Diathermy Flashcards
Diathermy Definition
Use of shortwave and microwave electromagnetic energy to heat deep soft tissues and large surface areas while minimally heating superficial tissues
Physical Properties of Diathermy
Shortwaves- frequency range–1.8 to 30 MHz
Continuous SWD (CSWD): heating deep tissues Pulsed SWD (PSWD): pulsing for a thermal physiological effects
Diathermy Parameters
Three shortwave frequency bands FCC approved
27.12 MHz
Most common frequency = 27.12 MHz,
broadest band
easiest, and least expensive to generate
Wavelength: 11m
Temperature determined by
Field intensity –electrical/magnetic
Tissue type-muscle, fat, bone
Duty cycle- continuous vs. pulsed
Distance from patient-temp change decreases with distance
Physiological effects of Deep Heating via Diathermy
Vasodilation Increased rate of nerve conduction Elevation of pain threshold Alteration of muscle strength Acceleration of enzymatic activity- Increased soft tissue extensibility
Indications
Heating jt capsules before stretching or mobilizations
Enhancement of soft tissue healing
Musculoskeletal Disorders-dec joint stiffness, muscle guarding, pain
Areas of treatment that are uneven or irregular (shoulders, hips, ankles)
Bursitis
Degenerative joint disease
Decreased collagen extensibility
Peripheral nerve regeneration
Effect of Thermal Continuous SWD
Effect:
Large deep tissue healing
Goal: elevate deeper tissue temp to 104-113 F
Non Thermal Pulsed SWD Effect
Effect:
Increased micro vascular perfusion
Altered cell membrane function and cellular activity
Pain,edema
Limbs in casts
Inc microvasc perfusion- inc local circulation,. Tissue oxygenation, nutrient availability, inc process of phagocytosis
Clinical Application of Continuous SWD
Pain control
Accelerated tissue healing
Decreased joint stiffness
Increased joint ROM
Clinical Application of Pulsed SWD
Control of pain and edema
Soft tissue, nerve, and bone healing
Improvement of osteoarthritis symptoms
Diathermy Thermal Effects caused by
Increase in random motion and kinetic energy among atoms, ions and molecules
Eddy currents created in the tissues
Greatest current flow through the tissues with least resistance (fat) and allows for heating in tissues with high water and electrolyte content (muscle)
Mechanical Effects caused by
Dipole rotation occurs in the water molecules and collide with other molecules increasing heat generation
Nonpolar molecules (ie Na+, K+, Cl-) oscillate back and forth and create a small amount of friction
General Contraindications for all types of Units
All diathermy Units (MWD, SWD, PSWD) Implanted or transcutaneous stimulators, including pacemaker Pregnancy
Thermal Diathermy Contraindications
Metal Implants Malignancy Eyes Testes Growing epiphyses
Non Thermal Diathermy Contraindications
Directly over deep tissue/internal organs
As a substitute for conventional therapy for edema and pain-
use in conjunction with compression, immobilization, meds
Metal implants-confirm with x-ray, closed loop plates and screws
