This document discusses the basic physics and parameters of electrical currents used in electrotherapy. It explains that electrical currents are carried by the movement of electrons and ions through conductive materials. The key parameters that determine a current's physiological effects are its waveform, amplitude, pulse duration, frequency, and modulation. Sinusoidal, rectangular, and triangular waveforms are described. Currents can cause muscle contraction, alter tissue healing, and relieve pain by interacting with nerves and tissue on the segmental, systemic and cellular levels. The type of response depends on the current parameters and tissue stimulated.
The document discusses galvanic currents, including a brief history where Luigi Galvani first showed that electric current caused frog legs to twitch. It defines direct current (DC) as electrical current that flows in one constant direction, as opposed to alternating current (AC) which reverses direction. The document describes modifications to DC including interrupted DC where current flows and ceases at regular intervals. It discusses waveform characteristics like duration and frequency, and different types of interrupted DC waveforms including rectangular, triangular, trapezoidal, saw tooth, and depolarized.
The document discusses electrotherapy and faradic current. Faradic current is a type of pulsed current used in electrotherapy, with pulse durations between 0.1-1 msec and frequencies of 50-100 Hz. It stimulates motor nerves, causing contraction of muscles supplied by the nerve. Faradic current is used to facilitate muscle contraction inhibited by pain, for muscle re-education after injury or disuse, and to prevent or loosen adhesions after injury. The document outlines the physiological effects and proper application of faradic current, including identifying motor points and using small electrodes over muscles.
Different types of low frequency currents.pdfeyobkaseye
Electrotherapy uses low-frequency electric currents to stimulate the peripheral nervous system and control pain or cause muscle contraction. There are three main types of currents used: direct current, alternating current, and pulsed current. Direct current flows in one direction, alternating current changes direction continuously, and pulsed current consists of short bursts of current separated by intervals. The effects of electric currents depend on their characteristics like amplitude, frequency, pulse width, and rate of rise. Lower amplitudes preferentially stimulate sensory nerves while higher amplitudes can recruit motor nerves and cause muscle contraction or pain. Short pulse widths allow selective stimulation of motor and sensory fibers.
The document discusses interrupted direct current (IDC), describing its characteristics such as pulse duration, interphase, on and off times, and effects when used to stimulate nerves and muscles, causing contractions; it also provides examples of using IDC to treat facial nerve damage by reeducating muscles to improve expression.
Physiological and therapeutic uses of low frequency(F/G) currentsThangamani Ramalingam
This document provides a history of electrical stimulation and its applications from 420 BC to modern times. It discusses types of electrical stimulators, how stimulation works at the cellular and tissue levels, and applications such as muscle contraction, tissue regeneration, pain management, and more. The basic model of electrotherapy is described involving generator, electrodes, and tissue. Parameters for different treatment applications are outlined including muscle re-education, strengthening, range of motion, and denervated muscle stimulation. Safety considerations and contraindications are also covered.
Electrotherapy uses electric currents to treat various musculoskeletal conditions. It can be used for pain management, improving joint mobility and muscle function, enhancing wound healing, and reducing edema. Low, medium, and high frequency currents, as well as microcurrents and pulsed electromagnetic fields, are used for purposes like muscle stimulation, nerve regeneration, and reducing inflammation. Contraindications include recent wounds or fractures. Electrotherapy modalities aim to accelerate recovery from injuries and postoperative rehabilitation.
Transcutaneous electric nerve stimulation (TENS) is a non-invasive method of pain relief that uses electric currents to stimulate nerves for pain relief. There are different types of TENS including conventional/high frequency TENS, acupuncture/low frequency TENS, burst TENS, and brief/intense TENS, each with different parameters and purposes. TENS can be used to treat both acute and chronic pain conditions by targeting areas like trigger points, dermatomes, and acupuncture points. Proper electrode placement and dosage are important to provide pain relief while avoiding risks or contraindications for certain medical conditions.
