FROM MY PT SCHOOL NOTES · MODALITIES · UNIT 2 · CHAPTER 09
What Can Surface EMG Biofeedback Tell You?
Electrical activity at an electrode is a learning signal—not a direct measurement of muscle force.
At a glance
SIGNAL
Surface electrical activity
DISPLAY
Visual/auditory cue
TRANSFER
Task without the cue
What matters most
- Surface EMG converts local muscle electrical activity into visual or auditory information used for awareness, activation or relaxation.
- Skin preparation, electrode positioning, cross-talk, cable movement and noise influence amplitude and interpretation.
- External feedback can support practice, but a skill should also be tested without the display to assess transfer.
Safety and evidence limits
Do not compare EMG numbers across people or sessions as if electrode conditions are automatically identical. Avoid treating the waveform as a strength score.
Try a clinical decision
Scenario: A person can raise the EMG bar during practice but cannot reliably perform the target movement without the screen. What is missing?
Reveal the reasoning
Test retention and task carryover without the cue, then adapt practice and feedback frequency to support independent performance.
My original class sources: 15 Biofeedback.pdf. Supplementary context is not part of the original lecture packet. Educational summary, not a clinical protocol or device-setting guide.
