Week 2 Flashcards
What is pathologic gait?
Impairment of an individual’s ability to walk
What is pathologic gait typically associated with?
Typically associated with altered mechanics and reduced efficiency
What mechanisms contribute to
pathologic gait?
- Impaired Motor Control
- Abnormal Range of Motion
- Impaired Sensation
- Pain
How can impaired motor control contribute to pathologic gait when impairments are of a peripheral origin?
There will be weakness
How can impaired motor control contribute to pathologic gait when impairments are of a central origin?
There will be: • Weakness • Hypertonicity • Lack of selective control • Apraxia • Ataxia • Rigidity
How does the clinical assessment of strength relate to walking ability?
• Walking ability commonly exaggerated by inability of strength tests to identify upper
levels of normal strength
• Strength grade of 3/5 – equivalent of single unilateral heel rise – required for normal gait although endurance likely
impaired
How can abnormal range of motion contribute to pathologic gait?
It can either be too little or too much
How can elastic contracture affect range of motion and gait?
- From inactivity or increased stiffness of bulky tissues
* Yield to forceful stretch
How can rigid contracture affect range of motion and gait?
- May arise from muscle shortness
- May be enhanced by scarring from trauma or surgery
- Resistant to considerable force
How might impaired sensation contribute to pathologic gait?
- Inconsistent gait pattern
- Prevents prompt substitution
- Includes perceptual deficits
How might pain contribute to pathologic gait?
- Slowed walking speed
- Shortened stance phase on the painful limb
- Tendency to stiffen the limb to avoid joint excursion
- Absence of forceful foot contact or push-off
How do primary impairments and compensatory actions relate: primary deviations?
Gait deviation occurring as a
direct result of a readily
associated impairment
How do primary impairments and compensatory actions relate: secondary deviations?
Gait deviation occurring as a secondary consequence of a more distant or obscure impairment. (THINK REGIONAL INTERDEPENDENCE)
How can we address pathologic gait clinically?
Problem Solving Approach
Problem Identification –> Cause Identification –> Treatment
How do we go about Problem
Identification?
Patient History + Physical
Examination + Observational
Gait Analysis
What is involved in Cause Identification?
• Consider possible causes of deviations observed • Determine likely causes based on results of impairment testing
What are the major deviations of the ankle to consider in gait analysis?
Excess Plantar Flexion • Foot Flat Contact • Forefoot Contact • Heel Off • Drag • Foot Slap Excess Dorsiflexion • No Heel Off
Why does excess plantar flexion arise in gait?
- Limitations in ankle DF ROM
- Pretibial muscle weakness
Depending on the phase of gait
Why does excess dorsi flexion arise in gait?
Calf muscle weakness
How does Excess Plantar Flexion affect Initial Contact?
- Foot Flat Contact
- Forefoot Contact
What does foot flat contact involve?
Initial contact by the entire plantar surface of the foot
What does forefoot contact involve?
Initial contact with the ground by the forefoot
What does Excess Plantar Flexion affect in Initial Contact?
The heel rocker mechanism, which progresses through loading response, limiting the forward momentum of the tibia and shock absorption
What is a heel off deviation?
When excess plantar flexion and forefoot only contact the ground and moves into stance, especially if it occurs throughout stance
____ might occur as an antalgic compensation for a painful heel during stance
Heel off deviation might occur as an antalgic compensation for a painful heel during stance
What does it mean when a heel off deviation occurs only later in stance?
It manifests as pre mature heel rise, it is more likely secondary to excess knee flexion as when knee extension ROM is very limited
What does heel off contribute to?
A smaller weightbearing surface, which leads to a reduced BOS and increased pressure on the metatarsal heads
What happens if the heel does contact the ground and Excess Plantar Flexion persist as a primary deviation due to limitations in ankle DF ROM or deficits in proprioception?
Knee hyperextension is likely to result, especially in mid stance and terminal stance
Excess PF in stance may occur as a secondary deviation in response to ____
Quad weakness
What are the consequences of Excess
Plantar Flexion in swing?
