Prosthetic Gait Assessment & Common Deviations

What are factors influencing prosthetic gait?

1. Level of amputation

2. Technical capabilities of prosthesis

3. Strength of LE muscles

4. ROM of residual limb joints

How should prosthetic gait be analyzed?

- Optimal: treadmill if able

- Video lateral, anterior, and posterior views

For a transtibial prosthetic, what is normal gait during IC in the lateral view?

1. Ankle DF depends on type of foot/ankle

2. Ball of foot less than or equal to 4cm from floor

3. Knee slightly flexed

4. Pelvis and trunk erect

5. Smooth transfer of weight from intact leg (IL) to prosthetic leg (PF)

For a transtibial prosthetic, what is normal gait during LR in the lateral view?

1. Knee flexes less than normal (~10 degrees)

2. Prosthetic heel may compress

3. VIGOROUS QUADRICEPS CONTRACTION TO CONTROL KNEE FLEXION

What does normal transfemoral prosthetic gait look like?

Similar to normal transtibial (TT) gait

- Knee function and control depends on type of knee

- Microprocessor mimics intact knee

- If no microprocessor: knee extension from initial contact to mid stance

If there is NO microprocessor in the knee, what does the knee ROM look like from IC to MSt?

Knee extension

If there is microprocessor in the knee, what does the knee ROM look like from IC to MSt?

Slight knee flexion

What does normal MSt look like for TT/TF gait in anterior view?

1. Full weight on PL

2. Head or trunk sway toward PL side less than or equal to 2.5cm

3. Pylon (tube) is perpendicular to floor

4. Foot is flat

5. Slight lateral move of socket (due to femur adduction)

What does normal MSt look like for TT/TF gait in the lateral view with a dynamic foot?

- Longer foot flat

- Greater arc of DF

- Smoother transition than a SACH foot

What does normal MSt through PSw look like for TT/TF gait in the lateral view?

1. Full loading of PL to unloading PL and loading IL

2. Abrupt transition due to lack of active PF causes increased demand on IL

What does normal swing phase look like for TT/TF gait in anterior view?

1. Socket remains secure on limb

2. Shank and foot swing in the line of progression (as opposed to circumducting)

3. Pelvis remains level

What does normal swing phase look like for TT/TF gait in lateral view?

1. Knee intiall flexes easily and allows toe clearance, and then extends prior to heel contact

2. Socket remains secure on limb

3. Step length equal to other side

What are potential causes of gait deviations with prosthetics?

1. Improper fitting

2. Mal-alignment

3. Painful residual limb

4. Inadequate training

5. Motor memory/habitual pattern

What are potential consequences of gait deviations with prosthetics?

1. Increased energy consumption

2. Musculoskeletal injury

3. Limited functional outcomes

What are potential transtibial (TT) gait deviations?

1. Excessive knee extension

2. Knee instability

3. Vaulting or leaning

4. Drop-off

5. Excessive valgus

What are assessments made about excessive knee extension (TT gait deviation) from IC to MSt?

1. Best seen in lateral view

2. "Feels like I'm walking uphill."

3. May cause anterior distal RL pain

4. Pelvic displacement may appear as if PF is too long

What are potential causes of excessive knee extension from IC to MSt (TT)?

1. Posterior displacement of socket (anterior pylon); GRF moves anterior to knee axis from IC to FF

2. Insufficient socket flexion

3. Heel support is too soft (more common in SACH)

4. Inadequate training and lack of quad strength or confidence in knee control

What are assessments made about knee instability (TT gait deviation) from IC to TSt?

1. Best seen in lateral view

2. Often seen as A-P wobble at IC or TSt

3. "I'm afraid my knee will buckle", "It won't hold me"

4. Shortened stance phase

What are potential causes of knee instability from IC to MSt (TT)?

1. Toe lever arm is too short (anterior socket/posterior pylon)

2. Too much DF or too much socket flexion - those with traumatic amputations tolerate more than those with dysvascular amputations

What are assessments made about vaulting or leaning (TT gait deviation) from MSt to MSw?

1. Best observed from behind

2. Vaulting on IL (stance) or circumducting (swing)

3. Excessive knee flexion (swing)

OR

4. Excessive lateral shift (lumbar sidebending) toward PL side

5. "I am walking in a hole"

OR

6. Vaulting on PL

7. "I am walking uphill"

What are potential causes of vaulting or leaning from MSt to MSw (TT)?

