Types of Biofeedback EMG biofeedback in neurological conditions

1. BIOFEEDBACK
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2. Contents
1. Introduction
2. Principle
3. Biofeedback Equipment
4. Feedback Loop
5. Types of Biofeedback
6. Electromyography
7. Types of Electrodes
8. Prerequisites
9. Adjuncts
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3. 10. Indication & Contraindication
11. Precautions
12. Advantages & Disadvantages
13. Application of EMG Biofeedback
14. Evidence for EMG Biofeedback
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4. Introduction
 Father of Biofeedback: John Basmajian
 Biofeedback is a technique which enables
the individual to readily determine the
activity levels of a particular physiological
process, and with appropriate training,
learn to manipulate the same process.
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5.  3 professional biofeedback organizations, gave
a definition for biofeedback in 2008
1. Association of Applied Psychophysiology &
Biofeedback(AAPB)
2. Biofeedback Certification International Alliance
(BCIA)
3. The International Society for Neurofeedback
and Research (ISNR),
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6.  “Biofeedback is a process that enables an
individual to learn how to change physiological
activity for the purposes of improving health and
performance.
 Precise instruments measure physiological
activity such as brainwaves, heart function,
breathing, muscle activity, and skin temperature.
 These instruments rapidly and accurately 'feed
back' information to the user.
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7.  The presentation of this information often in
conjunction with changes in thinking, emotions,
and behaviour supports desired physiological
changes.
 Over time, these changes can endure without
continued use of an instrument.”
Association for Applied Psychophysiology and Biofeedback. 2008-05-18
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8. Principle
 Biofeedback is based on the principle of
MOTOR LEARNING.
 Schimdt defined motor learning as “a set
processes associated with practice or
experience leading to relatively permanent
changes in capability for producing skilled
action.”
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9.  Four primary factors that influence
motor learning are :
1. Stage of learner
2. Type of the task
3. Feedback
4. Practice
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10. Feedback
FEEDBACK
Intrinsic Extrinsic
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11.  INTRINSIC
It is the body’s internal feedback
mechanism which uses visual, auditory,
vestibular, and proprioceptive mechanism.
 EXTRINSIC
It is derived from external source.eg
biofeedback signal, external
tapping,brushing.
Two types of extrinsic feedback
1. Knowledge of results
2. Knowledge of performance
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12.  Knowledge of results:- KR is feedback given
after performance of a task . Feedback given
about the outcome of the task is KR.
 Knowledge of performance:- KP is feedback
given during and after performance of a task and
is related to how the task was performed.
 Biofeedback given continuously during
performance of a task is knowledge of
performance feedback.
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13. Biofeedback Equipment
 3 essential components
1. Transducer/Detector
 Can be a pair of electrodes or pressure or
temperature transducer.
 It detects minor physiological variable like
blood flow, HR, electrical activity
 Produces a corresponding signal which
changes as the physiological variable
changes.
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14. 2] Signal Processor
May amplify, filter or average the signal and
convert it into useful form which can be displayed
and explained to the patient.
3] Display
Used to display processed signals.
Can be visual, audible or both
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15. Feedback Loop
Subject Equipment
Conscious
Control
Transducer
(detector)
Physiological
Change
Visual or Audible
Perception
Signal Processing
Visible or Audible Display
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16. Types of Biofeedback
 Electromyography
 Feedback thermometer
 Feedback goniometer
 Electrodermograph
 Electroencephalography
 Photoplethysmography
 Electrocardiogram
 Pneumography
 Capnometer
 Rheoencephalography
 Hemoencephalography
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17.  Feedback Thermometer
 Detects skin temperature with
a thermistor (a temperature-sensitive
resistor) usually attached to a finger or toe.
 Raynaud’s disease, chronic pain, oedema,
essential hypertension, anxiety and stress.
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18.  Feedback goniometer
 This is an elastic structure that gives a
feedback to the patient when the joint has
reached a predefined joint angle.
 Also monitoring joints that do not have a
stable rotation axis, such as the thoracic
scapula because, unlike other joint
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19.  Electroencephalography
 An electroencephalograph (EEG) measures
the electrical activation of the brain from
scalp sites located over the human cortex.
 Attention deficit hyperactivity disorder
(ADHD), learning disability, anxiety
disorders, depression, migraine, and
generalized seizures.
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20.  Photoplethysmography
 Measures the relative blood flow through a
digit
 Treating chronic pain, edema, essential
hypertension, Raynaud’s disease, anxiety,
and stress.
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21.  Electrocardiogram
 Activity of the heart and measures the inter
beat interval.
 Biofeedback therapists use heart rate
variability (HRV) biofeedback when treating
asthma, COPD, depression, fibromyalgia,
heart disease.
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22.  Pneumography
 Dysfunctional breathing patterns include
clavicular breathing, reverse breathing
behaviours which include apnoea, gasping,
sighing, and wheezing.
 Provide feedback about the relative
expansion/contraction of the chest and
abdomen, and can measure respiration rate
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23.  Capnometer
 A capnometer or capnograph uses an
infrared detector to measure end-tidal CO2
 Anxiety disorders, asthma, chronic
pulmonary obstructive disorder (COPD),
essential hypertension, panic attacks, and
stress.
