Gait deviations in amputees
While assessing amputee gait it is important to be aware of normal gait and how normal gait in the amputee is affected. You can learn about this on the Gait in prosthetic rehabilitation page.
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 recognised, as rehabilitation of the gait will need to encompass corrections of these deviations.
Gait deviations in lower limb amputees can be broadly broken into the patient and the prosthetic causes:
- Patient Causes:
- Muscle weakness
- Decreased confidence in the prosthesis or residual limb
- Habitual/learned behaviours
- Prosthetic Causes:
- Prosthetic malalignment
- Poor-fitting prosthetic socket
Important things to note about the gait of people with lower-limb amputations:
- Gait patterns are different than age-matched people without an amputation
- "Transtibial and transfemoral amputees show a common and specific gait pattern"
- Transfemoral amputees have a more asymmetric gait than transtibial amputees
- The level of the amputation and the type of prosthesis affect gait, for e.g. in transfemoral amputees, the type of prosthesis will influence the gait pattern of the same person, in both performance and adaptation. 
The trunk and lower limb gait:
- Someone with a lower limb amputation can have altered trunk motion during functional tasks
- Increased trunk flexion and trunk velocity can be some of the risks associated with falling for this population.
- Assessment and rehab should include not only trunk-pelvis, core, and hip abductor strength but also focus on training of the placement of the prosthetic knee and foot to help modify trunk movement during gait. 
Common deviations are listed in the tables below:
|Absent/inadequate knee flexion||Knee fully extended at heel strike||
Faulty suspension of the prosthesis - too soft heel cushion or plantar flexor bumpers
Foot placement too far forward on stepping
Lack of pre-flexion of the socket
|Excessive Knee Flexion|| Increased knee flexion at heel strike (or mid stance), the patient feels as though walking downhill
Faulty suspension of the prosthesis
Prosthetic foot set in too much dorsiflexion
Stiff heel cushion
Flexion contracture of the knee
Foot too posterior in relation to the socket
|External Rotation of Foot at Heel Strike||External rotation of the prosthesis/foot at heel strike.||
heel to hard
|Knee instability||Knee flexion ‘jerky’ in the presentation during heel strike to foot flat||Weak Quadriceps|
|Valgus/Varus Moment|| Knee shifts medially or laterally during prosthetic stance phase
Foot placement (medial placement causes lateral thrust and vice versa)
Foot alignment on the prosthesis
|Drop Off||Heel off occurs too early causing early knee flexion||
Foot too posterior on the prosthesis in relation to the socket
Excessive dorsiflexion of the foot on the prosthesis
Soft heel bumper on the prosthesis.
|Knee Hyperextension||Delayed heel causing hyperextension of the knee, walking uphill sensation||
Foot set too far forward on the prosthesis in relation to the socket
Too hard a heel cushion
Too much plantar flexion on the foot.
|Whip||During swing phase foot ‘whips’ laterally or medially||
Knee internally or externally rotated
|Pistoning||Amputee drops into the socket as the foot moves into flat foot, tibia moves vertically during alternately weight bearing and non-weight bearing periods of gait||
Lack of prosthetic socks
Suspension loose or inadequate
Too large or faulty socket
Transfemoral Gait Deviations:
|Prosthetic Instability|| The prosthetic knee has a tendency to buckle on weight bearing
Knee set too far anterior
Heel cushion too firm
Weak hip extensors
The heel of the shoe too high causing the pylon of the prosthesis to move anteriorly
Severe hip flexion contracture
|Foot Slap|| Foot progresses too quickly from heel strike to foot flat, creating a slapping noise
Patient forcing foot contact to gain knee stability
Heel cushion too soft
Plantar flexion cushion too soft
|Abducted Gait||Increased base of support during mobility, prosthetic foot placement is lateral to the normal foot placement during the gait cycle.||
Prosthesis too long
Socket too small
Suspension belt may be insufficient-band may be too far from the ileum
Pain in the groin or medial wall of the prosthesis
Hip abductor contractures
Lateral wall of the prosthesis not supporting the femur sufficiently
The socket of prosthesis abducted in alignment
Fear/lack of confidence transferring weight onto prosthesis
Alignment of the lower half of the pylon of the prosthesis in relation to socket.
|Lateral Trunk Bending||Trunk flexes towards prosthesis during prosthetic stance phase||
Prosthesis too short
Short stump length
Weak or contracted hip abductors
Foot outset excessively in relation to socket
Lack of prosthetic lateral wall support
Pain on the lateral distal end of the stump
Lack of balance
|Anterior Trunk Bending||Trunk flexes forwards during prosthetic stance phase|
|Increased Lumbar Lordosis|| Lumbar lordosis is exaggerated during prosthetic stance phase
Poor shaping of the posterior wall of the prosthesis or pain on ischial weight bearing, resulting in anterior pelvic rotation
Flexion contracture at the hip
Weak hip extensor
Poor abdominal muscles
Lack of support from the anterior wall of the socket
Insufficient socket flexion.
|Whip (during swing phase)|| At toe-off heel moves laterally (lateral whip) or medially (medial whip)
Prosthetic knee alignment
Incorrect donning of the prosthesis i.e. applied internally rotated or externally rotated weakness around the femur
Prosthetic too tight.
|Pistoning||Socket dropping off when prosthesis lifted||
Socket too loose or delayed knee flexion during toe off (‘free knee only’) caused by increased resistance of the prosthesis
Alignment of prosthesis
|Excessive Heel Rise||Prosthetic heel rises more than sound side||
Lack of friction on prosthetic knee
Amputee generating more force than required to gain knee flexion
Poor/lack of extension aid
|Reduced Heel Rise|| Prosthetic heel does not rise as much as sound side
Lack of hip flexion
Too much friction on free knee
Extension aid to tight
|Circumduction||Lateral curvature of the swing phase of prosthesis||
Prosthesis too long
Fixed knee and poor hip hitching
Poor suspension causing prosthesis to slip
Excessive plantar flexion of the foot
Weak hip flexors
Socket too small
Insufficient knee flexion.
|Vaulting||Amputee rises onto the toe of the non-prosthetic limb during the prosthetic swing phase||
Prosthesis too long
Fear of catching the toe of the prosthesis on the floor
Insufficient knee flexion (free knee) due to decreased confidence
Lack of ‘hip hitching’ with a ‘locked/fixed knee’
Poor suspension prosthesis-slips off during swing phase
Socket too small
Excessive friction on knee flexion of the prosthesis.
|Terminal Impact||Forcible impact as the knee goes into extension at end of terminal swing phase, just before heel strike||
Lack of friction of knee flexion
Extension aid too excessive
Absent extension bumper
Amputee deliberately snaps knee into extension by excessive force to ensure extension.
Steps are of uneven duration or length, usually a short stance phase on the prosthetic side
|Uneven Step Length||Steps are of uneven duration or length, usually a short stance phase on the prosthetic side||
Fixed flexion deformity at the knee
Insufficient friction of prosthetic knee creating an increased step length on prosthetic side,
Hip flexion contracture
Pain leading to decreased weight bearing on the prosthetic side
Painful poorly fitting socket
|Uneven Arm Swing (secondary deviation)||The arm on the prosthetic side is held close to the body||
Poor prosthetic fit
Always due to other gait deviations and lack of training
This is not an exhaustive list and the deviation described for each level of amputation is not exclusive to that level, but is more likely to occur for that amputation.
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