Electrotherapy in Physiotherapy: TENS, Ultrasound, Laser & IFT Explained

Electrotherapy in Physiotherapy: Complete Modality Guide

Electrotherapy uses electrical energy, sound waves, or electromagnetic radiation to reduce pain, accelerate tissue healing, and restore function.

1. TENS (Transcutaneous Electrical Nerve Stimulation)

Delivers low-voltage electrical pulses. Activates gate control mechanism. Parameters: 80-120 Hz (conventional) or 2-4 Hz (acupuncture-like). Best for chronic pain, neuropathy, post-operative pain. Evidence: 30-50% pain reduction.

2. IFT (Interferential Therapy)

Two medium-frequency currents (4000 Hz) cross deep in tissue. Advantages: deeper penetration (5-8 cm), more comfortable. Best for deep joint pain, muscle spasm, oedema.

3. Therapeutic Ultrasound

Sound waves (1 MHz or 3 MHz) produce thermal and non-thermal effects. Thermal: deep heating increases blood flow 2-3x. Non-thermal: microstreaming accelerates cellular repair. Best for tendon injuries, ligament sprains, scar tissue.

4. Class-IV Laser Therapy

High-power infrared light (808 nm, 10-30 watts) penetrates 5-8 cm. Photobiomodulation stimulates ATP production. Best for tendinopathy, chronic pain, post-surgical inflammation. Evidence: 80% improvement in 6-8 sessions for tendinopathy.

5. NMES (Neuromuscular Electrical Stimulation)

Electrical impulses stimulate motor nerves causing muscle contraction. Best for muscle re-education post-stroke, quadriceps strengthening post-knee surgery, preventing atrophy.