Exam 5: Prosthetics TransTib ReadGuide/Lecture/Handout/Video, Transtib Gait Deviations

Question 1

What is the suggested way to use the following Gait deviation cards when you study?

Answer 1

Try to think through the possiblities to come up with your answers instead of just memorize lists.

Question 2

Transtib gait deviation Causes: Initial Contact to Loading Response

• Hyperextension moment of the knee
  
  • Amputee (2)
  • Prosthesis (5)

Try to think of the rationale with each one; there are too many for me to go into the rationale for each, but please investigate further until you understand)

Answer 2

Amputee:

1. weak quads (rationale: pt compensates by forcing into hyperextension)
2. Too forceful quad contraction

Prosthesis:

1. Too soft or too low a heel cushion
2. Too low a shoe heel
3. Posterior leaning pylon
4. Foot too anterior = short heel lever
5. Foot too plantarflexed

Question 3

Transtib gait deviation Causes: Initial Contact to Loading Response

• Flexion moment of the knee
  
  • Amputee (2)
  • Prosthesis (6)

Try to think of the rationale with each one; there are too many for me to go into the rationale for each, but please investigate further until you understand)

Answer 3

Amputee

• Unaccommodated knee flexion contracture
• Weak quads

Prosthesis

1. Too hard a heel cushion
2. too high a shoe heel
3. Anterior leaning pylon (flexed socket > 5-15 degrees)
4. Foot too posterior = long heel lever
5. Foot too dorsiflexed
6. Excessive pressure against distal, anterior tibia (possible rationale: because it hurts the pt bends knee quickly to accomodate)

Question 4

Transtib gait deviation Causes: Initial Contact to Loading Response

• External rotation of the prosthesis
  
  • Amputee (1)
  • Prosthesis (2)

Try to think of the rationale with each one; there are too many for me to go into the rationale for each, but please investigate further until you understand

Answer 4

Amputee

• weak internal rotators

Prosthesis

• Too hard or too high a heel cushion
• Too much toe out

Question 5

Transtib gait deviation Causes: Mid-stance

• Abducted Gait
  
  • Amputee (1)
  • Prosthesis (1.5)

Try to think of the rationale with each one; there are too many for me to go into the rationale for each, but please investigate further until you understand

Answer 5

Amputee

• Habit

Prosthesis

• Pylon too long
• (outset foot may mimic this)

Question 6

Transtib gait deviation Causes: Mid-stance

• Trunk Leaning
  
  • Amputee (1)
  • Prosthesis (4)

Try to think of the rationale with each one; there are too many for me to go into the rationale for each, but please investigate further until you understand

Answer 6

Amputee

• Weak abductors (lean towards the side of weak standing side)

Prosthesis

• Too short or too long
• Outset foot (probably lean towards to get weight over foot)
• Improper socket fit causing pain (lean away from it to avoid pain?)
• Medial leaning pylon (probably lean towards in order to get weight over foot) - similar to outset foot

Question 7

Transtib gait deviation Causes: Mid-stance

• Valgus moment at knee
  
  • Amputee (1)
  • Prosthesis (1)

Try to think of the rationale with each one; there are too many for me to go into the rationale for each, but please investigate further until you understand

Answer 7

Amputee

• none

Prosthesis

• outset foot
• (wouldn’t medially leaning pylon also cause this?)

Question 8

Transtib gait deviation Causes: Mid-stance

• Varus moment at knee
  
  • Amputee (1)
  • Prosthesis (1)

Try to think of the rationale with each one; there are too many for me to go into the rationale for each, but please investigate further until you understand

Answer 8

Amputee

• none

prosthesis

• inset foot
• (wouldn’t laterally leaning pylon also cause this?)

Question 9

Transtib gait deviation Causes: Mid-stance

• Walking on lateral border of foot
  
  • Amputee (1)
  • Prosthesis (1)

Try to think of the rationale with each one; there are too many for me to go into the rationale for each, but please investigate further until you understand

Answer 9

Amputee

• none

Prosthesis

• laterally leaning pylon

Question 10

Transtib gait deviation Causes: Mid-stance

• Walking on medial border of foot
  
  • Amputee (1)
  • Prosthesis (1)

Try to think of the rationale with each one; there are too many for me to go into the rationale for each, but please investigate further until you understand

Answer 10

Amputee

• none

prosthesis

• medially leaning pylon

Question 11

Transtib gait deviation Causes: Mid-stance

• Decreased Stance time
  
  • Amputee (2)
  • Prosthesis (1)

Try to think of the rationale with each one; there are too many for me to go into the rationale for each, but please investigate further until you understand

