Gait Deviations in Amputees Flashcards
What are the key goals of prosthetic alignment in gait assessment for amputees?
- Stability: Ensure proper GRF alignment to promote knee and hip stability during stance.
- Symmetry: Achieve equal weight distribution and balanced limb length for efficient gait.
- Mobility: Facilitate smooth transitions through all gait phases while supporting swing clearance.
- Comfort: Prevent pain or pressure points by optimizing socket fit and alignment.
- Energy Efficiency: Minimize compensatory movements and reduce energy expenditure during walking.
- Customization: Tailor alignment to the amputee’s functional level, strength, and confidence.
How should a dynamic gait assessment be performed for amputees?
Steps for a Dynamic Gait Assessment in Amputees
- Observation Sequence: Start at one joint and move systematically (e.g., from shoulders to trunk, pelvis, hips, knees, and feet).
- Assess both the prosthetic and sound limb.
- Views: Analyze gait from sagittal and frontal perspectives to identify deviations.
- Tools : Use slow-motion video analysis to capture subtle gait abnormalities.
- Identify Deviations: Look for asymmetry, uneven step length, trunk compensation, or knee instability.
- Determine Cause: Evaluate if deviations stem from prosthetic factors (alignment, fit, or components) or patient factors (weakness, contractures, or fear).
- Adjust and Reassess: Make necessary adjustments to prosthetic fit or alignment, and reassess to verify improvements.
- Goals:
- Normalize base of support.
- Equalize weight distribution, stride length, and stance time.
- Ensure stability, efficiency, and comfort.
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What are common causes of lateral trunk lean in amputees, and how can it be corrected?
- Causes of Lateral Trunk Lean in Amputees:
- Painful Residual Limb: Discomfort during stance phase leads to compensatory trunk lean toward the prosthetic side.
- Prosthesis Too Short: Creates an imbalance, causing the trunk to lean laterally.
- Weak Hip Abductors: Inability to stabilize the pelvis during midstance results in lateral lean.
- High Medial Wall: Discomfort from the prosthetic socket may lead to compensatory leaning.
- Poor Balance: Fear or inability to maintain upright posture contributes to trunk lean.
- Corrections for Lateral Trunk Lean:
- Address Residual Limb Pain: Ensure proper socket fit, adjust pressure points, and manage pain.
- Adjust Prosthesis Length: Ensure the prosthesis is appropriately aligned and not too short.
- Strengthen Hip Abductors: Prescribe targeted exercises (e.g., side-lying hip abduction) to improve stability.
- Modify Prosthetic Socket: Reduce medial wall height or improve fit to eliminate discomfort.
- Gait Training: Use verbal and tactile cues to correct the lean and improve dynamic balance
Explain exaggerated lumbar lordosis in amputee gait and its common causes.
Exaggerated Lumbar Lordosis in Amputee Gait: Excessive forward curvature of the lumbar spine during stance phase to compensate for pelvic or hip limitations.
- Common Causes:
Patient-Related Factors:
- Hip Flexion Contracture: Limited hip extension forces compensatory lumbar extension.
- Weak Hip Extensors: Insufficient gluteal strength leads to pelvic tilt for stabilization.
- Weak Abdominal Muscles: Reduced core support allows excessive lumbar extension.
- Anterior Pelvic Tilt: Habitual posture or compensation for weak muscles increases lordosis.
Prosthetic Factors:
- Insufficient Socket Flexion: Fails to accommodate natural hip flexion, requiring spinal compensation.
- Painful Ischial Weight Bearing: Discomfort in the socket causes a shift in posture to reduce pressure.
Corrections:
- Increase Socket Flexion: Align the prosthetic to allow proper hip extension without spinal compensation.
- Strengthen Hip Extensors: Target gluteal and core strengthening exercises to support pelvic alignment.
- Address Contractures: Implement stretching and mobilization to reduce hip flexion limitations.
- Optimize Socket Fit: Reduce pressure points and improve comfort for better posture control.
What causes hip hiking in amputees, and what corrections are recommended?
- Causes of Hip Hiking in Amputees:
- Prosthesis Too Long: Inadequate clearance during swing phase.
- Decreased Knee Flexion: Prosthesis restricts flexion or has excessive extension assist.
- Weak Hip Flexors: Insufficient strength to lift the limb for swing phase.
- Inadequate Suspension: Poor socket fit causes the prosthesis to feel too long.
- Fear of Catching Toe: Lack of confidence or improper gait training.
- Recommended Corrections:
- Adjust Prosthesis Length: Ensure appropriate alignment and length.
- Increase Knee Flexion: Modify knee settings to allow easier flexion.
- Strengthen Hip Flexors: Targeted exercises like marching and straight-leg raises.
- Improve Suspension: Reassess socket fit and add prosthetic socks if needed.
- Gait Training: Focus on improving swing mechanics and building confidence.
Describe pelvic drop and its common causes in amputee gait.
- Definition: Pelvic drop occurs when the pelvis on the prosthetic side dips during stance phase.
- Common Causes:
- Weak Hip Abductors: Insufficient strength to stabilize the pelvis during midstance.
- Poor Core Control: Lack of core strength or coordination.
- Improper Gait Training: Habit from single-limb hopping before prosthesis use.
- Socket Fit Issues: Inadequate medial-lateral support or poor suspension.
- Corrections:
- Strengthen hip abductors (e.g., side-lying leg lifts).
- Improve core stability through targeted exercises.
- Reassess socket alignment and fit for better pelvic support.
