Gait deviations in transfemoral prosthetics can result from various factors related to both the patient and the prosthesis. Common patient-related causes include muscle weakness, contractures, pain, decreased confidence in the prosthesis, or habitual behaviors. Prosthetic causes often involve malalignment or poor-fitting sockets1.
Transfemoral amputees typically exhibit a more asymmetric gait compared to transtibial amputees. The level of amputation and the type of prosthesis significantly influence the gait pattern, affecting both performance and adaptation. For instance, the selection of suspension type in the prosthesis can impact stability and, consequently, gait deviation2.
It’s important to assess and address these deviations as they can lead to other complications such as increased energy expenditure during walking, joint stress, and discomfort. Rehabilitation efforts should focus on correcting these deviations through proper prosthetic fit, alignment, and training to improve the patient’s gait and overall mobility
2. Introduction
• While assessing amputee gait it is important to be aware of
normal gait and how normal gait in the amputee is affected.
• Furthermore, there may be deviations which an amputee will
adopt to compensate for the prosthesis, muscle weakness or
tightening, lack of balance and fear. These deviations create an
altered gait pattern and it is important that these are recognized,
as rehabilitation of the gait will need to encompass corrections
of these deviations
3. 1. Instability of the prosthetic knee
Description:
The prosthetic knee tends to flex during
the prosthetic stance phase, creating a
danger of falling.
When to observe:
During stance phase
How to observe:
From the side
4. Causes:
1. The knee joint may be too close to, or anterior to the Trochanter-Knee-
Ankle
(TKA) line.
2. The socket may have been aligned in too little flexion.
3. There may be too much plantarflexion resistance (prosthetic heel or
plantarflexion bumper are too hard) , causing the knee to flex at heel
strike.
4. If the foot is set in dorsiflexion or the foot is too small, leading to
incomplete
knee control.
5. The amputee’s hip extensors may be weak, and they are unable to
provide
adequate force to control the knee.
6. The amputee may have a severe hip flexion contracture, which has not
5. 2. Medial/Lateral Whip
Description:
A medial whip occurs at toe-off when
the heel moves to the inside (medially)
as the knee begins to bend.
A lateral whip occurs at toe-off when
the heel moves to the outside
(laterally) as the knee begins to bend.
When to observe:
At or just after toe-off
How to observe:
From behind the amputee
6. Causes:
1. Medial whip is caused when the knee
axis has too much external rotation.
2. Lateral whip is caused when the knee
axis has too much internal rotation.
3. The socket may be too tight or have not
enough space to accommodate
muscles. Pressure from contracting
muscles then causes the prosthesis to
rotate around its long axis.
4. The toe break may not be set at the
correct angle to the line of progression.
5. The stump may have weak, loose
musculature, in which tissues rotate
freely around the femur.
8. Causes:
Circumduction is often a patient response to a prosthesis that is too long, or behaving
in a way that makes it too long. This causes the amputee to swing the prosthesis
out to the side to clear the foot (such as:)
1. Manual knee lock, too much friction, or a tight extension aid may prevent the
knee from bending.
2. Inadequate suspension may allow the prosthesis to slip off the stump (piston
action).
3. The socket is too small/tight. The ischial tuberosity is above the ischial
seat.
4. The foot is set in plantarflexion.
5. The prosthesis is actually too long. Other reasons for circumduction can be:
6. The amputee uses little or no knee flexion because of insecurity or fear.
7. Habit
8. Discomfort in the perineal area.
9. 4. Vaulting:
Description:
The amputee’s center of gravity moves
up
and down excessively The entire body is
raised by excessive plantarflexion of the
sound foot. You can observe that the
normal foot is raised onto the toes while
walking.
When to observe:
During sound leg stance phase
How to observe:
From behind the amputee or from the
side
10. Causes:
1. Vaulting is a patient response to a prosthesis which is too long, or behaving
in a way that makes it too long, (such as) The amputee vaults so that the foot
will
clear the ground in mid swing
• Inadequate suspension allows the prosthesis to slip off the stump (piston
action).
