UE AMPUTATION- ASYNCH Flashcards
prosthesis
artificial body part
residual limb
remaining limb after amputation
sound side
limb that was not amputated
don and doff
taking on and off prothesis
socket
the interface between the residual limb and prosthesis
terminal device
UE specific
hand functioning device in UE prosthesis
suspension
how the prosthesis is attached to the body
force
how is the force applied through the body or with myoelectric control or external motors?
excursion
how much range of motion you need to operate the UE prosthesis
Only ___ percent of patients with amputation have UE amputation
9%
-most of these are due to traumatic causes
-rejection rates of UE prostheses are quite high
-proficiency with UE takes much more time and effort than LE
-functional difficulty with UE prosthesis directly proportional to amputation level
Types of UE prostheses:
-shoulder disarticulation
-trans-humeral
elbow disarticulation
-trans-radial
wrist disarticulation
-trans-metacarpal
partial hand
Power Strategies for prosthesis
how you move the limb in order to generate force
ex: harness system
What is the most common cause for UE amputations in the US
TRAUMA
–> as opposed to LE : vascular disease
Control strategies for prosthesis
how you manipulate the device that is linked onto the limb (hook, hand, ex)
-ex: cable system controlled with protraction of scapula
Types of UE suspension systems
1.) harness
2.) pin-lock liner
3.) suction
4.)anatomical/self-suspending
Harness suspension facts
System of straps and buckles about the shoulders, back and chest.
PRO
-simple
-easy maintenance
-durable
-ease of don and doff
-many variations –> depends on use and need of the individual
-good if handling heavy loads
CON
-can be uncomfy –> can cause impingement on neurovascular supply
-poor cosmesis (appearance)
USED FOR:
-all amputation levels
-harness system often used in combo with pin-lock system
-only option for shoulder disartic. or very short transhumeral amputations
EXAMPLES:
-figure of 8
-shoulder saddle and chest strap (no strap on CL UE)
-expanded cross point (figure of 8) connection in back
Pin lock liner suspension facts
Silicone or Gel garment worn on the surface of the limb with a distal attachment point which engages a mechanical lock.
PROS
-comfortable
-cushions bony prominences, reduces shear forces
CONS
-somewhat difficult to don (only one UE to help)
-harnessing is usually still needed
USED FOR
-ideal for passive protheses
-mid-short length TH and TR
suction suspension facts
skin-tight fit, seal to walls of socket, one-way expulsion valve (don’t always have an interface between inner liner and socket)
PROS
-interface with myoelectric control
-reduce or eliminate harnessing
CONS
-difficult to don -need pull sock or donning sleeve
-distal end discoloration
-very sensitive to volume fluctuations
USED FOR:
-most often at TH level, some TR
Anatomical suspension/self-suspending facts
socket encompasses bony prominences (humeral epicondyles) –> slide on and twist to self suspend
PROS:
-integrates with myoelectric control
-reduce or eliminate harnessing
CONS:
-difficult to don, push in or pull sock
-reduced ROM
LEVEL:
-transradial and wrist disarticulation
-can hybridize with suction
Types of UE power systems
-body power
-passive
-external power (motor)
Body power system facts
older tech
most common
individual generates the force necessary to cause movement –> usually though scapulothoracic bilaterally and glenohumeral joint ipsilaterally
body power an cable control operate together–> harnessing and cable system captures the force and excursion produced by other body movements and use it to operate the prosthesis
displacement and force of cable proportional to motion and force of scapulothoracic movements bilaterally and GH joint ipsilaterally
Force and excursion in relation to prosthesis
FORCE - strength or energy causing motion; strength of pull on cable
EXCURSION- movement from axis, distance traveled, translates to cable travel; larger ROM of scapulothoracic interface, the larger pull on the cable
Types of control systems for UE prostheses
cable control
myoelectric
hybrid
Shoulder disarticulation movements for force capture and excursion (what opens the terminal device)
-biscapular abduction
-scapular elevation
-chest expansion
transhumeral/elbow disarticulation movements to capture force and excursion
glenohumeral flexion
biscapular abduction
scapular depression/extension/abduction
transradial/wrist disarticulation movements for force capture and excursion (what opens the terminal device)
glenohumeral flexion
biscapular abduction
Passive prosthesis facts
-primarily cosmetic
CAN BE FUNCTIONAL:
-swivel shoulder
-locking elbow
-rotating wrist (supination and pronation)
-passive spring-loaded terminal device
-prepositioned with sound side (power is provided by the sound limb)
Externally powered prosthesis facts (power system)
power from on-board motor –> provides force for motion
can still be controlled by body
TD, wrist unit, and elbow each motorized and user-selected to function independently as determined by control strategy
-can be controlled myoelectrically.
