Abnormal Mobility Flashcards
Disorders of ____ are one of the earliest and most characteristic symptoms of a wide variety of neurologic conditions.
gait
What is the most debilitating consequence of neurologic pathology?
Limitations in gait that result in restricted participation in the mobility domain
What do mobility disabilities cause?
reduced performance on functional activities
e.g., walking on different terrains, up/down stairs or curbs, while carrying objects or simply walking, and overall ADLs
What 2 levels of the ICF model does mobility affect?
activities and participation
What is the objective/importance of classifying gait disorders?
To arrange individuals into homogenous groups to assist clinicians with communication and clinical decision-making regarding intervention
And essentially to enhance “Subject Selection” and improve “internal validity” in clinical studies
What can gait disorders be classified according to?
Neurologic diagnosis
What are a few neurologic diagnoses that have specific gait patterns?
- Parkinsonian gait
- Cerebellar ataxic gait
- Spastic hemiparasis gait
- Hemiplegia or diplegia gait
What is an alternative classification of gait patterns?
Pathophysiologic mechanisms and main impairments
What are the 4 components of motor system impairments that play a role in gait disorders?
- paretic component
- spastic component
- cocontraction component
- nonneural component
Defective muscle activation is associated with what component?
paretic
Define paresis
loss of adequate force generation in muscles
Paresis is due to what 2 things?
- deficient recruitment of motor units, and secondary changes in the muscle fibers
- altered number, type, and firing rate of motor neurons essential for force generation
Paresis/Weakness can result in what?
- inability to generate adequate forces to move the body forward
What does the ability to walk independently due to weakness depend on?
- which muscles are affected
- how weak are the affected muscles
- what’s the capacity of other muscles to compensate
What effects does paresis following CVA have on gait?
- There is a lack of phasic activation of the gastroc and tibialis anterior muscles
- There is also excessive hyperextension of the knee during stance and a lack of knee flexion during swing
Strength and gait velocity have a _____ relationship
non-linear
Describe the relationship between strength and gait velocity
There is a threshold in which strength must be at in order for walking to occur and there is also a ceiling at which an increase in strength does not influence gait speed
What are 4 compensatory strategies used to advance the swing leg due to decreased hip flexion?
- activation of abdominal muscle
- circumduction
- contralateral vault
- leaning the trunk laterally to opposite side
Abnormal velocity-dependent EMG recruitment during muscle lengthening is associated with what component?
Spastic
Define spasticity
abnormal velocity-dependent recruitment of muscle during lengthening
What are the 2 ways in which spasticity contributes to gait disorders?
- through inappropriate activation when muscle is lengthened during the gait cycle
- through alterations in mechanical properties of the muscle causing changes in intrinsic stiffness
Describe the knee angle in patients with spastic hemiparesis following initial contact
During initial contact the triceps surae musculature is stretched which results in early activation of the muscles. This results in shortening of the muscle before the body has passed ahead of the foot, pulling the lower leg backward and producing knee hyperextension
Describe normal modulation of the soleus stretch
In normal modulation there is a large-magnitude stretch response during stance phase, minimal response to stretch in the transition from stance to swing (60% of gait cycle), and 50% the activation level during swing compared to stance
Describe modulation of the soleus stretch in patients with MS
They show very little modulation of stretch reflex amplitude throughout the gait cycle
How do spastic plantarflexors affect gait?
They produce toe-drag which affects forward foot clearance during swing
What are 4 coordination problems that may lead to gait impairments?
- Abnormal synergies
- Inappropriate activation unrelated to a stretch
- Cocontraction of agonist and antagonist muscles
- Inadequate scaling of muscle activity
Loss of selectivity in motor output is associated with what component?
Cocontraction
Children with ______ tend to exhibit cocontraction of the quads and hamstrings during gait
spastic diplegia
Abnormal synergies results in what?
loss of fractionation movement
Loss of fractionation movement is associated with lesion to which tract?
corticospinal
Changes in mechanical properties of the muscle tendon systems is associated with what component?
nonneural
Non-neural impairments can also be referred to as what?
Musculoskeletal Impairments
What are 4 non-neural/musculoskeletal impairments that contribute to gait dysfunction?
- Decreased ROM
- Weakness
- Contractures
- Changes in alignment
How do changes in the passive properties of the musculoskeletal systems and limited ROM impair gait?
They impede the ability of muscles to generate power at different speeds
What are the 2 functions of sensory inputs during gait?
(1) a trigger for initiation of swing
(2) for adapting locomotion to changing environmental conditions
Abnormal mobility is associated with what 3 types of sensory deficits??
- Somatosensory deficits
- Visual deficits
- Vestibular deficits
What do somatosensory deficits result in?
gait ataxia
Gait ataxia becomes more affected without or with inaccurate _____ inputs
visual
Loss of ______ can cause reduced modulation of muscle activity throughout the gait cycle
proprioception
What is vision critical for during gait?
anticipatory control and obstacle avoidance
Loss of visual inputs affects what 2 things?
stability and adaptability
What does the functional consequence of vestibular deficits depend on? Explain…
the age at the time of loss of vestibular loss
- Infants: have near-normal posture and gait;
- Adults: experience gait ataxia and difficulty stabilizing the head in space
What are 3 disorders that tend to develop when there is impairment of the perceptual system?
- Body image/scheme disorder
- Spatial relation disorders
- Pain disorders
Body image/scheme deficits result in what 3 gait deviations?
- Decreased stability (ipsilateral trunk lean towards the stance leg)
- Inappropriate foot placement
- Difficulty controlling the center of mass relative to a changing base of support
What do spatial relation disorders impact?
The ability to navigate safely through the environment
Pain that causes antalgic gait is characterized by what 4 things?
- decreased velocity
- shortened stance
- stiffer limbs
- decreased forceful foot contact or push-off
What are 4 compensatory strategies used in the presence of pain?
- Reduced weight bearing on painful side
- Avoidance of impact loading
- Reduced joint excursion
- Decreased joint compressive forces
The last system that can cause abnormal mobility is the _____ system.
cognitive
What are 2 major risk factors associated with cognitive deficits for falls?
- dementia
- attentional demands
What 3 factors limit participation in the mobility domain?
- balance
- gait velocity
- strength in the hemiparetic limb
