What type of socket is this and

what is the purpose for it?

[image][image]

Quad Socket

• Has a small (tight) A/P dimension & a large (wide) Medial Lateral dimension
• It provides ischial placemnt on the brim for ischial WB

What type of socket is this and

what works best about it?

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Narrow Meidal Latearl (Ischial containment) Socket

• It is used to improve the mechanics of gait by matching the contour of the anatomy
• Provides WB
• The ischium fits inside the socket by a bony lock around the ischial ramal complex

• Skeletal stability is dependent upon tight M/L control

• Suction - most common
• Silesian Belt - used more on active individuals (is a bit bulky)
• TES Belt
• Partial Suction w/ belt -does not create perfect suction
• Hip joint & pelvic band
• Supracondylar
• Pin Lock - typically used on midlength amputees (the residual limb must be short enough to accomadate the pin lock)
• Lanyard - a strap that feeds out of the bottom of the socket and velcro's into place

There residual limb is not at

 a stable state yet, it will still be shrinking

1. [image]2. [image]3. [image]

4. [image]5. [image]

Suspension Systems for Transfibial Amputees

1. Suction
2. Pelvic and Hip Belt
3. Lanyard
4. Lanyard Kiss system
5. Tes Belt

What are the three main goals

for a transfemoral amputee?

1. Mediolateral femoral stabilization
2. Maintain Knee extension throughout stance phase
3. Take a normal sound side step length

What is this picture representative of for a transfemoral amputee?

[image]

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Pelvic instability at midstance (trendeleberg gait)

often due to lack of M/L femoral stabilization

This could be related to a short residual limb

What action occurs at the

hip during gait for a transfemoral amputee?

(this action could cause lateral lean)

How is this issue corrected?

• the hip abductors contract resulting in femur abduction (creating a varus moment and lateral lean - this is more of an issue when the limb is very short -- close to a hip disarticulation)
• To Correct
  • set the socket at 9 - 11 degrees of adduction and contour the lateral wall of the socket
  • Provide a narrow M/L socket with a boney lock on the ischial tuberosity and ramus (provides greater control)

• Limb length (longer limb = much better control)
• Adducted socket
• Strong muscles
• Smooth lateral wall within the socket
• Joint integrity
• Boney lock

What are the rules to maintaining knee extension for a transfemoral amputee?

FRL = floor reaction line???

• Keep the mechanical knee posterior to the Weight line (FRL)
  • If the FRL is posterior to the knee to flex and buckle
• Set the knee with stability, but not excessive stability

• The prosthesis will be unstable, the knee will flex and buckle
• To correct
  • Train the amputee to utilize hip ext to create a knee ext moment
  • Get the foot flat quickly then progress to PF rapidly, to mechanically create more of an extension moment

Normal Step Length

• In Normal Human Locomotion (NHL) the ankle is placed _____ degrees posterior to the verticle line from the hip
• When the ankle and knee motion are lost ____ degrees are lost at the hip

• 15 degrees NHL
• 7 degrees lost for an amputee

In order to take a normal sound side step lenght it has got to come from the hip joint:

• An able bodied person presents with _____ degrees at the hip and ______ degrees at the knee and ankle, and _____ degrees for pelvic lordosis.
• An amputee will have ____ degrees of pelvic lordosis and ____ degree at the hip.
• To make up for this loss how many degree of flexion are set in the hip socket to allow for max extension of the hip?

• Abled bodied person
  • 5 degrees at the hip
  • 7 degrees at the knee and ankle
  • 3 degrees of pelvic lordosis
• Amputee
  • 10 degrees pelvic lordosis
  • 5 degrees at the hip
• Set the socket with 5 degrees of flexion for max extensoin

Knee Units

• Single Axis
• Polycentric
• Friction
  • Constant friction vs variable friction
• Extension Assist
• Weight activated
• Mauch
• MPK

• Single Axis - one pivot point (cost effective)
• Polycentric - contains multiple centers of rotatoin that move
  • increases stability - enhances TKA (trochanter/knee/ankle) alighment
•  Friction - regulates speed
  • Constant friction - has one speed only
  • Variable friction (for an active amputee)
    • Simulates NHL
    • It is cadence responsive to and increase or decrease in resistance
    • The mechanism is fluid (hydraulic or phuematic)
•  Extension Assist - used when there is a lack of quad control, helps with swing phase control
• Weight Activated - provides stance control, locks into place when weight is placed on it (good for geriatrics)
• Mauch - hydraulic controlled
• MPK - microprocessor controlled knee

Knee Units 

1. [image]

2. [image]3. [image]

4. [image]5. [image]6. [image]

1. polycentric
2. friction
3. extension assist
4. weight activated
5. mauch
6. MPK - microprocessor controlled knee

early stance from heel strike to foot flat

to correct: teach patient to fire hip extensor to create an extension moment to prevent buckling and falling

What are some of the main points to

work with an above the knee amputee

on in pre-ambulatory training?

• Lateral weight shift (side to side)
• Anterior/Posterior weight shift - shift of wt from heels to keels
• Forward lateral stance phase control - splitting feet apart, have them step out w/ prosthesis first and work kon swing control (learn to use the hip to clear the prosthesis from the ground)
• Work on taking a normal stride length with the sound limb
• Do constant repetition of each pre-amb training
• Get the patient to look forward, not down