- Incorporate proper gait training with focus on equal weight distribution.
- Corrected by core strengthening and equal stance training.
- PhysioU
What causes limited hip extension in amputee gait, and how can it be managed?
Patient-Related Causes
- Hip Flexion Contracture: Tight hip flexors restrict full extension.
- Weak Gluteus Maximus: Insufficient strength to achieve proper hip extension during stance.
- Fear or Lack of Confidence: Patients may avoid full weight-bearing and forward progression on the prosthetic limb.
Prosthetic-Related Causes
- Socket Alignment: Insufficient flexion built into the socket limits natural extension.
- Prosthesis Length: Prosthesis too long discourages full extension due to clearance concerns.
Management Strategies
- Stretching and Mobilization: Perform stretches targeting hip flexors to reduce contractures.
- Strengthening Exercises: Strengthen gluteus maximus and other hip extensors through bridges, resisted hip extension, and step-ups.
- Gait Training: Focus on proper weight shifting and pelvic rotation to encourage hip extension.
- Prosthetic Adjustments: Reassess socket alignment and incorporate appropriate flexion angles; and ensure the prosthesis is of correct length to facilitate natural hip mechanics.
List possible causes of excessive knee flexion during stance phase.
Contracture, habit, pain, misaligned socket, weak quadriceps, excessive dorsiflexion.
Prosthetic Causes
Excessive Dorsiflexion of the Prosthetic Foot: Shifts the center of gravity forward, increasing knee flexion.
Stiff Heel Cushion or Too Firm Heel: Prevents smooth plantarflexion, causing the knee to flex more.
Socket Positioned Too Far Forward: Leads to an increased flexion moment at the knee.
Prosthetic Foot Too Far Posterior: Causes an exaggerated knee flexion moment during loading response.
Insufficient Plantarflexion in Prosthetic Foot Alignment: Reduces the ability to stabilize the knee during stance.
Knee Hyperextension causes
- BK = ?
- AK = ?
Below Knee (BK):
- Foot too far anterior in relation to socket
- Heel too soft
- Excessive socket flexion
- Too much plantar flexion in the foot
Above Knee (AK):
- Socket too far anterior
- Heel Too soft
- Insufficient socket flexion
- Hyperextension is a large risk for BK amputees due to the risk of ligamentous injuries/hypermobility.
- Hyperextension while not optimal is less of a risk especially with lower-level AK amputees because this makes them more stable.
What is knee instability in amputee gait, and how is it affected by prosthetic alignment?
- Knee Instability in Amputee Gait: Difficulty maintaining knee control during stance, leading to unintentional knee flexion or buckling.
Effects of Prosthetic Alignment on Knee Instability
- Socket Positioning:
- Too Far Anterior: Shifts GRF posterior to the knee, increasing knee flexion moments and instability.
- Too Far Posterior: Reduces flexion moments, promoting excessive extension and potential loss of mobility.
- Foot Placement:
- Too Far Posterior: Increases GRF behind the knee, promoting flexion and instability.
- Too Far Anterior: Shifts GRF anteriorly, promoting extension but reducing dynamic control.
- Ankle Angle:
- Excessive Dorsiflexion: Increases knee flexion moments, leading to instability.
- Excessive Plantarflexion: Encourages hyperextension but can reduce dynamic knee control.
- Heel Stiffness:
- Too Firm: Causes rapid flexion at heel strike, increasing instability risk.
- Too Soft: Promotes extension, which may stabilize but hinder mobility.
How do varus and valgus knee deviations present, and what causes them?
- Varus Knee Deviation: The knee shifts outward, creating a bow-legged appearance.
- Excessive Foot Inset: The prosthetic foot is positioned too medially.
- Socket Fit: Excessive medial-lateral dimensions or improper socket volume.
- Excessive External Rotation: Foot is rotated outward relative to the socket.
- Hypermobile Collateral Ligaments: Instability in the natural knee joint.
- Valgus Knee Deviation: The knee shifts inward, creating a knock-kneed appearance.
- Excessive Foot Outset: The prosthetic foot is positioned too laterally.
- Socket Fit: Excessive medial-lateral dimensions or improper socket volume.
- Excessive Internal Rotation: Foot is rotated inward relative to the socket.
- Hypermobile Collateral Ligaments: Instability leading to inward knee collapse.
Describe the impact of excessive plantarflexion on knee function during gait.
- Knee Extension Moments: Excessive plantarflexion shifts the GRF anterior, promoting knee hyperextension.
- Delayed Knee Flexion: Causes a “walking uphill sensation” by resisting forward progression in terminal stance.
- Swing Phase Impact: Limits knee flexion initiation, reducing swing phase efficiency.
- Injury Risk: Increases strain on ligaments and joint capsules, particularly in transtibial amputees.
- Causes: Foot in excessive plantarflexion, posteriorly positioned socket, soft heel, or long toe lever.
- Corrections: Adjust foot dorsiflexion angle, shorten toe lever, and ensure proper socket alignment.
How does excessive dorsiflexion affect knee biomechanics in amputee gait?
- Knee Flexion Moments: Excessive dorsiflexion shifts the GRF posterior, increasing knee flexion moments.
- Instability Risk: Amplifies knee instability, especially in early stance phase.
- Prosthetic Causes: Foot set in excessive dorsiflexion, anteriorly positioned socket, or stiff heel.
- Gait Impact: Challenges balance and increases muscular demands for knee control.
- Corrections: Adjust foot plantarflexion angle, reposition socket posteriorly, or use a softer heel.
