Prosthetic Gait Deviations

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Prosthetic Gait Deviations

• Karyn Duff
• Prosthetist / Orthotist
• Hunter Prosthetics and Orthotics Service

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What is a gait deviation?

• Any gait characteristic that differs from the
  normal pattern
• Unsymmetrical gait
• Many possible causes
• Prosthetic
• Reduced ROM
• Muscle weakness
• Fear / Insecurity
• Habit

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Prosthetic Alignment

• Correct alignment of the prosthesis allows
• Optimal gait
• Optimal pressure distribution across stump
• Optimal stability
• Optimal control
• Reduces energy expenditure
• Three steps to prosthetic alignment
• Bench alignment
• Static alignment
• Dynamic alignment

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Bench alignment Trans tibial

• Sagittal Plane
• Heel height matches patients shoe
• Socket 5 flexed
• Weight line
• Centre of lateral socket
• Posterior 1/3 of foot

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Bench alignment Trans tibial

• Frontal Plane
• Abduction / Adduction to match patient
• Weight line
• Centre of posterior socket
• Centre of heel (or up to 10mm laterally)
• Transverse Plane
• 5-10 toe out

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Bench alignment Trans femoral

• Heel height matches patients shoe
• Socket 5 flexed
• Weight line
• Centre of lateral socket
• 5-15mm anterior to knee centre
• Posterior 1/3 or foot
• Length may be up to 10mm shorter than sound side

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• Common Prosthetic Gait Deviations

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Rotation of prosthetic foot at IC

• Description
• Prosthetic foot externally rotates at Initial
  Contact
• Causes
• Too hard a heel
• Too hard a plantarflexion bumper
• Socket too loose

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Foot slap

• Description
• Foot progresses too quickly from heel strike to
  foot flat, creating a slapping noise
• Causes
• Heel too soft
• Plantarflexion bumper too soft
• Excessive socket flexion
• Excessive dorsiflexion
• Poor knee extension control

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Excessive knee flexion (at IC)

• Description
• Knee flexes excessively at I.C
• Patient feels like hes walking downhill
• Causes
• Heel cushion too hard
• Excessive dorsiflexion of prosthetic foot
• Foot too posterior in relation to socket
• Excessive flexion built into socket

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Lateral Trunk Bending

• Description
• Trunk bends towards amputated side during
  prosthetic stance phase
• Causes
• Short prosthesis
• Pain on lateral distal aspect of stump
• Abducted socket
• Low lateral wall of socket
• Weak hip abductors
• Short stump

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Medio-lateral knee thrust

• Description
• Knee shifts medially or laterally during
  prosthetic stance phase
• Causes
• Foot placed too medially (lateral thrust)
• Foot placed too laterally (medial thrust)
• ML dimension of proximal socket too large

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Abducted gait

• Description
• Walking base significantly larger than normal
  range of 50-100mm
• Causes
• Prosthesis too long
• Too small socket
• Insufficient suspension
• Locked knee
• Abducted socket
• Pain in groin area
• Fear / Insecurity
• Contracted hip abductors

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Absent or insufficient knee flexion

• Description
• Insufficient knee flexion at I.C and / or knee
  hyperextension at T.S
• Patient may report pressure on distal tibia
• Patient feels like hes walking uphill
• Causes
• Excessive plantarflexion of prosthetic foot
• Heel too soft
• Too soft a plantarflexion bumper
• Insufficient socket flexion
• Foot too anterior in relation to socket

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Circumduction

• Description
• Prosthesis follows a lateral curved line as it
  swings through
• Causes
• Prosthesis too long
• Locked knee
• Inadequate suspension
• Too small a socket
• Foot set in plantarflexion
• Lack of knee flexion (fear / insecurity of
  patient)

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Vaulting

• Description
• Amputee bobs up and down excessively as he walks.
  He raises his entire body by plantar-flexing the
  sound foot.
• Causes
• Prosthesis too long
• Inadequate suspension
• Locked knee
• Socket too small
• Foot set in plantarflexion
• Lack of knee flexion (fear / insecurity of
  patient)

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Uneven Timing

• Description
• Steps are of uneven duration or length, usually a
  short stance phase on the prosthetic side
• Causes
• Poorly fitting socket causing pain
• Fear / insecurity
• Poor balance
• Weak stump musculature

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Instability of prosthetic knee

• Description
• The prosthetic knee has a tendency to buckle on
  weight bearing
• Causes
• Incorrect alignment of prosthesis (weight line
  passes behind knee centre creating flexion
  moment)
• Weak hip extensor muscles
• Severe hip flexion contracture

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Terminal swing impact

• Description
• The prosthetic shank comes to a sudden stop with
  a visible or audible impact
• Causes
• Insufficient knee friction
• Extension assist too great
• Habit of forceful knee flexion
• Fear of knee buckling at I.C

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Increased Lumbar Lordosis

• Description
• Lumbar lordosis is exaggerated during prosthetic
  stance phase
• Causes
• Insufficient AP socket support
• Insufficient socket flexion
• Pain on ischial tuberosity area
• Hip flexion contracture
• Weak hip extensors or abdominals

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Swing Phase Whips

• Description
• At toe off heel moves laterally (lateral whip) or
  medially (medial whip)
• Causes
• Inadequate suspension
• Knee internally rotated (lateral whip)
• Knee externally rotated (medial whip)

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Uneven heel rise

• Description
• Prosthetic heel rise does not match sound side.
• Causes
• Inadequate knee friction (high heel rise)
• Inadequate extension assist (high heel raise)

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Excessive forward flexion

• Description
• During stance patient excessively leans forward
• Causes
• Unstable knee joint
• Hip flexion contracture
• Too short gait aids

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• Any Questions???