The document discusses galvanic currents, including a brief history where Luigi Galvani first showed that electric current caused frog legs to twitch. It defines direct current (DC) as electrical current that flows in one constant direction, as opposed to alternating current (AC) which reverses direction. The document describes modifications to DC including interrupted DC where current flows and ceases at regular intervals. It discusses waveform characteristics like duration and frequency, and different types of interrupted DC waveforms including rectangular, triangular, trapezoidal, saw tooth, and depolarized.
The document discusses electrotherapy and faradic current. Faradic current is a type of pulsed current used in electrotherapy, with pulse durations between 0.1-1 msec and frequencies of 50-100 Hz. It stimulates motor nerves, causing contraction of muscles supplied by the nerve. Faradic current is used to facilitate muscle contraction inhibited by pain, for muscle re-education after injury or disuse, and to prevent or loosen adhesions after injury. The document outlines the physiological effects and proper application of faradic current, including identifying motor points and using small electrodes over muscles.
Different types of low frequency currents.pdfeyobkaseye
Electrotherapy uses low-frequency electric currents to stimulate the peripheral nervous system and control pain or cause muscle contraction. There are three main types of currents used: direct current, alternating current, and pulsed current. Direct current flows in one direction, alternating current changes direction continuously, and pulsed current consists of short bursts of current separated by intervals. The effects of electric currents depend on their characteristics like amplitude, frequency, pulse width, and rate of rise. Lower amplitudes preferentially stimulate sensory nerves while higher amplitudes can recruit motor nerves and cause muscle contraction or pain. Short pulse widths allow selective stimulation of motor and sensory fibers.
The document discusses interrupted direct current (IDC), describing its characteristics such as pulse duration, interphase, on and off times, and effects when used to stimulate nerves and muscles, causing contractions; it also provides examples of using IDC to treat facial nerve damage by reeducating muscles to improve expression.
Physiological and therapeutic uses of low frequency(F/G) currentsThangamani Ramalingam
This document provides a history of electrical stimulation and its applications from 420 BC to modern times. It discusses types of electrical stimulators, how stimulation works at the cellular and tissue levels, and applications such as muscle contraction, tissue regeneration, pain management, and more. The basic model of electrotherapy is described involving generator, electrodes, and tissue. Parameters for different treatment applications are outlined including muscle re-education, strengthening, range of motion, and denervated muscle stimulation. Safety considerations and contraindications are also covered.
Electrotherapy uses electric currents to treat various musculoskeletal conditions. It can be used for pain management, improving joint mobility and muscle function, enhancing wound healing, and reducing edema. Low, medium, and high frequency currents, as well as microcurrents and pulsed electromagnetic fields, are used for purposes like muscle stimulation, nerve regeneration, and reducing inflammation. Contraindications include recent wounds or fractures. Electrotherapy modalities aim to accelerate recovery from injuries and postoperative rehabilitation.
Transcutaneous electric nerve stimulation (TENS) is a non-invasive method of pain relief that uses electric currents to stimulate nerves for pain relief. There are different types of TENS including conventional/high frequency TENS, acupuncture/low frequency TENS, burst TENS, and brief/intense TENS, each with different parameters and purposes. TENS can be used to treat both acute and chronic pain conditions by targeting areas like trigger points, dermatomes, and acupuncture points. Proper electrode placement and dosage are important to provide pain relief while avoiding risks or contraindications for certain medical conditions.
Electrical stimulation is used both diagnostically and therapeutically for muscles and nerves. Diagnostic tests measure the rheobase, chronaxie, and create strength-duration curves to determine if a muscle is innervated, denervated, or partially denervated. Therapeutically, neuromuscular electrical stimulation is used to prevent muscle atrophy and decrease spasms by causing asynchronous muscle contractions, though it must be supplemented with voluntary strength training. The optimal stimulation parameters vary but generally include a pulse duration of 300-400 microseconds, frequency of 20-100 Hz, and a duty cycle sufficient to generate force without causing fatigue.