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24. Electromyography(EMG)
 Electromyography (EMG) is the study of
muscle function through analysis of the
electrical signals emanated during muscle
contraction.
 Electromyogram records the motor unit
action potentials (MUAP’s) produced as a
result of recruitment of the motor units
following muscle contraction
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25.  The depolarisation produced at the motor
unit is manifested as motor unit action
potential (MUAP)
 This MUAP is recorded and displayed
graphically as EMG signal.
 3 Phase System
1. Input Phase
2. Processing Phase
3. Output Phase
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26. Features of EMG Device
 Gain Settings: Affects the basic sensitivity
of the machine
1. High gain setting:
 Highly sensitive
 Small flicker produces large response
 Used for paretic muscles& nerve injury
2. Low gain setting:
 Patient requires to make considerable effort
 Used in later stages of rehabilitation
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27.  Sound
 Offers audible feedback along with visual
information
 Change in sound such as the frequency &
pitch of the ‘beeps’ increases with
increased EMG activity.
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28.  Threshold
 Enables the patient to set targets.
 Buzzer is heard only when patient generates
specific level of muscle activity & threshold is
reached.
 Once patient exceeds this level, threshold is
increased & he is motivated for further recruitment
of muscle activity. This is called “shaping of
responses”.
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29.  Peak Hold Facility
 Enables the signal to be fed back on a
continuous basis (Peak Hold OFF) or by
providing the peak signal over a slower time
frame (Peak Hold ON e.g.3 seconds)
 Peak hold on is useful in later stage
recovery when sustained activity is more
important than instantaneous EMG spikes.
 Peak hold off used for patients who are
struggling to achieve significant EMG
activity
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30. Visual Feedback
 Lights (LEDs)
 Meter Deflection
 Video Monitors: Pattern generated is used
as a template for targeted activity.
 Oscilloscope:
 Generates raw EMG
 More useful for therapist to compare with
integrated EMG displayed on the monitor.
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31. Types of Electrodes
 It is a device that converts minute
ionic potential into electric potentials.
Types
Stimulating Electrode Recording Electrode
1. Active Electrode
2. Reference Electrode
3. Ground Electrode
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32. Recording Electrode
Surface Electrode Needle
Electrode
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33. Prerequisites
Essential factors to determine if patient is an
appropriate candidate for treatment :
 Potential for voluntary control must exist
before feedback training has begun.
 Patient motivation & cooperation are
essential.
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34.  Procedure
Select the muscles to be monitored.
Prepare the skin for the surface electrode
Apply the electrodes over the prepared skin
Determine the baseline readings of the muscle to be
stimulated
Set appropriate goal for the patient & help in
understanding of the task
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35. Set audio & visual thresholds which have to be reached
during the session
Progress if two out of three trials are successful & goal is
attained
Patient learns to manipulate the controls and elicit
maximum response
Use other neuromuscular re education techniques
Remove & clean the device and patients skin
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36. Therapeutic Intervention
 EMG biofeedback can be used only to help
the patient increase or decrease muscle
activity
 Up Train
 To increase the recruitment of weak
muscles
 Patient is asked to increase the output
(frequency and amplitude) of EMG signal
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37.  Down Train
 Aim is to decrease the activity of overactive
or spastic muscle
 Patient is asked to focus on relaxing the
muscle to reduce the EMG output
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38. Adjuncts
 PNF, ice , vibration , even electrical
stimulation in con junction with biofeedback
can enhance the patients motor
performance.
 Therapist gives verbal reinforcement and
manual assistance such as tapping, tendon
pressure or putting the muscle on stretch,
the patient attempts to perform that activity.
