Physical Modalities: Electrotherapy, Cryotherapy, Massage Therapy

Physical modalities have been a valuable therapeutic tool in rehabilitation for many years. Traditionally, they include cryotherapy, thermotherapy, traction, transcutaneous electrical nerve stimulation (TENS), manual massage, phonophoresis, and iontophoresis.

Their mechanism of action involves the transmission of low, medium, and high frequency energy to the tissues in order to stimulate them in ways not achievable through voluntary patient activity or manual therapy techniques. Often, physical modalities serve as a complementary part of a comprehensive therapeutic plan. They allow therapists to control symptoms and facilitate the use of other therapeutic techniques to achieve faster functional goals. The key to their effectiveness lies in the use of high-quality equipment and the understanding of their indications and parameters by a properly trained therapist.

Essential factors in their use include accurate diagnosis, precautions, choice of modality, treatment area, intensity, temperature range, settings, frequency, duration, goals of the treatment, and the date of re-evaluation.

A brief overview of the clinical role of the most commonly used modalities follows:

Cryotherapy:

Application is limited to superficial treatment. Its physiological actions include inflammation control via vasoconstriction, muscle relaxation by reducing the stretch reflex through suppression of Ia fiber contraction, and analgesia by slowing nerve conduction velocity through inhibition of C and Aδ fibers. Contraindications include ischemia, skin anesthesia, severe hypertension, and cold-sensitive conditions (e.g., Raynaud’s syndrome, cryoglobulinemia).

Thermotherapy:

The therapeutic temperature range is 40–45°C, applied for 5–30 minutes. Superficial heat reaches a depth of 1–2 cm; deep heat reaches 3.5–8 cm. Indicated for pain reduction, muscle spasm relaxation, contracture management, improved vascular circulation, enhanced tissue healing, increased collagen extensibility, and tissue temperature elevation.

Heat transfer methods include conduction (e.g., hot packs, paraffin bath), convection (e.g., whirlpool, moist air), and conversion (e.g., infrared radiation, ultrasound, shortwave diathermy, microwave diathermy). Infrared penetrates ~2 cm; ultrasound 3.5–8 cm, with optimal effects at the bone–tissue interface. Ultrasound frequency ranges from 0.8–1.1 MHz, intensity 0.5–4 W/cm², treatment area ~100 cm², and duration 5–8 minutes. Shortwave diathermy penetrates 4–5 cm and preferentially heats adipose over muscle tissue (typical frequency: 27.12 MHz). Microwave diathermy has shallower penetration and is used less frequently.

Contraindications: acute hemorrhage, blood dyscrasia, malignancy, sensory deficits, ischemia, skin atrophy. Ultrasound should not be applied near fluid-filled cavities (e.g., eye, uterus), pacemakers, post-laminectomy, or prosthetic joints. Shortwave diathermy is contraindicated in children (immature epiphyses), metallic implants, contact lenses, and pregnancy. Microwave diathermy should not be used on the eyes due to cataract risk.

Traction:

Cervical traction: 20–30 pounds of force are recommended, with 10 pounds overcoming head weight. The intervertebral angle is ~30° flexion. Extension is not recommended due to vertebrobasilar insufficiency.
Lumbar traction: 26% of body weight is needed to overcome friction in supine position with flexed hips and knees; an additional 25% is needed for vertebral separation. Split-bed traction tables reduce friction. Though commonly recommended for lumbar disc herniation and radiculopathy, evidence is inconclusive.

General contraindications: ligamentous instability, osteomyelitis, discitis, spinal tumors, severe osteoporosis.
Cervical-specific: vertebrobasilar insufficiency, rheumatoid arthritis, median-line disc herniation, acute conditions.
Lumbar-specific: restrictive lung disease, pregnancy, peptic ulcers, aortic aneurysm, hemorrhoids, cauda equina syndrome.

Transcutaneous Electrical Nerve Stimulation (TENS):

Mechanism: Based on the “gate control theory” (Melzack & Wall), stimulating large myelinated Aβ and Aγ fibers inhibits the pain-conducting Aδ and C fibers via interneurons in the substantia gelatinosa.
Conventional/high-frequency TENS (50–100 Hz): low-intensity, short-duration pulses.
Acupuncture-like TENS: low-frequency (1–4 Hz), higher intensity, possibly uncomfortable; β-endorphin release may contribute to pain relief.

Contraindications: use near pacemakers, uterus, or carotid sinuses.
Indications: muscle relaxation, prevention/slowing of disuse atrophy, improved blood flow, muscle re-education, chronic or post-traumatic pain management.

Massage Therapy:

Western techniques: effleurage (stroking), petrissage (kneading), tapotement (percussion), Swedish (combined). Deep friction massage is used to break down adhesions in chronic injuries. Myofascial release targets soft tissue restrictions via sustained pressure.
Eastern techniques: acupressure, Shiatsu.
Absolute contraindications: malignancy, deep vein thrombosis, atherosclerotic plaques, infected tissue.
Relative contraindications: immature scar tissue, bleeding disorders (anticoagulants), calcified soft tissues, skin grafts.

Phonophoresis:

Topical medications (e.g., steroids, anesthetics) are mixed with a coupling medium and delivered using ultrasound. Indications include osteoarthritis, tendinitis, tenosynovitis, bursitis, contractures, sprains, tissue injuries, neuromas.

Iontophoresis:

Electric currents are used to deliver medications through biological membranes into symptomatic areas, avoiding systemic side effects.