Biofeedback

1 BIOFEEDBACK

(Occupational therapy for Physical Dysfunction. Catherine A. Trombly)

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Feed back is necessary for effective for motor learning.

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Motor performance is defined as the external consequence, of feedback of knowledge of results of a response is paired with internal kinesthetic cues associated with that responses.

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As a result person learns to discriminate specific kinesthetic stimuli linked to the more desired response, motor responses are learned if they are differentially reinforced through Neuro-physiological feed back system with out immediate & accurate feedback, skill cannot be developed easily & motivate to continue at the task will diminish.

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When trying to learn motor control in a limb that does not move predictably.

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Biofeedback coined term “Biological feedback” refers to the process of using instrumentation to feedback to the patient sensory information not usually in conscious awareness.

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By receiving & processing such information person can learn to control the monitored function because he known the effect of his efforts.

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Biofeedback is used to remediate motor impairments through occupation & is used as an enabling therapy at time when person is unable to engage in occupation

EMG BIOFEEDBACK: Surface EMG  Att. M  learn or relearn lost function. 

Each motor unit is composed of many motor fibres that depolarize more or less simultaneously when neuron belonging to that unit Activates them.

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When motor fiber depolarizes, small electric charge or voltage is generated.

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If many motor unit depolarize at same time, their signals are combined & the amplitude of the resultant signal increase as the no. of motor fibers depolarizing increases.

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When no contraction of extrafusal muscle is occurring when muscle is at rest, no signal is generated.

GOAL: EMG signals  Paretic M. Brain uses Proprioception input from joint & muscle as well as visual information to gain voluntary control over Paretic M.

2 1. Re-education of muscle contraction 2. Re-education of Spasticity 3. Recovery of Shoulder control Post stroke

4. Restoring Muscle Balance  S.A.  Lower Trapezius  Ext. Rotation TRAINING TO MODIFY MOVEMENT: 1. Baseline measurement of Patient Active (ROM) PROM are measured using a standard Goniometer & Recorded. 2. Dysfunctional joint or key joint if many are dysfunctional electrogoniometer.

3. Goal  Increase ROM 4. Facilitatory technique  useful to initiate motion 5. Improve speed & control of movement.

6. Session  10 – 15 mts. Tolerated, later increase duration frequency as tolerated. 7. Patient improves, feedback can be used in combination with therapeutic activities to maintain motivation. EFFECTIVENESS OF BIOFEEDBACK: 1. Control of the Autonomic system the concerned with control of movement. 2. Autonomic control have been found to benefit from relaxation training

3. Relaxation training + Biofeedback  effective 4. Biofeedback  encouraging + rewarding Relaxation 5. Biofeedback  universally successful, powerful panacea for all problem. ( Independent therapy) more beneficial as an integrated part of an appropriate treatment programme. 6. Teach patient control of their own body, be it movement control or autonomic , thus giving long term benefits in both Psychological & economic terms. 7. Recent careful meta analysis of 8 selected separate studies using EMG Biofeedback in the Rx of Hemiplegic Patient.

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BIOFEEDBACK ( 3RD Edit. Electrotherapy exp. Low and Reed, P.no. 157)

Def: Feedback is the coupling of the output of a process to the input.  Word has been defined as a method of controlling the system may be re inserting into it the result of its Past performance. This idea is involved in many physiological systems. MAJOR USES: 1. CONTROL OF MOTOR ACTIVITY & BODY MOVEMENT 2. Rx OF STRESS – RELATED CONDITION. NEGATIVE FEEDBACK: Deviation of the system in one direction leads to a correction of this deviation POSITIVE FEEDBACK: Occurs when the deviation leads to for their deviation in the same direction to the limits of the system. Biofeedback  refers to the application of –ve feedback to biological systems & specifying to the conscious control of some of those systems which are usually considered to be autonomically (Automatically) regulated. e.g: Temperature of the skin of the fingers is under sympathetic regulation which is largely dependent on the local &general environmental temperature. If a sensitive skin thermometer is applied to the skin of the finger most people are able to make a small alteration of the skin temp. at will. This may take a little time & some practice but can be done providing subject can see the thermometer reading & thus has immediate information of any change in skin temperature this is the feedback.

ALL HUMAN MOVEMENT IS CONTROLLED BY FEEDBACK INTRINSIC FEEDBACK  Information from Muscle spindle  Joint motion & postion sensors  Vestibular Apparatus  Skin sensors, visual cues EXTRINSIC FEEDBACK  PT, or Outside(environment) source

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EMG with surface electrodes to record  MUAP (Motor unit Action potentials)

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Suitable instrument are available to record

1. Body movement 2. Blood Pressure 3. Heart Rate (Electrocardiograph) 4. Electric Potentials developed in CNS [Electro-encephalograph] USES OF BIOFEEDBACK: 1. Neurology 2. Geriatrics 3. Orthopaedics, Sports Medicine •

For Condition in which control over some defective Motor action or movement is attempted.