Interrupted direct current (IDC) involves delivering unidirectional current pulses separated by intervals of no current. The pulses can have different durations, frequencies, rise/fall times, and waveforms (rectangular, trapezoidal, triangular, sawtooth). IDC is used therapeutically for sensory stimulation, pain relief, accelerating healing, and muscle stimulation. It works on nerves and muscles depending on pulse duration and intensity. Techniques like labile and group stimulation are used to target all muscle fibers. IDC has physiological effects like hyperaemia and contraindications like metal implants or risk of injury.
High voltage pulsed galvanic stimulation (HVPGS) is a form of electrical stimulation using very brief high voltage pulses to stimulate nerve and muscle fibers. HVPGS uses pairs of pulses lasting 0.1 milliseconds with peak currents of 2-2.5 amps applied at a frequency of 2-100 Hz. The brief pulses allow the current to pass easily through tissue. HVPGS is used to strengthen muscles, reduce pain, and aid wound healing by increasing blood flow and reducing edema. The document provides details on the parameters and generator of HVPGS and discusses its various applications.
This document provides information about a physical agents and electrotherapy lecture for fifth semester Doctor of Physical Therapy students. It includes course details, objectives, assessment criteria, and an introduction to electrotherapy, physical agents, and the basics of currents including classification. Specifically, it defines electrotherapy and physical agents, reviews the basics of current, charge, polarity, voltage and frequency, and classifies currents as direct current, alternating current, pulsed current, and by frequency as high, medium, and low.
13.2 Physiological effects of Massage.pptxalpadhanani
Massage has many physiological effects on the body. It increases venous and lymphatic flow, improving circulation. It also increases arterial blood flow through the release of vasodilators and activation of the axon reflex. Other effects include increased blood cell counts; improved nutrient exchange; accelerated metabolism; enhanced mobility of soft tissues; modulation of the nervous, respiratory, and immune systems; and psychological relaxation. Overall, massage provides benefits like reduced fluid stagnation, improved removal of waste, and increased general well-being.
The document provides information on different types of low frequency therapeutic currents, including:
1) Faradic current, which is a short-duration interrupted current ranging from 0.1-1 msec at 50-100 Hz, used to produce near normal muscle contraction and relaxation.
2) Galvanic current, which is a direct current that flows continuously in one direction, and an interrupted form used for denervated muscle stimulation.
3) Sinusoidal currents, which are evenly alternating 50 Hz waves similar to mains current, providing 100 pulses per second.
4) Diadynamic currents, which are variations of sinusoidal currents involving single or double-phase rectification of alternating current produced
Electric stimulation works by mimicking the natural way by which the body exercises its muscles. The electrodes attached to the skin deliver impulses that make the muscles contract. It is beneficial in increasing the patient's range of motion and improves the circulation of the body.
This document provides information about faradic current, including its nature, therapeutic and physiological effects, techniques of application, indications, contraindications, and clinical applications. It describes faradic current as an asymmetrical alternating current with a pulse duration of 0.1-1 ms and frequency of 30-100 Hz. The document discusses the effects of faradic current such as stimulation of sensory and motor nerves and reduction of swelling and pain. It outlines various methods and techniques of faradic current application for diagnostic and therapeutic purposes, as well as precautions and potential dangers of its use.
Contrast bath therapy is a series of brief, repeated immersions in water, alternating between warm and cold temperatures. Research supports the use of contrast hydrotherapy to lessen muscle fatigue and to decrease pain, swelling, and lactic acid buildup following intense exercise.
Bhaskar Health News and Medical Education is leading source for trustworthy health, medical, science and technology news and information. Providing world health information Medical Education.
Bhaskar Health News and Medical Education is dedicated to medical students, physiotherapists, doctors, nurses, paramedics, physician associates, dentists, pharmacists, midwives and other healthcare professionals.
