10 Biofeedback

what is biofeedback?

provides information about ourselves typically through the use of external instruments, can be thought of both as treatment and training

how is biofeedback used in a clinical setting?

used to monitor muscle activity by looking at the electrical signal produced during a voluntary contraction

how is integrated signals from EMG used for biofeedback?

used to drive visual or audible feedback, e.g. larger the signal the more lights/sound provided to the subject

what are the 3 things we are concerned about with biofeedback?

1. carry over - if things learned from biofeedback can be translated into real-world things

2. training dose - how much dose is needed to get a meaningful response

3. sensory substitution - are we strengthening the sensory path we want or getting info from a different mechanism

what is an EMG signal?

the total signal detected at the recording site

what are the 2 basic EMG biofeedback systems available?

stationary

portable

what is a stationary biofeedback system?

computer-based with subject tethered

what is a portable EMG biofeedback system?

self contained, can be telemeterized, data logger, or just feedback

how can muscle control via EMG be used?

selective training of VM/VL - contract independently of each other

incontinence/dysfunctional voiding problems

asthma treatment - decreased pulmonary impedance via increased relaxation of trapezius

trapezius muscle relaxation resulted in the redistribution of ____ in the shoulder.

how is this an example of inverse biofeedback mech?

muscle forces, increased EMG activity in rhomboid major and minor as traps relax

how has EMG biofeedback been used for cervical traction relief?

higher EMG in neck pain pts vs no neck pain, EMG decreases with traction

neck pain patients who had biofeedback during cervical traction took less time to get from start of traction force to optimum compared to conventional traction

what is functional sensory substitution?

biofeedback related to conditions where sensory loss has occurred, e.g. peripheral neuropathy, LE/UE prosthetic

what are problems with biofeedback?

noise - unwanted signal contaminating the EMG

electrode placement

where can noise come from in EMG?

narrow-band noise - AC lines/60 Hz

biological noise - EKG, respiration, movement, etc

cross-talk - signal from adjacent muscles or between instrumentation channels

artifacts - from electrodes or muscle length changes

EMG signals from a residual imb can be used to control ______.

electric prostheses

what does spectral analysis show?

changes in EMG that relate to muscle fatigue

may soon be available in a feedback format, can be used in sports med, ergonomics, research

neuroprosthesis uses inputs from ___ to assist patient or move robotic device

EMG