Biofeedback in physiotherapy practice

Biofeedback machines commonly used in the physiotherapy practice are described along with available evidences for clinical use.
Most of the feedback modalities are described along with its use and the mechanism behind it.
22- Force platform- is the device used to measure the ground reaction forces in steady and/or in moving phase. Sensors in the force platform give visual feedback on the screen attached to therapist as well as patient about the weight distribution and other parameters of gait can also be measured.
33- Mirror -used as visual feedback to treat the pain as well as disability in different conditions. It healps to activate the mirror neuron in the brain. Mirrior therapy proposed by Ramchandran et al has been found most beneficial treatment in the phantom limb pain treatment

1. Biofeedback in physiotherapy practice Manasi Kulkarni Mpt - Neurophysiotherapy Guide: Dr. Suvarna ganvir D.V.V.P.F’s College of Physiotherapy, Ahmednagar

2. Content Biofeedback- introduction Types- 1) Physiological 2) Mechanical EMG RTUS HRV Respiratory feedback Force plat form Limb load monitor Inertial sensors Electro-goniometry TDU Pressure biofeedback

3. Introduction Feedback includes all the sensory information that is available as the result of a movement that a person has produced. This is typically called response- produced feedback. This feedback is usually further divided into two subclasses, that of intrinsic feedback and extrinsic feedback. Biofeedback is the technique of making unconscious or involuntary body processes perceptible to the senses to manipulate them by conscious mental control.

4. Relating to movement pattern used to achieve goal Outcome of the movement in terms of movement’s goal

5. Augmented feedback 1 Concurrent feedback Feedback presented during the movement 2 Terminal feedback Feedback is given after the movement 3 Immediate Feedback Feedback presented immediately after movement 4 Delayed feedback Feedback given after a brief time delay which allows time for introspection 5 Faded Feedback Feedback given first after every trial 6 Bandwidth-KR feedback Feedback given only when performance deivates from correct boundaries 7 Blocked Feedback One source of feedback is provided 8 Variable(random) Feedback Multiple source of feedback are provided

6. Advantages Patient makes changes in performance that are noted and rewarded Teaches patient to not rely on the trainer. Increases confidence Improves patient’s perception of what he/she is doing Can be used to detect the errors. Specificity, objectivity, accuracy and quantitative nature of feedback Can be recorded for comparison or to calculate improvement

7. Types Type Principle Electromyographic (EMG) Measures the electrical activity in skeletal muscles 2. Mechano-myographic Measures the transverse displacement of the skin over the target muscle based on the sound produced and /or skin tension. Quantifies oscillations in the skin caused by changes in muscle fiber. 3. Peripheral temperature Measures temperature in distal extremities( ex. Fingers) Increased temperature indicates relaxed state and decreased temperature indicate stress, fear or anxiety.

8. 4. Photoplethysmography Measures the amount of light reflected by subcutaneous tissues based on the amount of blood flow. 5. Galvanic skin response Measures the amount of perspiration on the skin by passing a small current through the fingers and/or palm. Sweaty skin contains salt and is a better conductor than dry skin.

9. Neuromuscular Feedback Cardiovascular Feedback Respiratory Feedback EMG RTUS HR HRV Measuring breathing

10. EMG EMG biofeedback is a method of retraining muscle by creating new feedback systems as a result of the conversion of myoelectrical signals in the muscle into visual and auditory signals.

11. Bradley et al conducted a study to examine the effects of electromyographic (EMG) biofeedback training on the recovery of gait in the acute phase post stroke Sample size -21 stroke patients Outcome measures- Physical examination (MAS, 10 mt walk test, sensation and proprioception), Psychological (MSQ, IQ) Conclusion: this study used EMG biofeedback as an adjunct to physiotherapy and represented relevant clinical practice, the results provide little evidence to support the clinical significance of using EMG biofeedback to improve gait after stroke .