Answer 11

Amputee

• Inadequate weight bearing
• Poor balance

Prosthesis

• pain from socket

Question 12

Transtib gait deviation Causes: Mid-stance

• Trendelenburg Gait
  
  • Amputee (2)
  • Prosthesis (1)

Try to think of the rationale with each one; there are too many for me to go into the rationale for each, but please investigate further until you understand

Answer 12

Amputee

• weak hip abductors
• Poor balance

Prosthesis

• none

Question 13

Transtib gait deviation Causes: Terminal Stance to Pre-Swing

• Drop-Off (knee bending too early, rolling over toe rocker too early/fast)
  
  • Amputee (1)
  • Prosthesis (3)

Try to think of the rationale with each one; there are too many for me to go into the rationale for each, but please investigate further until you understand

Answer 13

Amputee

• habit

Prosthesis

1. Toe lever too short
   
   • foot too posterior
   • Keel too short
2. Excessive socket flexion
3. Excessive dorsiflexion

Question 14

True/False: The ideal leg length for a prosthetic leg varies between shorter, longer, or the same length as the sound side?

Answer 14

False

ideally both legs should be the same length,

(but amputee comfort and functional ambulation must be considered in determining final socket alignment)

Question 15

What is “drop off?”

Answer 15

During ambulation, pt loses support for the body weight prematurely, causing the knee to flex and the hip to drop sharply before the end of the stance. This deviation is called drop-off.

Usually caused by a short toe lever arm

Question 16

Transtib gait deviation Causes: Terminal Stance to Pre-Swing

• Delayed knee flexion
  
  • Amputee (2)
  • Prosthesis (2)

Try to think of the rationale with each one; there are too many for me to go into the rationale for each, but please investigate further until you understand

Answer 16

Amputee

• Poor Pelvic Control (I think leaving ASIS back too far instead of rotating it forward on the horizontal plane)
• Weak knee flexors

Prosthesis

• Foot too anterior
• Excessive Plantar flexion

Question 17

Transtib gait deviation Causes: Initial Swing to Terminal Swing

• Shortened prosthetic stride length (short swing)
  
  • Amputee (1)
  • Prosthesis (3)

Try to think of the rationale with each one; there are too many for me to go into the rationale for each, but please investigate further until you understand

Answer 17

Amputee

• Knee flexion contracture

Prosthesis

1. anterior leaning pylon
2. Pylon too short
3. Inadequate suspension

Question 18

Transtib gait deviation Causes: Initial Swing to Terminal Swing

• Inabillity to clear the floor
  
  • Amputee (1)
  • Prosthesis (2)

Try to think of the rationale with each one; there are too many for me to go into the rationale for each, but please investigate further until you understand

Answer 18

Amputee

• none

Prosthesis

• Prosthesis too long
• INadequate suspension

Question 19

Transtib gait deviation Causes: Initial Swing to Terminal Swing

• Vaulting
  
  • Amputee (2)
  • Prosthesis (3)

Try to think of the rationale with each one; there are too many for me to go into the rationale for each, but please investigate further until you understand

Answer 19

Amputee

• Habit or fear of catching toe
• Improper gait training for initiation of hip flexion

Prosthesis

1. Prosthesis too long
2. Inadequate suspension
3. Excessive plantar flexion

Question 20

Transtib gait deviation Causes: Initial Swing to Terminal Swing

• Lateral Whip
  
  • Amputee (1)
  • Prosthesis (1)

Try to think of the rationale with each one; there are too many for me to go into the rationale for each, but please investigate further until you understand

Answer 20

Amputee

• Improperly donned (Rotated)

Prosthesis

• Internally rotated socket

Question 21

True/False: Some individuals prefer a slight shortening of the prosthetic leg to enhance prosthetic swing.

What should we think of this?

Answer 21

True

ideally both legs should be the same length, but amputee comfort and functional ambulation must be considered in determining final socket alignment

Question 22

Transtib gait deviation Causes: Initial Swing to Terminal Swing

• Medial Whip
  
  • Amputee (1)
  • Prosthesis (1)

Try to think of the rationale with each one; there are too many for me to go into the rationale for each, but please investigate further until you understand

Answer 22

Amputee

• Improperly donned (rotated)

Prosthesis

• Externally rotated socket

Question 23

Transtib gait deviation Causes: Initial Swing to Terminal Swing

• Pistoning
  
  • Amputee (1)
  • Prosthesis (2)

Try to think of the rationale with each one; there are too many for me to go into the rationale for each, but please investigate further until you understand

Answer 23

Amputee

• None

Prosthesis

• Socket Too Loose
• Improperly donned

Question 24

TransTib Gait Deviations Video:

Gait Deviations may be due to (5)

Answer 24

1. Improperly Fitted Socket
2. Malaligned Prosthesis
3. Improperly functioning foot
4. Painful Residual Limb
5. Poor Walking Habits (only one that is amputee problem)

Question 25

TransTib Gait Deviations Video:

Person wearing a PTB socket with Cuff suspension may have a slight _____ thrust of the knee at the ________ rim of the socket during midstance.

