Modality	Description	Potential therapeutic uses	Contraindications/cautions
Ultrasound	High-frequency sound waves are used to warm superficial soft tissues or to accelerate tissue healing at the cellular level	Tendon injuries, short-term pain relief of muscle strain or spasm	Do not use near malignant tumors, nerve tissue following laminectomy, joint replacements, permanent pacemakers, thrombophlebitis, eyes, reproductive organs, acute inflammation, epiphyseal plates, or over breast implants; exemption is needed for Olympic athletes
Phonophoresis	Ultrasound is used to deliver therapeutic medications to tissue under the skin	Inflammatory conditions such as tendonitis, arthritis, and bursitis	Same as for ultrasound
Iontophoresis	Electric current is used to deliver ionically charged substances through the skin to deeper tissues	Calcific tendinopathy, inflammatory conditions, hyperhidrosis	Do not use in patients with an allergy or sensitivity to the substance applied, open wounds, or decreased sensation; do not use in the immediate vicinity of metallic implants, wires, or staples
Electrical stimulation	Generates an action potential in nerve tissue, causing a muscle contraction or altering sensory input	Muscle spasm or contusion (electronic muscle stimulation), neuropathic pain relief (transcutaneous electrical nerve stimulation)	Do not use in patients with cardiac pacemakers, known cardiac arrhythmias, or thrombophlebitis/thrombosis; do not use on the abdomen or pelvis of pregnant patients; use with caution in patients with cardiac disease, malignant tumors, open wounds, decreased sensation, or decreased mentation or communication ability
Low-level laser therapy	Absorption of photon radiation, altering cellular oxidative metabolism and decreasing prostaglandin E2 concentration	Minor musculoskeletal pain, carpal tunnel syndrome, osteoarthritis, rheumatoid arthritis	Use with caution in patients with malignant tumors or in patients taking anticoagulant, corticosteroid, or immunosuppressive drugs; do not use on the uterus of pregnant patients; patients and therapists should use safety goggles to limit eye exposure to therapeutic wavelengths