Psychosocial Aspects of SCI and Locomotion after SCI Flashcards
What is a common musculoskeletal consideration in an older individual with a chronic SCI and the use of a wheelchair?
shoulder pain
Example of shoulder pain outcome measure for wheelchair users:
Wheelchair User’s Shoulder Pain Index (WUSPI)
- Self-report measure of shoulder pain experienced during functional activities, designed for individuals who use manual wheelchairs.
- Consists of 15 questions, each scored using the 10-point, ordinal visual
analog scale (VAS) with 0 indicating no pain and 10 indicating the worst
pain. - The maximum score is 150, with higher scores reflecting worse pain.
- If the patient does not perform an activity, there is the option to choose “not
performed.”
CATEGORIES:
-transfers
-self-care (ADLs)
-wheelchair mobility
-general activities
When we discuss a patient’s function, we identify them by their level that is/isn’t functionally innervated.
Select the correct response: is or isn’t
is
What ISNSCI levels have the best prediction for recovery of walking?
AIS C and D - 84% demonstrated recovery of walking
Walking recovery prediction LEMS < or equal to 20
limited ambulators, slow walking velocities, higher heart rates, higher energy expenditure
Walking recovery prediction LEMS > or equal to 30
community ambulators
How many ppl initially classified as AIS A convert to AIS B or AIS C?
10% convert to B
10% convert to C
80% remain complete
** when initial neuro exam is completed within first 72 hours post injury
AIS B and pin prick for walking recovery
pinprick preservation may demonstrate better walking recovery *sparing of motor tracts
AIS C percentage predicted to recover walking ability
75% expected to recover SOME walking function
-does not account for LE bracing and assistive devices
AIS D percentage predicted to recover some walking ability
100%
-with exam 72 hours post-injury
Why does time matter in regards to recovery of walking ability in those with SCI?
Reactive plasticity may be more sensitive in acute vs. chronic stages of recovery
-more potential for plastic changes to occur during acute SCI compared to chronic
-3 month delayed step training in rats → less effective than
initiated shortly after injury
- Acute SCI > Improvements in locomotor function, dec. tissue loss
caudal to lesion, inc. allodynia
-degree and mag of change is greatest closest to injury onset
CPR using S1 dermatome to predict independent walking following SCI
In the whole validation dataset, normal pinprick sensation bilaterally at S1 had a PPV of 86% (95% CI = 82–89%) for independent walking.
Any pinprick sensation unilaterally at S1 had a PPV of 76% (95% CI = 74–79%) for independent walking.
The absence of pinprick sensation unilaterally at S1 had a NPV of 83% (95% CI = 82–85%) for independent walking. (8 out of 10 will not endorse independent walking)
- can use our CPR to predict – within 31 days after SCI – who is likely to recover independent walking one year after traumatic SCI.
Extrinsic factors that impact recovery of walking
motor learning
motor relearning
electrical stimulation
pharmacology
Neural control of locomotion
1.) Sensory input to the spinal cord
2.) afferent input to supraspinal centers
<spinal>
3.) Efferent output to spinal centers
4.) Motor output to locomotor muscles
when there is injury to brain or SC--> strengthen what is preserved and what is remaining --> interneurons within SC can still help to relay information regarding locomotion
**supraspinal input is NOT required for walking function
</spinal>
Sensory afferents drive motor output
- Interneuronal spinal networks can be influenced by afferent input.
- With REPETITIVE presentation of
specific sensory information, the
spinal cord can integrate sensory
information and can adapt in a task
specific manner.
-Repetitive training can facilitate the functional re-integration of available supraspinal pathways
Foundational development of locomotor training
CAT STUDY
-training and task specificity matters
-cat did not have any supraspinal input from brain although the cat was able to increase motor skill acquisition of stepping and walking over time; increased coordination with stepping over time too
Relationship between stepping and automaticity of certain muscles
-when compared to knee extension and multi-joint movements, there was a much greater automatic turning on and off of muscles during stepping
** most EMG activity seen with stepping
Relationship between gait speed and EMG activity
-EMG amplitude increases and burst duration decreases with faster stepping speeds independent of supraspinal influence
-the SC interprets velocity-dependent afferent input during stepping
-stepping faster increases mm. activity and improves locomotor patterns
How load affects walking in those recovering from SCI
-SC interprets limb loading during stepping
-EMG amplitude increases with higher limb loading independent of supraspinal influence
-weight-bearing increases muscle activity and improves locomotor patterns
Guiding principles for locomotor training in individuals recovering from SCI
-maximize WB on the legs
-optimize sensory cues appropriate for motor task
-optimize kinematics for each motor task
-maximize recovery strategies, minimize compensatory strategies
Strategies to maximize weight bearing on legs
- Bear weight through legs during transfers
- Encourage to stand as often as possible at home
- Lower body weight support
Strategies to optimize sensory cues appropriate for motor task
- Step at pre-injury walking speeds
- Hip Extension and Weight shift
- Reciprocal arm swing
- Contralateral limb loading
Strategies to optimize kinematics for each motor task
- Generate sensory information essential for driving neural recovery
- Focus on upright posture of head, trunk, pelvis, and legs.