Is this a problem?

Answer 25

Person wearing a PTB socket with Cuff suspension

• may exhibit a slight lateral thrust of the knee at the proximal rim of the socket during midstance
• As long as this is slight and does not affect comfort or stability, there is no need for concern

Question 26

TransTib Gait Deviations Video:

describe a Well Aligned Prosthesis (sagittal and frontal veiws)

Answer 26

• Saggital Veiw:
  
  • plumb line dropped from the center of the socket rim at the patellar tendon level should pass no more than 1.5 inches ahead (anterior) of the center of the pylon. This will allow the amputee to have support throughout the stance phase, and be able to roll over his foot in a smooth manner.
• Frontal View:
  
  • Foot is set ½ inch medial to a line dropped from the center of the posterior wall

Question 27

TransTib Gait Deviations Video:

What happens if socket is placed too far anterior over the foot? (mechanically plus 3 points about gait deviations it could cause)

Answer 27

• Toe lever arm will be shortened

1. pt will not be supported in the terminal stance phase
2. pt loses support for the body weight prematurely, causing the knee to flex and the hip to drop sharply before the end of the stance. This deviation is called drop-off.
3. can see it causing shorter stance phase on prosthetic side

Question 28

TransTib Gait Deviations Video:

What happens if socket is placed too far posteriorally over the foot? (mechanically plus 5 points about gait)

Answer 28

• Toe lever arm will be increased, and the heel lever arm will be decreased
  
  1. The pt’s center of gravity moves anterior to the axis of rotation of the knee very fast, forcing the knee into hyperextension.
  2. Pt will feel as if he is walking uphill as the length of anterior support is increased
  3. when too long a toe lever arm occurs, the patient tends to have the knee in extension throughout midstance
  4. also causes some degree of pelvic displacement
  5. it sometimes looks as if the pt is walking with a prosthesis that is too long

Question 29

TransTib Gait Deviations Video:

What about an uneven step gait? (4)

• What happens?
• Why does this happen?
• Prosthesis or amputee cause?

Answer 29

1. Pts who have not developed confidence in their ability to use a prosthesis try to reduce the amount of time they spend on the prosthesis, taking a short step with the non-amputated leg, and a long step with the prosthesis.
2. This gait pattern, which is often the result of inadequate gait training, uses an inordinate amount of energy, and can be prevented by a thorough gait training program. It is very difficult to alter if allowed to persist.
3. There is no prosthetic cause for uneven steps per se.
4. If the prosthesis is uncomfortable, the pt will show a similar pattern

Question 30

TransTib Gait Deviations Video:

What if Prosthetic Leg is longer than the sound leg? (4 points)

Answer 30

• Pt will use excess energy to raise center of mass (COM) over the support point
• Best seen in the anterior posterior view, and can be seen in the hips and shoulders
• Pt may have some difficulty in bringing the prosthesis forward in swing
  
  • must flex knee excessively or vault
• He looks like he is leaning laterally towards prosthesis in stance and away in swing (very minor, not mentioned in video)

Question 31

TransTib Gait Deviations Video:

What determines the density of a prosthetic foot (I assume they are referring to a SACH-like foot)?

Answer 31

Density of prosthetic foot is determined by the size and weight of the amputee.

Question 32

TransTib Gait Deviations Video:

What if the prosthetic leg is shorter than the sound leg? (7 points)

Answer 32

1. Person will seem to be walking in a hole on one side
2. The shoulder on the amputated side will drop at the beginning of stance phase
3. There is great excursion of the center of mass (COM) leading to excess energy expenditure
4. Jarring of the residual limb caused by the dropping on the amputated side can lead to abrasions
5. Some individuals prefer a slight shortening of the prosthetic leg to enhance prosthetic swing.
   