• Manual knee lock, too much friction, or a tight extension aid may prevent the
knee from bending.
• The socket is too small/tight. The ischial tuberosity is above the ischial seat.
• The foot is set in plantarflexion.
• The amputee uses little or no knee flexion because of insecurity or fear.
• The prosthesis is actually too long.
• Habit – the patient may have walked in this manner for a long time.
11. CONTD…..
2. There is not enough control of heel rise in early swing phase
(friction / pneumatic / hydraulic resistance). In normal gait,
maximum elevation of the body occurs when the supporting limb
is in the middle of stance phase and the other limb swings
alongside it. When there is not enough control of heel rise in
early swing phase the shank takes a
longer time to swing forward. Because of this time lag, the body
is no longer at maximum elevation as the prosthetic foot is at its
lowest point in swing through. The prosthetic foot would fail to
clear the
ground unless the amputee gained additional time and clearance
by vaulting.
12. 5. Abducted Gait:
Description:
The width of the walking base is much
greater than the normal range of 50-100
mm. There is usually exaggerated lateral
displacement of the pelvis and lateral
bending of the trunk. You will observe
that
the prosthesis is always put out to the
side
while walking.
When to observe:
During the period of double support
How to observe:
From behind the patient
13. Causes:
1. The prosthesis behaves like it is too long. The amputee walks with an
abducted gait so that the prosthesis will clear the ground during swing
phase. This could be due to one of the causes
2. The shank is aligned in a valgus position in relation to the thigh
section.
3. There is pain or discomfort in the crotch area. The discomfort may be
caused by factors such as skin
infection, adductor roll, or pressure from the brim of the medial socket
wall. The amputee tries to gain relief by abducting the prosthesis, thus
moving the medial brim away from the painful area.
4. The mechanical hip joint may be set so that the socket and stump are
brought
into abduction.
5. The abductors of the hip may be contracted.
6. The amputee may feel insecure, and may compensate by widening
the
walking base. listed under Circumduction.
14. 6. Lumbar Lordosis
Description:
The normal convexity of the lumbar
area is
exaggerated when the prosthesis is
in
stance phase.
When to observe:
Throughout stance phase
How to observe:
From the side
15. Causes:
1. There is a flexion contracture of the hip. A flexion contracture aggravates
the tendency of the pelvis to tilt anteriorly because the shortened hip flexor
muscles pull on the pelvis and lumbar spine when the hip moves into extension.
The amputee throws his or
her shoulders back to compensate for the forward tilt of the pelvis, and to maintain
stability.
2. The socket has been aligned in too little flexion.
3. There is not enough support from the brim of the anterior socket wall. This
allows the pelvis to rotate anteriorly and pulls the lumbar spine into lordosis.
4. The patient’s hip extensors are weak. The extensors help to restrain the
tendency of the pelvis to tilt forward. When this restraining force is lost, the
resulting forward tilt of the pelvis and compensatory backward bending of the trunk
causes increased lordosis. In addition, the amputee may roll the pelvis forward to
assist the weak extensors to control stability of the prosthetic knee.
16. CONTD….
5. The patient’s abdominal muscles are weak. The abdominal
muscles usually restrain the tendency of the pelvis to tilt forward.
When the abdominal muscles are weak, some of this restraint is
lost and the amputee will show increased lordosis.
6. Weight-bearing on the ischium may be painful. The amputee
may roll the pelvis forward to relieve pressure on the ischium.
17. 7. Lateral bending of the trunk
Description:
The patient leans the body towards the
prosthetic side when the prosthesis is in
stance phase. This movement shifts the
patient’s center of gravity towards the
prosthesis.
When to observe:
From just after heel strike to mid-stance
How to observe:
From behind the patient
18. 1. The prosthesis is too short.
