface
- Incorporate all joints in activities, practice control with soft objects
- Gross coordination (pouring, turning pages)
- develop fine coordination (stacking blocks, placing small pegs, play cards)
Partial hand amputations
enormous pt population
many pts chose not to wear one
usually fit with some form of opposition post, there is no power in the post
Oppositional posts…
provide grasp
protect residual limb
Electric prostheses for partial hand
activated by pressure sensors
freedom of wrist motion
better at prepositioning
Future of UE Prosthetics
improve sensory feedback
decrease reliance on visual feedback
ossointegration
patterned recognition to increase control
simultaneous control, estimates hand in real time. more intuitive
things you can do as a PT
listen
support
creativity
energy
motivation
