Gait Deviations in Individuals with Lower Limb Amputations

Original Editor - Abby Cain as part of the World Physiotherapy Network for Amputee Rehabilitation Project

Top Contributors - Jess Bell, Admin, Shaimaa Eldib, Kalyani Yajnanarayan, Naomi O'Reilly, Kim Jackson, Tarina van der Stockt, Tony Lowe and Ewa Jaraczewska

Introduction

When assessing the gait of individuals with amputations, it is important to understand the gait cycle, common features of prosthetic gait, and the link between gait deviations and function. Individuals with amputation often develop certain gait deviations to compensate for, or adapt to, prosthetic and personal factors. It is important to identify these deviations and the resultant functional changes to ensure appropriate rehabilitation interventions.

Gait Cycle

The gait cycle has two phases, stance phase and swing phase. Stance phase makes up 60% of the gait cycle. Some part of the foot is in contact with the ground during stance phase. This creates a closed chain environment and introduces ground reaction forces. Swing phase makes up 40% of the gait cycle. The foot is not in contact with the ground during the swing phase of gait.

If you would like to read more about the gait cycle, please see:

• The Gait Cycle
• Normal Gait, which includes a range of videos of ankle, knee, hip, pelvic and trunk movements during gait

Body Functions During Gait

There are five key body functions during gait, which can be remembered using the acronym BEEPS. In individuals with amputation, these functions can be compromised by the prosthetic device or physiological limitations (described in the next section):

• B = balance and stability
  • a stable standing posture is necessary for walking
• E = energy conservation
  • energy consumption is increased in individuals with lower-limb amputation vs those without amputation
• E = equality and symmetry
  • individuals with lower-limb amputation often have asymmetrical gait patterns, particularly in unilateral and transfemoral amputation
• P = forward progression
  • during gait, the centre of mass moves forward continuously
• S = shock absorption
  • various mechanisms reduce forces on the joints during gait

When body functions are compromised, individuals with amputation might experience secondary medical conditions, such as osteoarthritis, back pain and pressure injuries. The goal of rehabilitation is to focus on restoring or improving body functions.

Causes of Gait Deviations in Individuals with Amputations

Gait deviations in individuals with lower-limb amputations can have patient / physiological causes and prosthetic causes.

Patient / physiological causes can include muscle weakness, contracture, pain, the length of the residual limb, pressure wounds, sheer injuries or other potential injuries to the skin, decreased confidence in the prosthesis or residual limb and habitual or learned behaviours.

Prosthetic causes can include the type of prosthetic, prosthetic malalignment and a poor-fitting prosthetic socket.

Gait Assessment Forms

The Gait Assessment and Intervention Toolbox (G.A.I.T) can be used to assist with your gait analysis. The Comprehensive G.A.I.T and Quick G.A.I.T forms are available from Enability.

When using this tool, you analyse both the intact and the amputated limb to identify specific deviations at each joint (from the foot to the trunk) during each phase of gait. The G.A.I.T form also includes temporal-spatial gait deviations, such as step length, step width, etc. Finally, it includes an "Intervention Focus" section that highlights which of the five functions of gait (BEEPS) should be targeted in rehabilitation.

Using this form can help remove the guesswork from observational gait analysis -- Vibhor Agrawal

Common Gait Deviations in Individuals with Lower-Limb Amputations

Using the Comprehensive G.A.I.T or Quick G.A.I.T can help to simplify your gait assessment. The following tables provide further information on some of the common gait deviations in individuals with lower-limb amputations and their potential causes. They also include videos of different gait deviations to help with your gait analysis.

These tables are not exhaustive and they focus on the prosthetic limb. As highlighted in the G.A.I.T form, gait analysis should also consider the intact limb. Some of the potential causes relate to the prosthesis and others to the individual. Understanding these causes can help guide the overall rehabilitation plan.

Remember, it is important to link the deviation with specific gait functions. This functional emphasis changes the focus of rehabilitation from correcting specific gait deviations to helping individuals with amputations achieve and optimise gait functions.