1. Prosthesis is too long

2. Prosthesis is too short (some prefer this)

3. Long toe lever arm

What are assessments made about drop off (TT gait deviation) during TSt?

1. Knee appears to buckle in terminal stance

2. Downward movement of trunk in TSt

What are potential causes of drop off during TSt (TT)?

1. Short toe lever arm

2. Heel is too high

What are assessments made about excessive valgus (TT gait deviation) during TSt?

1. Best seen in AP view

2. Slight medial shift of knee at TSt (excessive pressure on head of fibual and distal tibia)

3. Confirm cause by testing for ligamentous laxity

What are potential causes of excessive valgus during TSt (TT)?

1. Inadequate medial offset of foot

2. Foot inversion

3. MCL insufficiency (lax)

What are potential transfemoral (TF) gait deviations?

1. Abducted gait

2. Excessive trunk extension/lordosis

3. Medial/lateral whip

4. Pistoning

What are assessments made about abducted gait (TF gait deviation) during MSt?

1. Best seen in AP view

2. Wide based gait (>5 cm)

3. PL never returns to midline

What are potential causes of abducted gait during MSt (TF)?

1. Prosthesis too long

2. High medial wall of prosthesis -- inadequate accommodation for ramus pressure

3. Abduction contracture

4. Inadequate gait training/poor habit

What are assessments made about excessive trunk extension/lordosis (TF gait deviation) during MSt-PSw?

1. Best seen in lateral view

2. Pt reports LBP or feeling like they are "not traveling far"

What are potential causes of excessive trunk extension/lordosis during MSt to PSw (TF)?

1. Insufficient initial socket flexion - increase lumbar ext to promote hip ext

2. Hip flexion contracture

3. Weak hip extensors/abdominals

What are assessments made about medial or lateral whips (TF gait deviation) during ISw?

1. Best seen from P view

2. Medial: heel tracks medially at beginning of initial swing

3. Lateral: heel tracks laterally at beginning of initial swing

What are potential causes of medial/lateral whips during ISw (TF)?

1. Medial = knee axis in excessive ER or prosthesis donned in ER

2. Lateral = knee axis in excessive IR or prosthesis donned in IR

3. Excessive soft tissue in residual limb with socket too tight

What are assessments made about pistoning/loss of suspension (TF gait deviation) during swing?

1. Prosthesis slips as foot leaves the ground

2. Toe catches on ground

3. Skin abrasions

What are potential causes of pistoning/loss of suspension during swing (TF)?

Suspension mechanism loose/inadequate

For a TT prosthetic, if you notice ball of foot > 4cm from the floor during IC, what should you check?

Check foot/ankle alignment

For a TT prosthetic, if you notice knee extension during IC, what should you check?

1. Socket:pylon

2. Socket flexion

3. Heel support

4. Strength/confidence

For a TT prosthetic, if you notice unequal step length during IC, what should you check?

Balance/training

For a TT prosthetic, if you notice knee instability from IC to LR, what should you check?

1. Socket:pylon

2. DF

3. Socket flexion

For a TT prosthetic, if you notice knee buckling from IC to LR, what should you check?

1. Same as instability

2. Strength

For a TT prosthetic, if you notice knee maintained in extension from IC to LR, what should you check?

See causes at IC

For a TT prosthetic, if you notice excessive leaning/lateral shift at mid-stance, what should you check?

1. Length of prosthesis

2. Fit of socket

3. Strength

For a TT prosthetic, if you notice no foot flat at mid-stance, what should you check?

Ankle/foot

For a TT prosthetic, if you notice drop-off at terminal stance, what should you check?

1. Socket:pylon

2. Heel height

For a TT prosthetic, if you notice excessive valgus at terminal stance, what should you check?

1. M/L offset of foot

2. Foot inversion

3. MCL insufficiency

For a TT prosthetic, if you notice vaulting during swing phase, what should you check?

Length of prosthesis

For a TF prosthetic, if you notice medial/lateral whip during swing, what should you check?

1. Knee axis rotation

2. Donning

For a TF prosthetic, if you notice abducted gait during mid stance, what should you check?

1. Medial socket brim

2. Ramus accommodation

3. Socket fit