A drag
Why may excess PF persist in swing?
Due to pretibial muscle weakness or due to limitation in ankle DF ROM
What does drag most commonly involve when due to the persistence of excess PF?
Toe contact with the ground in mid or terminal swing, which may injure the toes or led to balance disruptions
What are the strategies used to avoid drag in compensating for a relatively long swing limb, as occurs with excess PF?
- Hiking of the pelvis
- Excess flexion of the hip
- Excess flexion of the knee
- Contralateral vaulting
What is Contralateral Vaulting?
Rising of the forefoot of the contralateral stance limb during swing limb advancement of the reference limb
What does contralateral vaulting lead to?
Increased demands of the PFs of the contralateral limb
In what phase of gait is excess PF due to a rigid contracture present and why?
All of them. Due to the fact that rigid contractures do not necessarily yield to external forces, including those generated by bodyweight and reactions with the ground
What should the interventions of excess PF due to a rigid contracture be focused on?
Improving ankle mobility, before improvements in the gait pattern can be expected
What will need to be addressed first in a patient who has excess PF due to a rigid contracture and pretibial weakness?
Mobility will need to be restored, before pretibial strengthening will be likely to reduce the occurrence of excess PF
In what phase of gait is excess PF due to an elastic contracture present and why?
Initial contact: Yes Loading response: yes/no Mid-stance: yes/no Terminal stance: yes/no Pre-swing: yes/no Initial swing: yes Mid- swing: yes Terminal swing: yes
Elastic contractures yield to varying degrees to the application of external forces. This is why they can be overcome in part during stance by bodyweight and ground reaction forces
What should the interventions of excess PF due to an elastic contracture be focused on?
Focused mobility or flexibility exercises are likely to result in changes of the gait pattern affected by an elastic contracture much more rapidly than an excess PF due to a rigid contracture
In what phase of gait is excess PF due to pretibial weakness present and why?
Initial contact: Yes Loading response: no Mid-stance: no Terminal stance: no Pre-swing: no Initial swing: yes Mid- swing: yes Terminal swing: yes
Appears only in the swing phase, leading into IC, because this is when the pretibial muscles are active in facilitating foot clearance
What should the interventions of excess PF due to pretibial weakness be focused on?
Pretibial strengthening
What is a foot slap?
A manifestation of pretibial muscle weakness, which involves uncontrolled PF at the ankle joint after heel contact. The sole of the foot rapidly comes in contact with the ground after IC. Only occurs if pretibial muscles are strong enough to provide heel first contact in Initial Contact (MMT: 3-/5)
What does a foot slap produce and how?
It produces shock absorption, by limiting knee flexion, while also reducing forward momentum of the tibia
How does Excess Dorsiflexion affect
stance/ weight acceptance?
It is secondary to excess hip or knee flexion, and serves to rapidly translate the body forward through loading response which reduce limb stability
What drives excess DF in single limb support?
Excess hip or knee flexion and inadequate extension of the toes
What is excess DF occurring as a primary deviation due to?
Calf muscle weakness, as weakened PFs are unable to restrain the forward advancement of the tibia, which may interfere with heel rise, leading to reduced progression over the forefoot and decreased step length in the contralateral limb
What is it referred to as when excess DF entirely disrupts normal heel rise in terminal stance?
No heel off
What does excess DF commonly lead to, regardless of when it occurs?
Increased demands on the hip and knee extensors, as efforts are made to maintain limb stability
Can No Heel Off affect the swing period
of gait?
Yes, especially when it is due to calf muscle weakness, it may result in limited knee
flexion which can limit limb clearance, leading to drag especially in Initial Swing
How does no heel off affect the swing period of gait when due to excess PF?
Drag more frequently occurs in mid or terminal swing.
How does no heel off affect the swing period of gait when due to limited knee flexion?
Drag more typically occurs in initial swing, because adequate knee flexion during initial swing is essential for adequate clearance of the foot
In what phase of gait does the greatest amount of knee flexion occur?