   1. ideally both legs should be the same length, but amputee comfort and functional ambulation must be considered in determining final socket alignment
6. He looks like he is leaning towards short side (prosthetic side) during stance

Question 33

TransTib Gait Deviations Video:

What will happen if the foot is shifted too far laterally (too far outset)? (6 points)

Answer 33

Foot set too far lateral (to far outset)

1. pt will lose support medially during stance phase
2. Trunk will bend laterally to try to reach the support point
3. Pt will feel excess pressure at the proximal lateral rim of the socket and the medial end of the residual limb.
4. Gait base will be quite wide
5. Can be best seen in the anterior Posterior plane
6. Note particularly the movement of the trunk and shoulders

Question 34

TransTib Gait Deviations Video:

What will happen if the foot is shifted too far medially (too far inset)? (6 points)

Answer 34

Foot set too far Medial (too far inset)

1. Lateral support is missing in single foot stance phase
2. Pt will tend to compensate by leaning laterally (doesn’t say which way, but it looks like towards the prosthetic side even though this doesn’t make a lot of sense to me)
3. Pt will experience excessive pressure at the proximal medial and lateral distal part of the residual limb
4. There will also be excessive lateral displacement of the socket away from the residual limb, which may cause injury to the knee joint
5. Watch particularly the knee during stance phase
6. narrow support base (narrow based gait)

Question 35

TransTib Gait Deviations Video:

What will happen with a lateral leaning pylon (and what is a laterally leaning pylon)? (definition plus 6 points)

Answer 35

Lateral Leaning Pylon (top of pylon is more lateral than bottom)

1. Pt will walk with narrow based gait
2. pt will walk on lateral border of shoe
3. There will be increased pressure at the medial proximal rim of the socket
4. Pt will exhibit gait similar to a pt with the foot too far inset
5. In both instances, the support base is narrowed and there is excessive lateral motion of the knee during stance.
6. When this gait type is observed, you can determine the cause by looking at the pylon in a posterior plane at midstance.

Question 36

TransTib Gait Deviations Video:

What will happen with a medial leaning pylon (and what is a medeally leaning pylon)? (definition plus 8 points)

Answer 36

Medial Leaning Pylon (top of pylon is more medial than bottom)

1. Pt will walk with wide base
2. Pt will walk on medial border of shoe
3. There will be increased pressure at the lateral rim of the socket
4. The smoothness of the gait pattern will be altered
5. Similar in appearance to a gait with the foot too far outset
6. Shoulder on the amputated side dips laterally during stance
7. When this gait is observed, you can determine the cause by looking at the pylon in a posterior plane at midstance
8. An apparent medial leaning pylong may sometimes be noted when the person does not shift his weight properly over the prosthesis
   
   • This can be differentiated by an actual medially leaning pylon by watching the hip at midstance.

Question 37

TransTib Gait Deviations Video:

What will happen if the prosthesis has too hard a heel [cushion]? (5 ish points)

Answer 37

Too Hard A Heel (cushion)

1. The necessary amount of PF and shock absorption will not take place
2. The knee on the prosthetic side may be forced into excessive flexion from heel contact to midstance
3. Knee instability and buckling may result
   
   • the pt will then try maintain knee stability by extending the knee against flexing forces, thereby creating excessive pressure at the anterior distal end of the residual limb and possibly the posterior proximal rim
4. Excessive anterior distal pressure can lead to abrasions and skin breakdowns on the residual limb
5. watch the knee on the amputated side, particularly at midstance

Question 38

TransTib Gait Deviations Video:

What will happen if the prosthesis has too soft a heel [cushion]? (3-4 points)

Answer 38

Too Soft a Heel (cushion)

1. Pt will walk with a gait similar to someone with too long a toe lever arm
2. the heel cushion compresses excessively and the pt feels as if he is walking up a hill
3. As a result, he will try to keep the knee extended during stance
   
   • the anterior rim of the socket may impinge on the patella, causing pain and abrasions

Question 39

TransTib Gait Deviations Video:

Conclusion/Summary statement

Answer 39

The efforts that go into careful prosthetic fabrication, fit, check-out, and thorough gait training, result in a well-fitting prosthesis that enables the amputee to walk comfortably and easily. In the finished prosthesis, the pt should be able to walk comfortably with minimal amount of energy expenditure for all normal activities.

Question 40

Gait Deviations you may see IC to LR (3)

Answer 40

1. hyperextension moment at knee
2. flexion moment of the knee
3. external rotation of the prosthesis

Question 41

Gait Deviations you may see at mid-stance (8)

Answer 41

1. abducted gait
2. trunk leaning
3. valgus moment at knee
4. varus moment at knee
5. walking on lateral border of foot
6. walking on medial border of foot
7. decreased stance time
8. trendellenburg

Question 42

Gait Deviations you may see at terminal stance to pre-swing (2)

Answer 42

• drop off
• delayed knee flexion

Question 43

Gait deviations you may see initial swing to terminal swing (6)

Answer 43

1. shortened prosthetic stride length (short swing)
2. inability to clear the floor
3. vaulting
4. lateral whip
5. medial whip
6. pistoning