12. EMG biofeedback can be used to either increase activity in weak or paretic muscle or it can be used to facilitate a reduction in tone is a spastic one. Draper and Ballard suggested that EMG biofeedback is more effective in facilitating the recovery of quadriceps femoris muscle peak torque than electrical stimulation treatment in participants post ACL reconstruction. NG and colleagues found that EMG biofeedback was an effective adjunct to therapeutic exercise for patients with patellofemoral pain syndrome. Armagan and colleagues demonstrated the potential benefits of EMG biofeedback in conjunction with exercise in maximizing hand function in hemiplegic patients.

13. RTUS RTUS send short pulses of ultrasound into the body and using reflections received from tissue interfaces, images of internal structures are produced thus RTUS is capable of giving immediate real-time visual feedback of muscle activity by allowing the user to directly see the muscle changing shape/length on a display.

14. RTUS has also been successfully used to provide visual feedback of pelvic floor muscle activation. Dietz et al. showed that 32 of 56 women learned correct activation of their pelvic floor muscles with less than 5 minutes of RTUS biofeedback training.

15. Heart rate monitor HR can be measured using a heart rate monitor or an electrocardiogram to deliver feedback to patients. HR biofeedback is a therapeutic approach which allows patients to control their HR by means of direct representation of the numerical value of HR on a wearable device such as a watch or a handheld display

16. Houser MM et el conducted a pilot study Purpose:  Use of HRMs for biofeedback during guided mindfulness, diaphragmatic breathing, and progressive muscle relaxation techniques could facilitate anxiety reduction as compared to these techniques alone. Sample size-53 patients. Intervention- 20 min session for both groups for 4 weeks Results: HRM group had significantly greater improvement in state anxiety. So It may be a useful clinical intervention for anxiety and can be easily incorporated by both behaviorists and non-behaviorist primary care clinicians into individual or group biofeedback treatment for patients with anxiety

17. Another study was conducted by Hallman on the stress management in patients with chronic neck pain.

18. Respiratory Biofeedback Respiratory biofeedback is delivered by measuring breathing using electrodes or sensors attached to the abdomen and by converting breathing to auditory and visual signals for the user. Teaching diaphragmatic breathing in patients with respiratory disease is the most common means of providing respiratory biofeedback

19. Kapitza et al. compared the effect of breathing exercises guided by placebo respiratory biofeedback to real respiratory biofeedback in a group of participants with chronic LBP. The intervention group received ordinary, synchronized feedback of their own breathing excursions, whereas the control group received no feedback, but a constant proxy signal corresponding to a breathing rate of approximately eight breaths per minute. While higher reductions in pain levels were noted at rest and during activity in the treatment group there was no significant differences between the groups at follow up

20. Force platform

21. Nicholas DS. Conducted s study in Stroke patients Measures : steadiness, symmetry , dynamic stability training Results : These systems are designed to provide visual or auditory biofeedback to patients regarding the locus of their center of force (COF) or center of pressure (COP), as well as training protocols to enhance stance symmetry, steadiness, and dynamic stability. Mechanism : platform system provides a COF measure or a COP measure is dependent on the strain-gauge setup within the force plates. Center of force is calculated only from the vertical forces projecting on the force plates. Center of pressure is calculated from both the vertical forces and the horizontal forces projecting on the force plates, thus accounting for horizontal shear.

22. Limb load monitor Incorporates a strain gauge attached to the sole or heel of the shoe. When a force or pressure is applied, the strain gauge is deformed and an auditory signal provides feedback to the wearer. As pressure increases, the signal becomes louder or more rapid. provides information about the amount of weight-bearing on a limb.

23. A study was done by Isacov et al. to see effect of weight bearing on the affected limb. Procedure – pre caliberation procedure was done , then pts asked to wt bear till the sound was heard . Device used- smart step Results- device proved to be reliable in improving body wt loading during gait rehabilitation

24. Inertial sensors Inertial sensing uses accelerometers and gyroscopes to estimate three-dimensional (3-D) kinematic information of a body segment, such as orientation, velocity and gravitational force.