- Quality Practice, in addition to quantity
strategies to max recovery strategies and minimize compensatory strategies
-promote independence before providing assistance
-LRAD should be used when needed
Findings from CPG to improve locomotor function
POPULATION: improve walking function of patients with a history of stroke, motor incomplete SCI, or TBI > 6 months duration (+UMN signs) –> CHRONIC
FINDINGS: Task-specific walking training should be performed to improve walking speed and distance in those with acute-onset CNS injury
–> only at HIGH INTENSITY (85% HR max) or with augmented feedback (virtual reality).–> to improve walking speed and distance
WHY DID THEY COMBINE DIAGNOSES:
-all three had acute onset of damage to supraspinal or spinal pathways (UMN presentation)
- Relative consistent patterns of recovery: neuromuscular weakness and
discoordination, spasticity, hyperactive reflexes +, and classical neuromuscular
synergies.
Things clinicians may consider based on locomotor CPG
-strength training at >/= 1 rep max
-circuit training, cycling, or recumbent stepping (up to 85% HR max)
-balance training with VR
–> to improve walking speed and distance
Things clinicians SHOULD NOT consider based on locomotor CPG
-static or dynamic balance activities including pre-gait
-BWSTT
-robot assisted gait training
Limitations of CPG
-only RCT
-highly heterogenous patient populations
-most papers compare something to nothing
-usual care poorly defined
-only included patients that were already ambulatory and > 6 months post injury –> what if your patient can’t walk (yet)
Principles of experience-dependent neuroplasticity
-use it or lose it
-use it and improve it
-specificity
-repetition matters
-intensity matters
-time matters
-salience matters
-age matters
-transference
-interference
Active ingredients in neurologic PT
Specificity Matters → Nature of Practice [Work on walking to improve walking]
Intensity Matters → Workload of Practice [HR/BDNF Expression]
Repetition Matters→ Amount of Practice [Lasting neural changes]
Salience Matters→ Context of the Practice [Augmented Feedback/VR]
Is it better to start with errorless or error-based training in individuals who are working to recover walking function after SCI?
errorless to start–> then error-based–> then motor learning
-once they start to regain stance and swing phase in robot–> introduce more error based learning on treadmill
Benefits of augmented feedback for locomotor training
Increases rate of skill acquisition and promotes more efficient movements and encourages learning
Benefits of augmented feedback and rehab tech
o Inherent feedback mechanisms are often
impaired in patients
o Frequent feedback can enhance learning of
complex skills
o Feedback can improve movement
performance and decrease
compensatory movements
Intensity of training matters
-85% max HR training
-faster speed increases performance
-increases in gait speed, spatiotemporal and kinematic metrics
-mechanisms underlying locomotor changes are thought to include improvements in cardiovascular capacity and efficiency, increased neural drive, and the release of higher levels of neurotrophic factors that promote neuroplasticity
-practice needs to be DIFFICULT and EFFORTFUL to promote information processing
BDNF and relationship to neural plasticity
-voluntary and electrically stimulated motor activity increases BDNF
-mediates synaptic plasticity and promotes neuronal repair
-circulating BDNF increases after moderate and high intensity exercise –> if engaged in exercise before injury, this helps to prevent a decrease in BDNF levels after injury
**BDNF especially important in reorganization and regeneration of injured circuits
What is considered high-intensity exercise?
60-80% HRR or 70-85% HRmax
> 15/20 on Borg RPE scale (hard to very hard)
What factors do you need to consider when assessing an individual’s autonomic response to high-intensity exercise?
