Flashcards in Prosthetics Deck (32):
What is a Syme's disarticulation?
- heel pad preserved and attached to end of tibia for WB
Can you weight bear through disarticulations?
T/F: Selective loading is made in a prosthetic socket through build ups on tendon-bearing areas.
- relief for bony prominences, nerves, tendons
What is the terminal device in a lower-extremity prosthetic?
the foot (terminal end that interacts with environment)
What motions does a SACH foot limit?
limits sagittal plane motion, specifically PF
- allows small ML motion, transverse motion
For a similar foot to the SACH foot but for a more active individual, what would you prescribe?
a SAFE foot: solid ankle flexible endoskeleton
- allows more nonsagittal plan motions
What motions does a single-axis foot allow?
sagittal plane motion, with stops
Where are sensitive pressure areas of a transtibial amputee?
anterior tibial crest
fibular head and neck
What are areas that can tolerate pressure in a trans-tibal amputee?
medial tibial plateau
Which type of friction would an older adult who is mostly sedentary need for their knee prosthetic?
(vs variable friction, used for varying speeds for more active individuals)
If the knee center is set too far forward from the TKA line, what will happen at the knee?
knee will be unstable and buckle
What does a friction brake in the knee do?
increases friction at midstance to prevent knee flexion, but allows smooth knee motions through rest of gait cycle
What is an extension aid in a prosthetic limb?
external elastic strap or internal coiled sprong that assists with TKE during late swing
Where is pressure directed in an above-knee prosthetic?
lateral sides of residual limb
distal end (can be sensitive though)
Why would a patient demonstrate bending towards the prosthetic side during gait?
- shorter prosthetic limb
- hip pain
- weak abductors
- low lateral wall, high medial wall
T/F: A long prosthesis may result in an abducted stance.
T/F: A socket being too big might cause a patient to vault on the other side to bring the prosthetic limb forward.
false: socket to small can cause vaulting, not too big
What might cause excessive lumbar lordosis during stance with a prosthetic?
- painful ischial WB
- hip flexion contracture
- weak hip extensors or abs
- insufficient support from anterior or posterior walls
- inadequate socket flexion
Why might the knee lock into TKE during terminal swing with a prosthetic?
- pt fearful so excessively hip flexes limb
- insufficient knee friction
- too much tension in knee extension aid
Why might there be a heel whip with a prosthetic limb during swing?
excessive rotation in prosthetic
knee bolt rotated
T/F: A patient who favors the sound limb and limits weight bearing time on the prosthetic limb with demonstrate decreased step length on the prosthetic side.
False, shorter step length on sound side since they won't stay long on the prosthetic limb in stance
With a medial thrust in midstance for a TTA, what could potentially be wrong with the prosthesis?
laterally placed foot
T/F: A socket being set too far backward can cause premature knee flexion in stance.
false, socket too far forward = premature knee flexion
T/F: If the socket for a TTA is aligned to far backward or tilted posteriorly, this can result in inadequate knee flexion.
A patient reports that they feel like they're walking uphill with their prosthetic limb. What could be happening?
socket set too far back/lacks sufficient flexion
DF bumper is too stiff causing excess PF
prosthetic foot keel too long
An unstable knee unit will result in what gait deviation?
forward flexion during stance
Inadequate socket flexion will result in what gait deviation?
excessive lordosis during stance
What prosthetic causes can result in a circumducted gait?
locked knee unit
loose knee friction
inadequate socket suspension
With a plantar flexion bumper being too soft, what gait deviation can occur?
- can also occur if heel cushion is too soft`
What could cause a lateral thrust in mid stance from a prosthetic?
foot inset too medially
What can cause premature knee flexion in late stance?
DF bumper too soft
socket set too far forward/excessively flexed
prosthetic foot keel too short