Biofeedback (3)

Types of Biofeedback
EMG biofeedback in neurological conditions

1. BIOFEEDBACK 1

2. Contents Introduction Principle Biofeedback Equipment Feedback Loop Types of Biofeedback Electromyography Types of Electrodes Prerequisites Adjuncts 2

3. Indication & Contraindication Precautions Advantages & Disadvantages Application of EMG Biofeedback Evidence for EMG Biofeedback 3

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. 4

5. 3 professional biofeedback organizations, gave a definition for biofeedback in 2008  Association of Applied Psychophysiology & Biofeedback(AAPB)   Biofeedback Certification International Alliance (BCIA) The International Society for Neurofeedback and Research (ISNR), 5

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. 6

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 7

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.” 8

9. Four primary factors that influence motor learning are : Stage of learner Type of the task Feedback Practice 9

10. Feedback FEEDBACK Intrinsic Extrinsic 10

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 Knowledge of results Knowledge of performance 11

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. 12

13. Biofeedback Equipment 3 essential components Transducer/Detector Can be a pair of electrodes or pressure or temperature transducer. It detects minor physiological variable like blood flow, HR, electrical activity P roduces a corresponding signal which changes as the physiological variable changes. 13

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 14

15. Feedback Loop Subject Equipment Conscious Control Transducer (detector) Physiological Change Visual or Audible Perception Signal Processing Visible or Audible Display 15

16. Types of Biofeedback Electromyography Feedback thermometer Feedback goniometer Electrodermograph Electroencephalography Photoplethysmography Electrocardiogram Pneumography Capnometer Rheoencephalography Hemoencephalography 16

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 . 17

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  18

19. Electrodermograph/GSR M easures skin electrical activity directly (skin conductance and skin potential) and indirectly (skin resistance) using electrodes placed over the digits or hand and wrist . Treating anxiety disorders, hyperhidrosis and stress. Also used as an adjunct to psychotherapy to increase awareness of the emotions. 19

20. 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 . 20

21. Photoplethysmography M easures the relative blood flow through a digit T reating chronic pain, edema , essential hypertension, Raynaud’s disease, anxiety, and stress . 21

22. 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. 22

23. 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 23

24. 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. 24

25. 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 25

26. 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 Input Phase Processing Phase Output Phase 26

27. 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 27

28. Sound Offers audible feedback along with visual information C hange in sound such as the frequency & pitch of the ‘beeps’ increases with increased EMG activity. 28

29. 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”. 29

30. 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 30

31. 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. 31

32. Types of Electrodes It is a device that converts minute ionic potential into electric potentials. Types Stimulating Electrode Recording Electrode Active Electrode Reference Electrode Ground Electrode 32

33. Recording Electrode Surface Electrode Needle Electrode 33

34. 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. 34

35. 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 35

36. 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 36

37. 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 37

38. 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 38

39. Adjuncts PNF , ice , vibration , even electrical stimulation in con junction with biofeedback can enhance the patients motor performance. T herapist gives verbal reinforcement and manual assistance such as tapping, tendon pressure or putting the muscle on stretch, the patient attempts to perform that activity. 39

40. 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 INDICATIONS 40

41. Contraindications Unhealed tendon grafts, avulsed tendons Dermatological Conditions like eczema, dermatitis Unstable fractures & 3 rd degree tears of muscle fibre Allergy to electrode material or gel Patients with pacemakers Patients unable to follow and execute commands 41

42. Precautions Diminished skin sensations Epileptic patients: visual display might produce an adverse response 42

43. 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 43

44. Disadvantages Painful & expensive procedure Useful only with other clinical measures Not feasible in all kind of set ups Can cause infection (invasive procedure) 44

45. 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 45

46. General Training Principles Order of progression of treatment Goal selection Dual channel monitoring Supplemental techniques Weaning of biofeedback Targeted Muscle Training methods Motor Copy 46

47. Neuro Rehabilitation 3 types of biofeedback used EMG biofeedback Position biofeedback Force biofeedback 47

48. 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 48

49. 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 49

50. 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 50

51. For Muscle Recruitment Wrist & Finger Extensors 51 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

52. S pinal 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 52

53. Balance Training Posturography feedback is used Useful in treatment of Geriatric population P atients with balance impairments like Ataxia, Multiple Sclerosis Vestibular Rehab 53

54. 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. 54

55. 55

56. Evidence for EMG biofeedback 56

57. 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. 57

58. 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. 58

59. 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. 59

60. 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 60

61. References Biofeedback-principles & practice for clinicians.- Basmajian. Physical rehabilitation- Susan o sullivan 61