Cable control system facts
Integrated with body power:
–harnessing to capture force and excursion through cable attached to harness
–proper harnessing is essential –> for proper control of cable
–analogous to bicycle brake lever or shifter
Integrated with External Power:
- harness connects to a linear transducer or switch
Myoelectric control system facts
*Most common control for externally powered prostheses (for motor powered UE prostehsis)
-electrodes imbedded in the socket wall for contact with skin
-Electrodes capture the electrical activity of a muscle contraction and convert it into a signal–> prosthetic hand function
-2 electrodes on antagonistic muscle groups
—-> co- contraction can allow you to switch between use of different muscle groups
-1 electrode on any viable site –> one selected movement, terminal device close; program opens when terminal device is relaxed
PROS:
-improved cosmesis
-increased grip force
-minimal to no harnessing
-ability to use overhead
-minimal effort to control
-control more closely corresponds to human physiologic control
CONS
-cost
-need of maintenance and repair
-fragile nature of gloves requiring frequent replacement
-less proprioceptive feedback than BP
-slowness in response
-increased weight
Hybrid control facts
A combination of cable control and myoelectric control
example: combination of body power cable control elbow with external power Miyo electric control terminal device for forearm
Terminal devices
replicates some or all of hand function that is lost
Grasp pattern types
-cylindrical
-hook or snap
-tip
-palmar
-spherical
-lateral
Voluntary open terminal devices facts
*Closure of the device is the default
-Force an excursion open, spring or rubber bands close
-pinch force is preset
-max pinch force when fully relaxed
Voluntary close terminal devices
-default the TD is fully open
-Force an excursion close, spring rubber bands open
-pinch force is determined by force exerted by user
Transradial considerations - case study in PPT
suspension
-harness or pin lock
power
-body powered
(more gross motor control)
control
-cable control
TD
-Voluntary open work hook or voluntary close heavy duty
Partial hand amputation considerations
use an opposition post to help grasp and hold onto items such as pen
WWI accelerated amputation_______-
rehabiltation
1960s
myoelectric arm created for first time
Congenital amputation types
transverse: absence of limb across its longitudinal axis
longitudinal: limb deficiency along the axis of the limb (such as radial or ulnar deficiencies)
-more common to have upper limb absences
Acquired amputation types
-traumatic (most for UE)
-dysvascular: necrotizing fasciitis, toxic shock, etc.
malignant: of bone/jont
Only__ of those with UE amputation choose to wear a prosthesis
50%
-majority of patients with UE acquired amputation are male and between ages of 21 and 64
Greifer hook
-quick handling and precise manipulation of small objects
-38 pound grasp and parallel gripping surfaces
AE amputation and body power vs electric
-less control of TD with body movement via the harnessing
-electric components may be more appropriate
Who should be referred to a Center for Excellence due to the complexity of the rehab process?
individuals with bilateral limb loss
esp those who wish to use myoelectric components
What can be used for muscle site control training for myoelectric prostheses?
biofeedback with use of phantom limb
practice antagonist motions and co-contraction of those motions
What is TMR used for?
Allows for the substitution muscle to serve as a myolelectric
control site for several motions at once
Used with myoelectric control, mainly for high BUE amputees
at this time