Transtibial Gait Deviations

Table 1. Transtibial gait deviations in the prosthetic limb

Deviation	Description	Potential causes	Illustration
Absent/reduced knee flexion	The knee does not flex as expected during loading response or it hyperextends The patient may report it feels like they are walking up a hill	Faulty suspension of the prosthesis The socket is set in too much extension or too far posteriorly Heel cushion is hard Too much flexion damping (i.e. too much resistance to knee flexion) in the prosthetic knee Too much plantar flexion at the ankle Weak quadriceps Reduced confidence or ability to control prosthetic knee flexion mechanisms Poor trunk or hip alignment
Excessive knee flexion	Increased knee flexion at heel strike / midstance, the patient may report that it feels like their knee is unstable or as if they are walking downhill	Faulty suspension of the prosthesis Socket is set in too much flexion or too far anteriorly Too much dorsiflexion at the ankle Heel cushion is too firm Inadequate flexion damping in the prosthetic knee Flexion contracture of the knee or hamstring tightness Eccentric weakness of quadriceps
Foot external rotation	External rotation of the prosthetic foot at heel strike	The prosthetic heel is too hard The socket is loose Weak hip extensors Reduced push-off on the intact limb
Knee instability	Slow progression through stance phase Knee flexion is ‘jerky’ or 'hesitant' during heel strike to foot flat	Weak quadriceps Deconditioning Too much dorsiflexion or anterior translation of the socket over the foot
Excessive lateral or medial thrust of the prosthesis (valgus/varus moment)	The knee shifts laterally or medially during prosthetic stance phase	Lateral thrust: foot is placed medially (inset) in relation to the socket quadriceps weakness Medial thrust: foot is placed laterally (outset) in relation to the socket hip abductor weakness Socket is loose (for both medial and lateral thrust)
Drop off (early knee flexion)	Heel off occurs too early causing early knee flexion	The foot is positioned too far back (posterior) in relation to the socket Excessive dorsiflexion of the foot Keel or toe lever arm is too soft or too short Shoe heel height is too high
Knee hyperextension (or delayed knee flexion)	Heel off is delayed, potentially causing hyperextension of the knee Patient might report it feels like they are walking uphill	The foot is set too far forward (anterior) in relation to the socket Excessive plantar flexion of the foot Heel cushion is too soft Keel or toe lever arm is too firm or too long
Pistoning	The tibia moves vertically during the weight bearing and non-weight bearing periods of gait	Loose or inadequate suspension Socket is too large Socket is faulty

Transfemoral Gait Deviations

Table 2. Transfemoral gait deviations in the prosthetic limb

Deviation	Description	Potential causes	Illustration
Prosthetic knee instability	The prosthetic knee has a tendency to buckle on weight bearing	Knee is set too far anteriorly Heel bumper is too firm Hip extensor weakness Socket is not sufficiently flexed to match the degree of contraction
Foot slap	The foot progresses too quickly from heel strike to foot flat, creating an audible slapping noise	Lack of plantar flexion resistance in the prosthetic foot The individual forces foot contact to gain knee stability Plantar flexion bumpers are excessively soft Excessive dorsiflexion
Abducted gait	Increased base of support during gait The prosthetic foot is placed more laterally	There is pain / pressure on the ramus or lateral distal femur Medial brim of the socket is too high Prosthesis is too long Weakness Contracture There is space in the lateral wall of the socket Fear / lack of confidence when transferring weight onto the prosthesis
Lateral trunk bending	Trunk leans towards the prosthesis during prosthetic stance phase	The prosthesis is too short Short residual limb Abduction of the socket (especially when the residual limb is short) There is space in the socket Weakness / contracture of hip abductors There is pain / pressure on the ramus or lateral distal femur Foot is excessively outset Lack of balance Habit
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 extensors and abdominal muscles Lack of support from the anterior wall of the socket Insufficient socket flexion Habit
Whip (lateral or medial)	During swing phase (observed at or just after toe-off), the foot ‘whips’ laterally or medially	Poor suspension Socket internally or externally rotated Incorrect donning of the prosthesis Loose socket
Pistoning	The femur moves vertically during the weight bearing and non-weight bearing periods of gait	Insufficient suspension Socket is too loose / doesn't fit well
Excessive heel rise	Prosthetic heel rises more than the heel on the intact limb	Inadequate resistance to knee flexion
Circumduction	The limb swings out to the side in a wide arc during swing phase on the prosthesis side	The prosthesis is too long The ankle is set in too much plantar flexion Hip flexor weakness Incorrect activation pattern, with excessive use of the hip abductors to initiate swing Lack of confidence or ability to initiate swing and enable appropriate knee flexion Issues with the brim of the socket Poor suspension, which causes the prosthesis to slip Extension assist is too strong Knee flexion resistance is extreme
Vaulting	The individual rises onto the toe of the intact limb during swing phase on the prosthetic limb to help achieve foot clearance	The prosthesis is too long Increased mechanical resistance to knee flexion Loose suspension - the prosthesis drops off (effectively lengthening) during swing phase
Excessive terminal impact	Forcible impact as the knee goes into extension at the end of terminal swing, just before heel strike	Inadequate resistance to knee extension Lack of friction of knee flexion / mechanical function of the prosthetic knee Extension aid is too strong Habit - the individual deliberately snaps their knee into extension with excessive force to ensure extension is achieved

Transfemoral and Transtibial Gait Deviations

Table 3. Transfemoral and transtibial amputation gait deviations

Deviation	Description	Potential causes	Illustration
Uneven step length	Steps are of uneven duration or length, usually with a short stance phase on the prosthetic side	Often associated with increased lumbar lordosis Insufficient socket flexion Fixed flexion deformity at the knee Hip flexion contracture Pain leading to decreased weight bearing on the prosthetic side Fear Poor balance Painful, poorly fitting socket
Uneven arm swing (secondary deviation)	The arm on the prosthetic side is held close to the body	Poor prosthetic fit Poor balance Fear Habit Associated with other gait deviations and a lack of gait rehabilitation

Resources

• Enability, Practice Videos - Prosthetics
• Amputee Gait Deviations Playlist