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For Control of Stress Related Conditions  Some control over ANS is attempted; There is overlap between these purposes in that motor relaxation may be used for both.

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Chronic pain management: increasing self Awareness, Self esteem.

BIOFEEDBACK FOR THE CONTROL OF MOTOR ACTIVITY & MOVEMENT: ELECTOMYOGRAPHIC BIOFEEDBACK:

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Electrical signals generated when motor unit fibers  when one of these fibers, Muscle fibers it supplies all contract together causing Electrical disturbance called MUAP.

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When muscle contracts normally many 100 of these motor units fire asynchronously producing.

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Electrical Potentials which can be detected either by needle electrodes in the muscle tissue or Surface electrode.

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These signals can be displayed on an Oscilloscope screen or recorded on a strip of paper (Recorder)

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Fed to a loud speaker to generate a series of Audible clicks.

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Electromyographic display bears an approximate relationship to the magnitude of muscle contraction causing it.

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MUAP  will not all be equally detected & recorded.

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Biofeedback purposes, overall effect of stronger contraction leading to more & louder clicks, merging into a roar & a large display on the screen are adequate.

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Biofeedback usually provide both Audible, Visual Output, later moving meter needle rather than an oscilloscope trace. Smooth movement of the needle is Achieved by rectifying & Averaging motor unit electrical activity from the muscle, thus producing an output which varies smoothing with average muscle activity.

USES OF EMG BIOFEEDBACK FOR MOTOR CONTROL.

1. HP  Encourage Muscle action, Discourage Spasticity. 2. Spinal Cord Injury. Inhibition of Motor Activity during Passive static & Dynamic stretch of spastic muscle.

3. Control of Spasticity  HI (

), Multiple Sclerosis, Cerebral

Palsy.

4. Dystonic condition  (Spasmodic Torticollis) [Control of unwanted movement].

5. Recovering Peripheral Nerve injuries  Encourage Motor Activity. 6. Training specific motor activity – Strengthening. - Coordination of skilled movt. APPLICATION OF EMG BIOFEEDBACK: Practical Point: 1. To make good electrical contact the skin can be cleaned with an alcohol wipe [gentle rubbing with pumice is also recommended]. Saline gel smeared between electrodes, skin. 2. Taping the signal wires to the patient to reduce movement. Other forms of Biofeedback for control of activity: 1. Posture control. Psychoimmunology 2. Functional Breathing disorder 3. Control of Incontinence 4. Motor training control [motor re-education] 5. Weight bearing control 6. Joint angle control

6 7. Balance control 8. Movement practice: e.g. Biofeedback training was Rx of foot drop (CDF) 9. Recruitment of Q2 or relaxation of Hamstring Biofeedback for Rx of Stress related Conditions: 1. Essential Hypertension 2. Cardiac Arrhythmias 3. Raynaud’s Disease 4. Migraine 5. Epilepsy 6. Tension Headache 7. Sports medicine MECHANISM OF BIOFEEDBACK:

1. Biofeedback works by making patient aware of his or her own sensation when dysfunction occurs, spasticity. 2. Once learned, control can be maintained. 3. In many patients however control is gradually lost when the immediate feedback is stopped.

4. EMG biofeedback works by Operat (Behavioural) conditioning because it has been found that the motor response can be conditioned without awareness on the part of the patient.

5. In order to maintain control the feedback must be withdrawn from some of the trials so that patient gradually learns response with progressively fewer feedback reinforcements, this is called Generalisation Training. Feedback should be proportional to the Response, thus strong muscle contraction should produce a strong signal. Visual signal such as Digital meter are better than Auditory feedback because direct comparisons can be made from one trail to another. Direct sensory information from the muscle is needed for control & without it. It seems unlikely that significant therapeutic benefits can occurs. This conforms with the successful effects of motor practice & Artificial Stimulation.

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EFFECTIVENESS OF BIOFEEDBACK: Ask Evaluation of EMG Biofeedback for Motor control.

GENERAL PRINICIPLES: Improves motor performance by facilitating (motor learning) (Shumway-cook) Feedback  Intrinsic  Extrinsic  KP  KR PHYSIOLOGICAL PRINCIPLES:

(Source of Task) (end results)

8 Preplanning is called feed forward or Open loop control. Biofeedback techniques need thus require, atleast at first, that patient utilize closed loop control.

