Release time：2024-08-15 16:30
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Biological effects of low-frequency electrotherapy:
Excite nerves and muscles: The most suitable current frequency for causing single muscle contraction is 1~10Hz, and the most suitable current frequency for causing complete muscle contraction is 50Hz
Promote blood circulation: Mechanism → Inhibit sympathetic nerves: Low-frequency pulse current acts on sympathetic ganglia, which can cause inhibition and dilate blood vessels. The low-frequency current frequency for exciting sympathetic nerves is 1~10Hz. The low-frequency current frequency for reducing the excitability of sympathetic nerves is 100Hz.
Analgesia: The frequency of 100Hz has a better analgesic effect and dissipates inflammation.
Classification of low-frequency electrotherapy
Induction electrotherapy
Electroexcitation therapy
Intermittent electrotherapy
Transcutaneous nerve electrical stimulation
Neuromuscular electrical stimulation
Functional electrical stimulation
Induction electrotherapy:
Definition: Also known as Faraday current, the method of using this current to treat diseases is called induction electrotherapy.
Traditional induction electricity (60~80Hz): generated by the induction coil, the peak part of the pulse wave is a high-pointed triangle, and there is a low-level negative wave without therapeutic effect.
New induction electricity (50~100Hz): generated by electron tubes or transistors, the waveform is a high-pointed triangle, without negative waves.
Therapeutic effect:
Excite nerves and muscles, promote local blood circulation and prevent adhesions.
Analgesia: Reduce the excitability of sensory nerves when stimulated in small doses. Inhibit other pathological excitability of the cerebral cortex when stimulated in large doses.
Clinical application:
Indications: disuse muscular atrophy, muscle tension, gastroptosis, slow constipation, hysterical paralysis, hysterical aphasia.
Contraindications: Spastic paralysis, the rest is the same as direct current therapy.
Operation method:
Fixation method: Two lead sheet electrodes and pads are placed opposite to each other on the affected part or at both ends of the affected muscle.
Single point method: A handle electrode or a point electrode with a diameter of 3cm and a pad are used as the main pole, tightly pressed on the motor point of the patient's muscle, and a 100cm² electrode and pad are used as abdominal muscles, placed at the proximal end of the main pole.
Electroexcitation therapy:
Definition: Electroexcitation therapy is a method of treating diseases by combining the use of induced current and direct current stimulation to cause secondary inhibition after high excitement.
Therapeutic effect:
Convert neurosis dominated by central nervous system excitation process into inhibition and improve sleep. The reflex muscle tension after muscle sprain turns into relaxation after strong contraction, and the pain relief is to increase the excitability of the cutaneous nerve distribution area of sensory impairment and restore sensation.
Clinical application: Indications: lumbar muscle sprain, lateral femoral cutaneous neuritis, neurosis.
Precautions: Before treatment, inform the patient of the possible strong stimulation. When using strong direct current stimulation above L3, it should be stimulated on both sides of the spine separately, and the strong direct current should not cross the spinal cord. The electrode should not be placed in the precordial area.
Intermittent electrotherapy:
Definition: Intermittent current is a pulse current formed by superimposing 50Hz sinusoidal alternating current on direct current after rectification. The method of using this current to treat diseases is called intermittent electrotherapy.
Therapeutic effect:
Analgesia: Intermittent current has better analgesic effect than direct current and induction electricity. The analgesic effect of intermittent rising wave and sparse and dense wave is the strongest, followed by dense wave and sparse wave.
Promote local blood circulation and dissipate edema: dense wave, sparse-dense wave
Excite nerves and muscles: intermittent wave, undulating wave.
Clinical effects: Indications: neuralgia, sprain, tennis elbow, periarthritis of shoulder, myofibromyitis, temporomandibular joint dysfunction, Raynaud's disease.
Transcutaneous electrical nerve stimulation (TENS):
The treatment method of using low-frequency pulse current of a certain frequency and a certain wave width to act on the body surface to stimulate sensory nerves to achieve analgesia is called transcutaneous nerve stimulation. Most transcutaneous electrical nerve stimulation devices output single or biphasic asymmetric square waves or triangle waves.
Therapeutic effects:
Relieve various acute and chronic pains; the most suitable current frequency for exciting nerve root fibers is 100Hz, and the square wave with a wave width of 100μs
Pain caused by peripheral circulation disorders should be treated with needle-like type (acupuncture type)
Promote local blood circulation
Accelerate fracture healing
Accelerate wound healing
Indications: postoperative wound pain, neuralgia, sprains and contusions, myalgia, joint pain, headache, stump pain after amputation, phantom pain, labor contraction pain, cancer pain, fractures, slow wound healing, etc.
Neuromuscular electrical stimulation therapy:
The method of using low-frequency pulse current to stimulate nerves and muscles to cause muscle contraction is called neuromuscular electrical stimulation therapy.
Therapy to stimulate denervated muscles is called denervated muscle electrical stimulation therapy, also known as electric gymnastics therapy.
Lower motor neuron damage or disease caused muscle denervation.
Therapy to stimulate spastic muscles and antagonistic muscles is called spastic muscle electrical stimulation therapy.
Spastic paralysis caused by upper motor neuron disease or damage.
A low-frequency pulse electrotherapy device that can output triangular waves and square waves is used, with a current frequency of 0.5~100Hz
Square waves have the effect of exciting normal and denervated muscles
The adaptability of denervated muscles is lower than that of normal muscles. When performing electrical stimulation, a triangular wave with a low intensity change rate is often required, which will only cause contraction of the diseased muscles and avoid stimulating normal muscles and sensory nerves
Operation method-electrode placement method:
Monopolar method: The cathode is placed on the motor point of the affected muscle, and the anode is placed on the back of the neck (upper limbs) or lumbar sacral region (lower limbs)
Bipolar method: The proximal electrode is the anode and the distal electrode is the cathode.
Functional electrical stimulation therapy (FES):
The treatment method of using electric current to stimulate organs or limbs that have lost their functions or abnormal functions to replace or correct the lost functions of organs or limbs with the immediate effects produced is called functional electrical stimulation therapy.
Types:
Artificial pacemaker - compensates for heart function
Stimulates phrenic nerve - breathing
Stimulates bladder-related muscles - improves urination
Clinical application:
Indications: Standing and walking disorders and hand dysfunction after stroke, spinal cord injury and cerebral palsy
Contraindications: People with pacemakers are prohibited from using functional electrical stimulation of other parts. This therapy is not suitable for people with unconsciousness, limb bone and joint contracture deformity, and lower motor neuron damage and abnormal nerve reactivity.