-objective response
-visual appraisal
-patient report
** very important when HR measures of exercise intensity are dampened due to meds like Beta Blockers or Autonomic Dysfunction in SCI
4 key biomechanical subcomponents of gait for improving locomotor deficits - from locomotor CPG
1.) Stance control
-look for the absence of a vertical limb or trunk collapse during stance
2.) limb advancement
-look for adequate foot clearance and a positive step length bilaterally
3.) propulsion
-Ability to move the center of mass in a specific direction during stance, separate from limb advancement
4.) postural stability
-look for maintenance of upright in sagittal and frontal planes, keeping the center of mass within the base of support
** GAIT TRAINING PERFORMED WHILE TARGETING 70-85% MAX HR OR 60-80% HR reserve
What is a great way to elevate heart rate into target zone during locomotor training?
challenging propulsion
-increased treadmill speed
-inclines
-banded posterior-directed resistance at pelvis
*NOTE: focusing on balance may decrease HR intensity, so the pt may benefit from alternating between propulsion demanding tasks and balance challenges within a session
Important components of task specificity and salience
-variability–> learning–> generalization
- retain fundamental motor task (interneurons)
-add challenge/specific contextual variations
-overlapping neuronal networks increases neural circuitry expansion
-must adapt to new environments/variable surfaces for community ambulation
Timeline of locomotor training after sci
1.) retrain the nervous system (prime the NS)
–activating and retraining the NM system via sensory input below the lesion
2.) overground training/skill acquisition
–focus on areas of greatest impairment
3.) community integration (HEP)
Recovery vs compensation
-not mutually exclusive!
-Target interventions that maximize the capacity of the nervous system and challenge the cardiovascular system
Recommendations for Orthotic Assessment and Decision Making and Prescription (ROADMAP)
-provides clinical algorithms for lower extremity orthoses decision-making
FACTORS TO CONSIDER:
-sufficient ROM
-physical AND cognitive ability and desire to meet ambulation goals
-adequate CV endurance and UE strength necessary for gait
KAFO considerations
-locked on default
-stance control is ankle-activated and acts like a pendulum
ROM necessary:
-0 deg ROM needed in locked position
-hip: 10 ext- 100 flex with extended knee
-knee: 0-60
-ankle: 0-10
STRENGTH necessary:
0/5 strength needed in locked except for knee extension
-hip flexion: 2+/5
-hip ext: >/= 3/5
-knee ext: <3+/5
-UE: ability to perform 50 continuous dips
AFO strength and ROM considerations
-strength recommendations vary based on type of AFO –> solid, hinged, ground reaction, anterior, posterior
STRENGTH:
-generally need <4/5 DF strength
-0/5 PF needed for solid ankle or ground reaction AFO
-usually need >/= 2/5 knee extension strength
-knee flexion strength must be greater than knee extension strength in ground reaction and anterior AFO or >/= 2/5 in soild ankle and hinged AFO
FES assisted orthoses
-PT in conjunction with using a properly fitted AFO appears to give same gait and balance benefits as training with FES assisted orthoses
-more compliance with FES compared to standard AFO
-less FOF with FES
-increased social confidence due to more normative appearance
Are exoskeletal robotic devices often covered by insurance?
no
FES parameters
AMPLITUDE: 1-140 mA
-primary determinant of strength of contraction
-want to achieve functional contraction while optimizing patient comfort
PULSE WIDTH/DURATION: 50-500 microseconds
-impacts which muscle fibers are recruited
-wider pulse widths activates more central pathways
FREQUENCY: number of pulses/unit of time
-controls type of contraction (twitch vs tetanic)
-impacts contraction rate/strength
-relationship to fatigue
FES cycling
Provides phase-dependent electrical stimulation to muscles of lower extremities and trunk.
-helps maintain muscle mass
-reduce muscle spasms
-improves local circulation
-maintains or increases ROM
-facilitate muscle re-education
Wide pulse width neuromuscular electrical stimulation
-allows for even greater recruitment of sensory and motor neurons due to increased pulse duration combined with increased pulse rate
WHY?
-activates central motor pathway and a large number of sensory neurons
-allows for more normalized recruitment:
slow–> fast twitch
-greater muscle torque and stronger contraction
-increased central state of excitability
-good when motor contraction is a challenge for the patient
—-> LMN issue
—-> Guillian Barre
What is neuromodulation?
-new research
-lowers the threshold of activity of nervous system, in order to depolarize and allow a person to experience contraction
Epidural stimulation - new SCI research
However, the brain cannot transmit signals to and from them because of the damage to the spinal cord. The implant device, through spinal cord stimulator surgery, helps to reactivate and use remaining intact neural networks within the spinal cord to direct the movements required to stand and take steps.
Epidural electrical stimulation involves the delivery of current to the dorsal aspect of the spinal cord through surgically implanted electrodes.