We're committed to being your source for expert health guidance. Bhaskar Health and Medical Education.
Source : https://www.bhaskarhealth.com
Health Shop: https://www.bhaskarhealth.org
@drrohitbhaskar @bhaskarhealth
#DrRohitBhaskar #BhaskarHealth
#Health #Medical #News #Physiotherapy
Presentation on SHOCKWAVE THERAPY.
What is ESWT Or Shockwave Therapy.
MECHANISM OF ACTION Shockwave Therapy.
MEDICAL EFFECTS of Shockwave Therapy.
INDICATIONS and CONTRAINDICATIONS of Shockwave Therapy.
Some of the benefits of shockwave therapy treatment.
HOW SUCCESSFUL IS SHOCKWAVE?
Types of electrotherapeutic current (unit 6)
1. Types of electrotherapeutic current :- There are three types of current used in electrotherapeutic purpose:-
Direct current.
Alternating current.
Pulsed current/ pulsatile current.
2. Characteristic features of electrotherapeutic current:- Wave Form:-
The shape of the single pulse or cycle phases as they appear on the graph of current (voltage) versus time is called wave form.
Mainly two types of characteristics are used to describe pulsed and alternating current wave forms:-
Descriptive (qualitative) characteristics.
Quantitative Characteristics.
3. Current modulations:- Changes in current characteristics may be sequential, intermittent or variable in nature and are referred to as modulations.
Amplitude modulation:- Variations in peak amplitude of a series of pulses.
4. Burst Current:- A finite series of pulses, a finite interval of alternation current delivered at a specific frequency over a specific time interval.
Burst duration (with interruption).
Inter burst interval (without interruption).
Continuous mode (without interruption).
Ultrasound therapy uses high-frequency sound waves to treat soft tissue injuries and conditions. The document discusses the production of therapeutic ultrasound using piezoelectric crystals, its physical and physiological effects like thermal heating and non-thermal cavitation. Precautions are needed to avoid overheating tissues. Ultrasound enhances soft tissue repair and reduces pain and inflammation through thermal and non-thermal mechanisms. Common therapeutic uses include fracture healing and wound care. Proper application parameters and coupling agents are required to effectively deliver ultrasound to tissues.
Interferential therapy is a form of electrical stimulation that uses two medium frequency currents to produce a low frequency beating effect deeper in the tissues. It can provide analgesic, anti-inflammatory and muscle stimulation effects. IFT is applied using electrode pads or probes placed on the skin over the treatment area. Parameters like frequency, intensity, and application time can be modified based on the condition being treated. Common indications include pain, muscle spasm, edema, and post-surgical issues. Proper application and monitoring of settings is needed to provide benefit safely.
Interferential therapy is a form of electrical stimulation that uses two medium frequency currents between 4000-5100 Hz to generate low frequency interference currents between 1-100 Hz at targeted tissue depths. This allows for pain relief, muscle stimulation, increased blood flow and lymphatic drainage without the limitation of skin resistance. Electrodes are placed diagonally over the area of interest and current intensity is gradually increased until felt by the patient. Contraindications include coagulation issues, arterial disease, infections and pacemakers. Typical applications are for pain, swelling, muscle stimulation and tissue healing.
This document discusses different modalities used in low frequency electrical stimulation. It outlines various agents used including TENS, IFT, NMES, FES, faradic stimulation, iontophoresis, HVPGS, LIDC, twin peak monophasic stimulation, diadynamic therapy, H wave therapy, APS, Russian stimulation, Rebox therapy, and microcurrent therapy. It provides details on wave forms, currents, and specifications of different devices. Microcurrent therapy is described as using currents that are 1/1000th of an ampere smaller than TENS to alleviate pain, inflammation, spasm and promote healing for various injuries and conditions.