25. Davis and colleagues used gyroscopic measurements to provide biofeedback and found significant changes in trunk angular displacement in both young and older participants during a number of balance tasks compared to control treatment. Verhoeff et al. also examined the effects of a gyroscopic biofeedback system on trunk sway during dual tasking (performing a cognitive and a motor task) while walking.

26. Electro-goniometry It is an electro-goniometer to identify the position of the limb segments to regulate the movement, or train timing and coordination for a movement. It gives a feedback to the patient when the joint has reached a predefined joint angle

27. Tongue display unit Study conducted by Vuillerme et al Sample size : 12 Clinical Use : Enhancing/preserving/ restoring balance Results: Centre of foot pressure (CoP) displacements were recorded using a force platform. Results showed reduced CoP displacements in the biofeedback relative to the no-biofeedback condition. Mechanism: its dense mechanoreceptive innervations and large somatosensory cortical representation, the tongue can convey higher-resolution information than the skin can

28. Pressure biofeedback A pressure biofeedback unit (PBU) is a tool developed to aid the retraining of muscle activity and can provide useful visual biofeedback during treatment.

29. Subjects :18 healthy subjects Procedure : subjects performed hip abduction with lumbar stabilization . Pressure biofeedback was used for lumbar stabilization . EMG activity was recorded from muscles . Results : hip abduction with lumbar stabilization is useful in excluding substitution by quadratus lumborum

30. Mirror

31. Summary Type of biofeedback Use 1. EMG activation of specific muscle, relaxation, pain reduction, Muscle reeducation, treating bladder dysfunction. 2. RTUS activation of muscle, reeducating muscle 3.HRV Relaxation, control manic attacks 4. Respiratory feedback Relaxation 5. Force platform Measure cop 6. Limb load monitor Weight bearing 7.

32. References Shumway-cook A., Woollacot M. Motor control theory and practical application. Starkey C. Therapeutic modalities. Stanton, R., Ada, L., Dean, C. M., & Preston, E. (2017). Biofeedback improves performance in lower limb activities more than usual therapy in people following stroke: a systematic review. Journal of Physiotherapy, 63(1), 11–16. Vuillerme , N., Pinsault , N., Chenu , O., Fleury, A., Payan , Y., & Demongeot , J. (2009).  A wireless embedded tongue tactile biofeedback system for balance control. Pervasive and Mobile Computing, 5(3), 268–275.   Draper V, Ballard L: Electrical stimulation versus electromyographic biofeedback in the recovery of quadriceps femoris muscle function following anterior cruciate ligament surgery. Phys Ther 1991, 71(6):455–461.

33. Ng GY, Zhang AQ, Li CK: Biofeedback exercise improved the EMG activity ratio of the medial and lateral vasti muscles in subjects with patellofemoral pain syndrome. J Electromyogr Kinesiol 2008, 18(1):128–33. Armagan O, Tascioglu F, Oner C: Electromyographic biofeedback in the treatment of the hemiplegic hand: a placebo-controlled study. Am J Phys Med Rehabil 2003, 82(11):856. Dietz H, Wilson P, Clarke B: The use of perineal ultrasound to quantify levator activity and teach pelvic floor muscle exercises. Int Urogynecol J 2001, 12(3):166–169. Kapitza KP, et al: First non-contingent respiratory biofeedback placebo versus contingent biofeedback in patients with chronic low back pain: a randomized, controlled, double-blind trial. Appl Psychophysiol Biofeedback 2010, 35(3):207–17. Isakov E. Gait rehabilitation: a new biofeedback device for monitoring and enhancing weight-bearing over the affected lower limb. Europa medicophysica . 2007 Mar;43(1):21 Cynn HS, Oh JS, Kwon OY, Yi CH. Effects of lumbar stabilization using a pressure biofeedback unit on muscle activity and lateral pelvic tilt during hip abduction in sidelying . Archives of physical medicine and rehabilitation. 2006 Nov 1;87(11):1454-8.