Biofeedback

What is Biofeedback?

• Technique allowing individual to determine activity levels of a physiological process

• With training → learn to manipulate/control the process

• Uses feedback from physiological activity to develop voluntary control.

EMG Biofeedback

• Uses electronic/electromechanical instruments to measure + process muscle activity

• Provides auditory + visual feedback

• Helps patient understand/control muscle activity

• Used e.g. during ambulation in brain injury, stroke + cerebral palsy

Noise

• Surface electrodes → record electrical activity from underlying tissue

• Electrode positioning important for accuracy

• Electrode movement → noise

  • Clean electrodes + secure electrode + lead to skin

• Light skin abrasion → ↑ contact + ↓ noise

• Place electrodes parallel to dominant muscle fibres

Sensitivity

• Gain = sensitivity

• Low gain → ↑ muscle activity needed for feedback

  • → maximal contraction in athletes

• High gain → ↓ muscle activity needed

  • → paralysed muscle/nerve damage

  • → relaxation + ↓ muscle activity (e.g. tension headaches)

Feedback Settings

• Sound or visual → choose based on patient

• Set threshold → no feedback below threshold

Peak Hold OFF

• Instantaneous feedback

• → useful for muscle twitch

Peak Hold ON

• Feedback based on previous 3 min

• → useful for max strength training

Evidence for biofeedback

• Works best integrated with exercise programmes

• Effective across a wide range of conditions

• Useful in physiotherapy rehab when used with exercise

• Aim: empower patient → perform effective exercises