2. The lateral wall of the socket does not
provide enough support. If there is not
enough support to block lateral
movement of the femur, the pelvis will
tend to drop on the sound side when the
prosthesis is in stance phase. To correct
this, the amputee leans towards the
prosthetic side.
3. The socket is abducted. This
alignment fault reduces the effectiveness
of the hip abductors in stabilizing the
pelvis. The pelvis will tend to drop on the
sound side, and the amputee will try to
correct this by leaning towards the
prosthetic side.
4. The lateral distal part of the stump is
painful or uncomfortable and the
amputee tries to relieve pressure on it
by leaning towards the prosthetic side.
5. The amputee’s abductors are weak. As
above, lateral bending corrects the
tendency towards pelvic drop on the
sound side.
6. Lateral bending of the trunk usually
occurs when an amputee walks with an
abducted gait. The same factors that
cause abducted gait may also cause
lateral bending.
Causes:
19. 7. Rotation of the foot on heel strike
Description:
As the heel contacts the
ground, the foot
rotates laterally, sometimes with
a
vibratory motion.
When to observe:
At heel strike
How to observe:
From in front of the patient
20. Causes:
1. The plantarflexion bumper or heel
cushion is too hard.
2. If the patient has a new suction
socket,
foot rotation may be due to poor
control of the socket by the stump.
3. The patient may be correcting his
or
her gait after a lateral whip
21. 8. Terminal swing Impact
Description:
The prosthetic shank comes to a sudden
stop with strong impact as the knee goes
into extension. You may hear a noise
when
the prosthesis is fully extended.
When to observe:
At the end of swing phase
How to observe:
From the side
22. Causes:
1. There is not enough friction /
pneumatic / hydraulic control on the
prosthetic knee.
2. There is too much tension on the
extension aid.
3. The amputee’s fear of knee flexion
causes him/her to sharply extend the
stump as the knee approaches full
extension. This movement snaps the
shank forward into full extension and
then “digs” the heel into the ground.
23. 8. Drop-off
Description:
At the end of stance phase, as the
body
moves forward over the prosthesis
there is
a downward movement of the trunk.
When to observe:
At the end of stance phase
How to observe:
From the side
24. Causes:
1. There may not be enough restriction
of
dorsiflexion of the prosthetic foot. (The
dorsi-flexion bumper is too soft, the
foot is too small, the foot is broken)
2. The keel of the SACH foot may be
too
short, or the toe break of a
conventional foot may be too far
posterior.
3. The socket may have been placed
too
25. 9. Uneven heel rise
Description:
The prosthetic heel rises higher
than the
sound heel, OR the prosthetic heel
shows a
smaller rise than the sound heel.
When to observe:
During initial swing phase
How to observe:
From the side
26. Causes:
Too much heel rise may be
caused by:
1. Not enough control (friction /
pneumatic / hydraulic) on the
prosthetic knee.
2. No extension aid, or not enough
tension in the extension aid.
3. The patient forcefully flexing the
stump to ensure that the
prosthetic shank will be fully
extended at heel
strike.
Too little heel rise may be
caused by:
1. Too much control (friction /
pneumatic/ hydraulic) on the
prosthetic knee.
2. The extension aid being too
tight.
3. Fear and insecurity, as the
amputee walks with little or no
knee flexion.
4. Manual knee lock.
27. 10. Uneven timing
Description:
The steps are of unequal
duration. There is
usually a very short stance
phase on the
prosthetic side.
When to observe:
Throughout the gait cycle
How to observe:
From the side
28. Causes:
1. The socket may not fit properly. To
avoid pain, the amputee may try to
shorten the stance phase on the
prosthetic side.
2. Alignment stability may be a factor, if
the knee flexes too easily.
3. The amputee may not have developed
good balance.
4. The patient may have weak muscles.
5. Fear and insecurity may contribute to
this problem.