Therapist

Patient

Biofeedback instrumentation

BIOFEEDBACK (J.J. p.# 46)

Biofeedback is the process of furnishing the information of body function to get some voluntary control over it. Information of body functioning is informed to the patient via visual or auditory signals by a suitable device. (Sabesti et.al, Matchews 1980) e.g: Cardio: B.P  V. C  Relax Neuro: Tension  over it waves more higher. Types of Biofeedback:

1. Myoelectric Biofeedback or EMG biofeedback  function of Motor, motor problem.

2. Postural Biofeedback  e.g. Scoliosis. 3. Electro goniometric biofeedback  monitor patient. 4. Pressure & force Biofeedback  Display pressure, force  Rx HP  encourage more weight on Affected side.

5. Orofacial Biofeedback  Helps Rx of C.P, prevents drooling of saliva, helps in swallowing, sucking, closing of jaw.

6. Toilet Training Biofeedback  Rx for bed wetting.

9 7. Stress Biofeedback  Tension headache  so much stress. Mental stress  monitor waves. Relax waves comes down.

8. Cardiovascular biofeedback  Hypertension, cardiac arrhythmia  Reading display  B.P increase, stress control over.

9. EMG Biofeedback  used in Diagnosis purpose  C.P, Polio, Neuro. used in Treatment purpose  Abnormal finding. PARTS OF EMG: Using EMG Feedback for Neuromuscular Re-education 1. Ground electrode.

2. Surface electrode  Placed on skin.  Amplifier  Audiospeaker  Visual display screen THERAPEUTIC INTERVENTION IN EMG FEEDBACK:

1. Select the muscle  Monitor 2. Preparation of skin  for Ω (Resistance) 3. Preparation of electrode & apply them to skin 4. To determine min. / max. reading EMG 5. Manipulate, control of machine 6. Facilitate, re-educate Neuromuscular movements actively 7. Disconnected from machine. Principles of EMG Biofeedback Impulse from Muscle, skin (cleaned)  Surface electrodes [over muscle or muscle group(MUAP)]  wire Amplifier  Audio signal  wave displaced  Oscilloscope  Rest, Insertional activity, spontaneous activity. Increase Muscle activity  Specific sound. C.P  Bike sound Muscular Dystrophy  fibrillation, Interference pattern 2. Postural Biofeedback: modified orthotic device Rx Scoliosis. 3. Electrogoniometric Biofeedback: monitor angles of joint. 4. Limitation of Biofeedback:

1. Accurate

3 elements missing go for traditional B.F.B

10 2. Relevant

Verbal commands

3. Rapid or Speed To improve motor learning. USES: 1. Peripheral nerve injuries (PNI) 2. Hemiplegics 3. Rx of Spasticity 4. Muscle strengthening 5. Improve relaxation 6. SCI 7. Dystonic Condition 8. Functional Re-education 9. Cardiovascular condition Advantages of Biofeedback: 1. Clear information of about the Body function 2. It does not need sophisticated skill or understanding

3. It saves time of the Patient  sophisticated. Disadvantages: 1. Rx the symptoms, but not underlying cause.

2. Biofeedback Training  not commercial & not available in all places. 3. Patient not allow wire on their body.

4. C.P  M.R, Epilepsy Used carefully for reinforcement.

Response feedback: 

Direct result of Muscle contraction

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Feedback gives information about environment

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It gives us know of Performance & know of Results.

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It is derived from ext. sources  Ears, Eyes, Skin.

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Internal sources  Proprioceptors, Labyrinthines.

DEFINITION: Biofeedback is defined as technique of using equipment to reveal to human being some of their internal physiological events, inform auditory, visual signals itself, this technique insults person volition into gap of open feedback loop hence name artificial Biofeedback. 

Generation of information within brain without direct reference to the periphery.

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Monitoring of movement

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Comparison between intended motor output & appropriate motor programme.

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PT on the primary of tactile & proprioceptive inflow may be misplaced.

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Bizzi & Polit comment that proprioceptors have uncertain role in the execution of voluntary movts.

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Taub & Berman Proprioceptive feedback may accompany movement  this does not mean essential to that movement.

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Miles & Evarts  motor organization theories in attempt to organize data

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Anatomical finding regarding:  C.N.S – (Open loop) control.  P.N.S – Closed loop control.

Preprogrammed movt.

Reed: Afferent (sensory) Efferent (motor) CONCLUSION:

1. Biofeedback is logical adjust to therapy exercise because most exercise require contraction or relaxation of muscle. 2. Rehabilitation purpose general relaxation, joint angle biofeedback. 3. Biofeedback is used most commonly by person familiar with technology & importance of kinesiological data that are with fundamental element of biofeedback in therapeutic exercise.

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