Emg biofeedback


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for physiotherapy under graduate students

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  • Emg biofeedback

    1. 1. EMG-bio feed back
    2. 2.  An electromyography – is a clinical technique that involves recording of the electrical activity generated in a muscle (muscle AP) for diagnostic purposes An electromyogram - is a graphic representation of those electrical currents associated with muscle action
    3. 3.  It is a method of controlling a system by reinserting into it the results of its past performance. -wiener1948‘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 by an internalized mechanism.’
    4. 4. “Operant conditioning learning”
    5. 5.  Positive feed back Negative feed back
    6. 6.  Electromyographic  Photophlethysmography  Measures electrical activity in  Measures the amount of light skeletal muscle reflected by subcutaneous tissue Peripheral Temperature based on the amount of blood  Measures temperature flow changes in distal extremities  Galvanic skin response  Increased temperature  Measures electrical resistance in indicates a relaxed state the skin  Decreased temperature  Moist skin conducts a current indicates stress, fear, or better than dry skin anxiety© 2004
    7. 7. ADVANTAGES Chance to make appropriate small changes in performance Eventually larger changes or improvements in performance can be accomplished The goal is to train the patient to perceive these changes without the use of the measuring instrument so that he or she can practice independently
    8. 8. Biofeedback instruments may use the following signals/devices/sourcesEg: Temperature- thermometer-skin
    9. 9. Type Whats Measured Basic method Used ForBrain waveEEG Electrical activity in the Sensors placed on Alcohol and drug brain scalp addition, brain damage, epilepsy, hyperactivity, insomniaBreathing Breath rate, rhythm, Sensors around chest Anxiety, asthma, volume, and location and abdomen or hyperventilation around mouth and noseElectro dermal Sweat gland activity Sensors placed on the Anxiety, overactiveresponse muscle group in sweat glands questionElectro-myography May help treat Incontinence, muscle Muscle spasms and rheumatoid arthritis, pain, physical tension premenstrual rehabilitation, stress, syndrome, menstrual teeth grinding (TMJ), cramps, and tension headaches, menopausal symptoms torticollis ("wry neck")
    10. 10. 1.Providing feed back Appropriate Proportional Sensitivity and specificity of equipment Appropriate method Time/scheduled feed back
    11. 11. 2.User control Over the method3.Proper starting position4.Shaping behaviorAvoid fatigue Initial success Set upper and lower threshold Change goals
    12. 12.  It is a therapeutic procedure that uses electronic or electromechanical instruments to accurately measure, process, and feed back reinforcing information via auditory or visual signals. In clinical practice, it is used to help the patient develop greater voluntary control in terms of either neuromuscular relaxation or muscle reeducation following injury.
    13. 13. Identify Signal Get the eletromyographic signal from the body Amplify Signal Filter out background noise Similar to a volume control on a radio, enhance the strength of the signal to meaningful levels Rectify Signal Make all values “positive” Integrate Signal Group the data into meaningful clusters© 2004
    14. 14.  Muscle reeducation Regaining neuromuscular control Increasing isometric and isotonic strength of a muscle Relaxation of muscle spasm Decreasing muscle guarding Pain reduction Psychologic relaxation
    15. 15.  Measuring muscle activity Separation / filteration Electrodes Displaying the feedback
    16. 16.  Biofeedback Measures electrical activity of muscle, not muscle contraction. Gives information about the quality of a muscle contraction Does not measure the strength of that muscle contraction specifically.
    17. 17. “Active” Electrodes Detect electrical signal “Reference” Electrode Filters nonmeaningful information  Basic units have one channel composed of three surface electrodes on a self-adhesive electrode© 2004
    18. 18. electrical energy received through an electrode separated or filtered from other extraneous electrical activity on the skin amplifies the electrical energythen converted to information that has meaning to the user
    19. 19. • Noise must be eliminated• Noise – by power lines , motor , lights , appliances.• Accomplished by using 2 active electrodes and a single ground/reference electrode  differential amplifier  CMRR-common mode rejection ratio• Filters are also used• Use :  Mask true electrical activity  Decrease the reliability of the information being generated
    20. 20.  After filtering, signal indicates true muscle activity – “raw” activity Raw activity – alternating voltage Biofeedback measures the overall increase and decrease in electrical activity To obtain this rectification is done Rectified signal can smoothed and integrated
    21. 21.  Skin preparation Application of electrodes Selection of output modes Selection of sensitivity settings Comfortable positioning of the patient Begin with easy task Teach the patient how to use the unit Brief explanation Demonstration
    22. 22.  Skin preparation  Reduce skin impedance Positioning of electrodes  Placed as near to the muscle being monitored to minimize noise  Parallel to the muscle fibers Spacing between electrodes  More the distance between the electrodes – will include signal from nearby muscles Types  Surface electrodes  Needle electrodes
    23. 23.  Made of stainless steel or nickel plated brass kept in a plastic holder Size : 4mm in diameter – small muscle activity 12.5mm –for large muscle groups Increase in size will not increase the amplitude of the signal Conducting gel/paste/cream with high salt content is used Can be disposable and non-disposable
    27. 27.  Visual feedback Audio feedback
    28. 28. ▪ Line travelling across a monitor▪ Light/series of light that goes on and off▪ Bar graph▪ Incorporated video games
    29. 29. ▪ Tone▪ Buzzing▪ Beeping▪ Clicking
    30. 30.  An Increase  increased electrical activity  used to strengthen muscle contractions Decrease  decreased electrical activity  used for relaxation
    31. 31.  Goal is to reestablish neuromuscular control Used to regain normal agonist/antagonist muscle action For postural control retraining Useful in patients who perform poorly on manual muscle tests Balance/mobility
    32. 32.  Muscle guarding Muscle guarding different from muscle spasticity Goal : to induce relaxation or to modulate pain by reducing electrical activity Patient attempts to reduce visual/auditory feedback to zero Positioning is important Verbal cues should be given to enhance relaxation
    33. 33.  Purpose : reduce/modulate pain Breaking “pain-guarding-pain” cycle Reduces pain in headaches and low back pain Techniques of imagery and progressive relaxation is used
    34. 34.  Hemiplegia Stroke Spinal cord injury Spasticity Cerebral palsy Facial paralysis Urinary and fecal incontinence
    35. 35.  HTN Stress Reynauds disease Respiratory control
    36. 36.  severe psychosis depression psychopathic personalities diabetics and others with endocrine disorders Any musculoskeletal condition in which a muscular contraction might exaggerate that condition