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39. Stroke
rehabilitation
Muscle re
education
SCI
Control Spasticity
Balance Training
Neurological Musculoskeletal
Chronic back pain
Post muscle
transfers
Relaxation post
strain
Muscle
strengthening
Cardiovascular Miscellaneous
Raynauds
Disease
Urinary
Incontinence
Fecal
Incontinence
Headache
Stress disorders
Control Heart rate
Supraventricular
arrhythmias
Ventricular ectopic
beats
Behavior Analysis
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40. Contraindications
 Unhealed tendon grafts, avulsed tendons
 Dermatological Conditions like eczema,
dermatitis
 Unstable fractures & 3rd degree tears of
muscle fibre
 Allergy to electrode material or gel
 Patients with pacemakers
 Patients unable to follow and execute
commands
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41. Precautions
 Diminished skin sensations
 Epileptic patients: visual display might
produce an adverse response
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42. Advantages
 Allows small changes in correct direction &
gradually build up into larger changes
 Useful when patient has wrong perception
of what they are doing which can be
rectified
 Encourages & motivate the patient
 Reduces sense of helplessness
 Serves as coping response to reduce
symptoms of stress
 Increases self efficacy by increasing
confidence
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43. Disadvantages
 Painful & expensive procedure
 Useful only with other clinical measures
 Not feasible in all kind of set ups
 Can cause infection (invasive procedure)
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44. Advantages over other
feedback
 Specificity, objectivity, accuracy and
quantitative nature of feedback
 Gives real time information
 Both therapist and patient can use the
information
 Can be recorded for comparison or
calculate improvement
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45.  General Training Principles
 Order of progression of treatment
 Goal selection
 Dual channel monitoring
 Supplemental techniques
 Weaning of biofeedback
Targeted Muscle
 Training methods
Motor Copy
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46.  Neuro Rehabilitation
3 types of biofeedback used
1. EMG biofeedback
2. Position biofeedback
3. Force biofeedback
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47.  EMG Biofeedback
 Weak & poorly controlled muscles
 Training relaxation of overactive muscles
 Determine patients potential
 Position Biofeedback
 Train regulation of movement
 Force Feedback
 Gives information regarding force being
transmitted through specific body segments
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48.  Spasticity Control
3 stages for training :
Stage 1 Stage 2 Stage 3
Spastic muscle at
rest
Reduce the
stretch stimuli
Maintain
relaxation inspite
of overflow
Train to inhibit
spasticity
produced by
dynamic
stretching
Training of active
use of spastic
limb
Activate the
antagonist &
inhibit co
contraction of
spastic target
muscle
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49.  Recovery & timing of Feedback
 As per Brunnstorm staging, “works with”
synergy to improve muscle activity of
paralysed muscle.
 For spasticity, training starts distally as
spasticity develops early in hand and wrist
rather than elbow & shoulder i.e goes
against the spatial rule
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50.  For Muscle Recruitment
Wrist & Finger Extensors
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Start with training by placing the wrist extensors in a stretched position
Place the electrodes over the wrist extensor group of muscles
Ask the patient to initially focus on isometric contraction of wrist
extensors
Use facilitation techniques
Later progress by placing the wrist in a shortened position and focus
on active extension

51.  Spinal Cord Injury
 Application is very limited in cases of spinal
cord injury
 Biofeedback is of no use in cases with
established complete cord injuries
 However it can be used in incomplete cord
injuries where some voluntary movement is
present and the muscles are innervated by
motor neurons below the level of lesion
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52.  Balance Training
 Posturography feedback is used
 Useful in treatment of
1. Geriatric population
2. Patients with balance impairments like
Ataxia, Multiple Sclerosis
3. Vestibular Rehab
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53.  Facial Hemiparesis
 Biofeedback can be used effectively in Bells
Palsy to improve muscle recruitment
 Mirror therapy is also proved to be very
effective in facial paresis provided some
voluntary movement is present.
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54. 55

55. Evidence for EMG
biofeedback
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56. Title,Year Conclusion
Effect of a Portable EMG-based
Combined Biofeedback Device
(PECBD) for the Rectus Femoris,
Biceps Femoris, and Tibialis
Anterior Muscles on Stroke Gait.
2012
Significant improvement seen in
step length, less-affected step
length, affected stride length, and
less-affected stride length in
stroke patients. The training
enabled the patients to dorsiflex
the ankle, attain heel strike at
ground contact, and increase in
hip and knee flexion during swing.
Effectiveness of EMG
Biofeedback on Improving hand
function in hemiplegic stroke
patients.
2012
The results of this study
concluded that EMG Biofeedback
along with conventional
physiotherapy is effective on
improving hand voluntary control
and hand function in subacute
stage stroke participants over the
period of four weeks.
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57. Title,Year Conclusion
A biofeedback cycling training to
improve locomotion: a case series
study based on gait pattern
classification of 153 chronic stroke
patients.2011
Study suggests that the treatment
can be beneficial for patients
having a very asymmetrical and
inefficient gait and for those that
overuse the healthy leg. The
results demonstrated that the
treatment is feasible and it might
be effective in translating
progresses from pedalling to
locomotion.
Task-oriented biofeedback to
improve gait in individuals with
chronic stroke: motor learning
approach.2010
A task-oriented BFB treatment
was effective in increasing peak
ankle power, gait velocity, and
stride length in a population with
hemiparesis.
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58. Title,Year Conclusion
Effect of EMG biofeedback training
of gluteus maximus muscle on gait
parameters in incomplete spinal
cord injury. 2013
The study concluded that EMG BF
when given specifically over
gluteus maximus resulted in
improvement of EMG amplitude
and various gait parameters
(walking velocity, cadence).
EMG Biofeedback and Exercise for
Treatment of Cervical and
Shoulder
Pain in Individuals with a Spinal
Cord Injury.2013
This study provides preliminary
evidence that EMG biofeedback
has value when added to an
exercise intervention
to reduce shoulder pain in manual
wheelchair users with SCI.
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59. Summary
 Definition as per AAPB
 Motor learning & feedback
 Types of Biofeedback
 EMG & device settings
 Prerequisites & Procedure
 Advantages & Disadvantages
 Application of Biofeedback
 EMG biofeedback in Neuro Rehab
 Recent studies on Biofeedback
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60. References
 Biofeedback-principles & practice for
clinicians.-Basmajian.
 Physical rehabilitation- Susan o
sullivan
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61. Thank You
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