ELECTROMYOGRAPHIC (EMG) BIOFEEDBACK

ELECTROMYOGRAPHIC (EMG) BIOFEEDBACK

is a tool that helps patients learn how to better control their muscle activity. It does not treat the body with energy like heat or electricity—instead, it shows the patient what their body is doing, and they use that information to improve movement or function

• Visualization

• Relaxation training

• Postural education

• Sports-specific training

• Therapeutic exercise

ADJUNCTIVE TECHNIQUES OFTEN USED WITH BIOFEEDBACK

Biofeedback

refers to techniques that give a person information about their own physiological (body functions) or biomechanical (movement-related) processes. The goal is to improve self-awareness and control of a specific, targeted process

motor learning and operant conditioning

biofeedback was used for musculoskeletal conditions, based on the principles of:

HEART RATE MONITOR

common example of biofeedback.They give real-time feedback that helps users adjust their effort during exercise to reach their target heart rate

Direct biofeedback

produce an accurate numerical representation, provides real-time values (e.g., heart rate monitors)

Transformed biofeedback

provides signals that represent physiological activity (e.g., EMG signals represent muscle activity)

SURFACE EMG FEEDBACK

uses electrodes on the surface of the skin to detect the underlying intrinsic electrical activity of muscle tissue and converts this to an extrinsic auditory, visual, or haptic (vibration) signal that is fed back to the user

Narrow spacing

more superficial and specific

Wider spacing

broader sampling, but less specific

microvolts (μV)

The muscle’s electrical signals are measured in

GAIN SETTING

• determines the sensitivity of a device or its ability to reflect various levels of ionic activity.

• Typical range: 1 to 2000 μV

2 μV

Resting muscle value

20–30 mV

Healthy contraction

need less amplification (lower gain)

Stronger muscles

high gain setting

A_______ means the device picks up even tiny muscle activity—great for weak muscles

low gain setting

A _______ is used when the muscle is strong and doesn’t need much amplification to produce a signal.

adjust gain = “shaping”

• _______ as patient improves or struggles

• This gradual adjustment is called ______

• Helps optimize training and rehabilitation

Above threshold

goal to increase activity (facilitation)

Below threshold

goal to decrease activity (inhibition)

arthrogenic muscle inhibition (AMI)

Normal muscle function is inhibited in the presence of pain and swelling after injury or surgery(e.g., ACL repair) This may be a result of decreased excitability of the associated primary motor cortex, a phenomenon commonly referred to as _________

ARTHROGENIC MUSCLE INHIBITION (AMI)

• reduced excitability after injury/pain/swelling

• Leads to atrophy, weakness, long-term disability if left untreated.

• EMG biofeedback can help reverse _____ by using attentional strategies and improving activation timing and recruitment

↑ MVIC (maximal voluntary isometric contraction)

↓ Motor unit recruitment latency

↑ ROM, function

short term benefits of neuromascular facilitation(up training)

based on exercise dose + specificity of training

long term benefits of neuromascular facilitation(up training

reduce muscle tone or activity

goal of down training

• With relaxation training

• Postural retraining

• Pain, hypertonicity, ROM improvement

Neuromuscular Inhibition (Down Training) Common Uses

Improve timing + pattern of muscle activity

Neuromuscular Coordination Goal

• Functional movements (e.g., gait)

• Sports or fine-motor tasks

• Neuro rehab (stroke, CP, etc.)

  Emphasis is on timing and recruitment, not just strength or tone

Neuromuscular Coordination used for:

upper extremity motor recovery

Strong evidence supports EMG biofeedback for _________

• reduce footdrop,

• improve shoulder stability, and

• enhance hand function.

EMG biofeedback helps _______

chronic (>3 months post-stroke).

Most effective when stroke is______

• Generally safe, no direct contraindications when used properly

• Avoid when muscle activation may worsen the condition

• Acute Inflammatory Conditions

• Pregnancy

• Bladder or Vaginal Infection

contraindications

-History of adhesive allergy

-Recent surgery

-Fractures or muscle strains

Precautions

• Skin irritation (from electrodes)

• Increased soreness if overused

• Watch for fatigue or discomfort

• EMG should not make the condition worse —if it does, reassess.

POSSIBLE ADVERSE EFFECTS