Light, Biofeedback, & Combo US E-stim

What does LASER stand for?

Light amplification by stimulated emission of radiation

Monochromatic Laser

Single wavelength of light

Coherent Laser

All waves in phase with each other

Directional Laser

Parallel waves in same direction 

Which grades of lasers are dangerous?

• Class 3B → LLLT (bad for eye)

• Class 4 → HILT, surgical lasers (skin burns and eye injury)

Low-Level Laser Therapy (LLLT)

• Most widely accepted

• Non-thermal modality

• Effects are through photochemical responses

Tissue Healing (theory)

• Stimulates ATP and RNA production 

• Promotes collagen production 

• Modulates inflammation, which may decrease pain associated with inflammation 

• Inhibits bacterial growth 

• Promotes vasodilation 

What are indications for laster therapy?

• MSK conditions (tendinopathy, MPS, fibromyalgia)

• Pain management

• Neurological conditions (carpal tunnel, CRPS, diabetic peripheral neuropathy)

• Wound healing

What are contraindications for laser therapy?

• direct eye exposure

• active malignancy

• active hemorrhage

• open growth plates

• over thyroid or endocrine glands

• pregnancy

What are precautions for laser therapy?

• impaired sensation/mentation

• indirect eye exposure 

• skin color (darker absorbs more energy)

What are some adverse effects of laser therapy?

• transient tingling

• mild erythema (redness)

• skin rash

• burning sensation

• increased pain or numbness

• retinal damage with exposure to eyes

• burns

Laser Dosing

• Depends on target tissue, condition, size of area, target dosage, & treatment time

• Stronger laser → shorter treatment time

• Follow instructions it comes with!

Steps for Laser Application

1. Explain procedure, include purpose & what pt should expect

2. Clear contraindications 

3. Examine and cleanse skin

4. Select appropriate energy density 

5. Put on protective eyewear!

6. Apply applicator with firm pressure keeping perpendicular to skin 

7. Begin light output & keep applicator in place throughout tx

8. Examine skin afterwards for adverse reactions 

Light-Emitting Diodes (LEDs)

• Produce monochromatic or polychromatic light (visible + infrared)

• Lower coherence & directionality than lasers

• Power output → 5 - 40 mW; up to 90 mW

• Usually arranged in clusters/pads with 20 - 30 diodes

• Longer tx time than lasers → allows higher total doses but may cause skin warming

• Physiological effects mostly theoretical; limited research

• Indications/contraindications/precautions similar to laser with higher burn risk

Electromyographic (EMG) Biofeedback

• Monitoring, detection, or assessment of skeletal muscle activity

• Can guide increasing or decreasing activity, increase NM control, improve function, decrease pain

• Electrodes = specifically made to detect electrical activity of muscle

• 1 electrode per channel

EMG Biofeedback Threshold

Level of muscle activity the patient is able to reach, whether it is increased or decreased activity 

EMG Biofeedback Facilitation

• Increase volitional activation of muscle

• Patient increases muscular activity to threshold target, audio, or video feedback is provided

• Patient is able to increase volitional activity → sensitivity can be decreased and electrode placement can be narrowed to focus on specific areas

EMG Biofeedback Inhibition

• Decrease volitional activation of muscle 

• Patient decreases muscular activity to threshold target, audio, or video feedback is provided

• Patient can relax/quiet highly active muscle → sensitivity may be increased & electrode placement widened to assess muscle activity 

Combo US & E-stim

• Unit gives US & E-stim at same time through transducer & electrode pad placed in different area

• Provides benefit of both modalities