Initial swing
Inadequate knee flexion in initial swing may stem from ___
Inadequate PF occurring in terminal stance and pre- swing
What happens if the tibia is not pushed up under the femur, early in swing limb advancement?
Insufficient knee flexion may result and drag of the toes in initial swing may occur
What are the major deviations of the
foot to consider in gait analysis?
- Excess Inversion
* Excess Eversion
What are the major deviations of the
toes to consider in gait analysis?
- Inadequate Extension
* Clawed or Hammered Toes
How does Excess Inversion affect gait?
- Reduced shock absorption in Weight Acceptance
- Decreased limb stability in Single Limb Support
- Reduced clearance of foot in Swing Limb Advancement
How does Excess Eversion affect Swing Limb Advancement?
• May be caused by selective weakness of anterior tibialis or hypertonicity of peroneal muscles • Interferes with foot position for Initial Contact
In what population does excess foot inversion during gait mostly occurs?
In individuals with a neuromuscular dysfunction
What does excess foot inversion involve?
Greater than normal inversion of the rear foot for a specific phase of gait
What does excess foot eversion involve and what is it also known as?
Also known as excessive pronation. Involves greater than normal eversion of the rear foot for a specific phase of gait
What causes excess inversion of the foot?
May be caused by over activity of the inverters of foot, varus contracture, or variation in skeletal structural alignment, such as internal torsion of the tibia
What does excess inversion lead to?
A loss of foot function as a supple adapter in weight acceptance
How does excess eversion affect weight acceptance/ stance?
Leads to rotatory strain of the mid foot and knee
What are the causes of excess eversion in weight acceptance/ stance and in single limb support?
- Posterior tib muscle weakness
- Variations in muscle alignment such as rearfoot valgus deformities
- PF contracture (just in single limb support)
How does Excess Eversion affect Single
Limb Support?
- PF contracture leading to limitations in ankle DF ROM can be viewed as a driver for over pronation of the foot
- Increased DF of the oblique midtarsal joint, which promotes over pronation
- Interferes with the function of the midfoot and the fore foot as a rigid lever, which is essential for the function of the fore foot rocker
Where does the vector of pull of the anterior tibialis lie in reference to the subtalar joint axis?
Medial
Where does the vector of pull of the extensor digitorum longus lie in reference to the subtalar joint axis?
Lateral
What happens when the anterior tibialis is weak and extensor digitorum longus isn’t?
The foot is pulled laterally into eversion as active dorsiflexion is attempted during swing, which then interferes with foot positioning for initial contact
What does inadequate extension of the toes involve?
The occurrence of less metatarsal phalangeal extension than normal for a specific phase of gait.
How does Inadequate Extension of the
toes affect the gait pattern?
Not likely to interfere with weight acceptance, but does interfere with single limb support, especially terminal stance and swing limb advancement, particularly pre-swing
What causes inadequate extension of the
toes?
Limited metatarsal phalangeal joint extension ROM or toe flexor hypertonicity
What does inadequate extension of the
toes promote?
A loss of heel rise as a secondary deviation in terminal stance and especially in pre-swing
What does inadequate extension of the
toes interfere with?
Forward progression and decreased step length of the contralateral limb
What do clawed toes involve?
Flexion of the proximal and distal interphalangeal joints
What do hammered toes involve?
Flexion of the proximal interphalangeal joints and extension of the distal interphalangeal joints
What causes clawed/hammered toes?
Toe flexor or extensor hypertonicity or an imbalance of long toe extensors and intrinsic foot muscles
Clawed/hammered toes may occur in response to what?
Weak PFs, as the long toe flexors are used to compensate for the primary ankle PF weakness
How do Clawed or Hammered toes affect
Single Limb Support?
Interfere with single limb support, especially terminal stance and swing limb advancement, particularly pre-swing
What are the major deviations of the knee to consider in gait analysis?
- Limited Flexion/Hyperextension/Extension Thrust
- Excess Flexion/Contralateral Excess Flexion
- Varus
- Valgus
- Wobbling