HIGH VOLTAGE PULSATING CURRENT (super imposed current)Aqsa Mushtaq
The document lists the group members working on the topic of super imposed currents. It discusses techniques for electrode placement and polarity in monopolar and bipolar formats. Contraindications that could be dangerous are listed, such as cancer, pregnancy, seizures or heart conditions. Precautions are recommended for impaired sensations, cerebral palsy, inflammation or sensitivity. Potential dangers from the currents include burns, shocks, pain, irritation and muscle soreness.
This document discusses interrupted direct current (IDC), which describes continuous unidirectional current that is interrupted to create pulses of varying duration, shape, or frequency. There are two main types of IDC pulses: rectangular wave pulses and accommodation pulses. Rectangular pulses have sudden rises and falls, while accommodation pulses gradually rise and fall in shapes like triangular, trapezoid, or sawtooth. IDC can stimulate nerves and muscles. Short pulses preferentially stimulate nerves, while longer pulses are needed to stimulate muscles at tolerable intensities. The document discusses electrotonus effects from IDC and considerations for selecting appropriate pulse durations and intensities. It concludes with indications for using electrical stimulation to produce muscle contraction without excessive fatigue.
This document discusses ultrasound and its use in physiotherapy. It begins by defining ultrasound and its frequencies. It then covers the components of an ultrasound machine, treatment parameters, transmission methods, and the properties of ultrasound like reflection, refraction and attenuation. The document outlines ultrasound's physiological effects and its therapeutic uses for conditions like soft tissue injuries and inflammation. It provides guidance on testing equipment, treatment methods, dosages, contraindications, and precautions when using ultrasound.
IFT which stands for Interferential Therapy is one of the types of electrotherapy used for the management of pain. The principle of interferential therapy is to cause two medium frequency currents of slightly different frequencies to interfere with one another. For example, if circuit A carries a current with the frequency of 4000Hz and Circuit B carry a current with a frequency of 3980 Hz, then the low frequency produced will be 20 Hz and this frequency is very useful in pain modulation. A new low-frequency current known as the beat frequency is equal to the difference in frequencies between the two medium frequency currents produced in the tissues at the point where the two currents cross.
It is basically used for the treatment of Chronic, Post Traumatic, and Post-surgical pains. The basic principle involves the utilization of effects of low frequencies (<250pps) without painful or unpleasant side effects. The major advantage of IFT is that it produces effects in the tissue, exactly where required without unnecessary and uncomfortable skin stimulation. This technique is widely used to elicit muscle contraction, promote healing and reduce edema.
Vector effect: The interference field is rotated to an angle of 450 in each direction, the field thus covers a wider area. This is useful in diffuse pathology or if the site of the lesion cannot be accurately localized.
Frequency swing: Some equipment allows a variation in the speed of the frequency swing. A rhythmic mode may be a continuous swing from 0 to 100 Hz in 5-10s and back in similar time or it may hold for 1-6s at one frequency followed by 1-6s at another frequency with a variable time to swing between the two.
Constant frequency: Some treatments may be carried out with the interference fixed at a certain frequency. Rhythmic frequency is useful if several types of tissues are to be treated at once. A variation in the frequency also overcomes the problem of tissue accommodation where the response of a particular tissue decreases with time.
WORKING PRINCIPLE: Interferential current therapy works by sending small amounts of electrical stimulation to damaged tissues in the body. The therapy is meant to boost the body's natural process of responding to pain, by increasing circulation thus produces hormones that promote healing. IFT delivers intermittent pulses to stimulate surface nerves and block the pain signal, by delivering continuous deep stimulation into the affected tissue. IFT relieves pain, increases circulation, decreases edema, and stimulates the muscles. A frequency of 100Hz may stimulate the large diameter A-beta fibers, which have an effect on the pain gate, and inhibit the transmission of small-diameter nociceptive traffic ( C and A-delta fiber), which effectively closes the gait to painful impulses. Interferential current Increases the circulation of blood thus reduces swelling.
This document discusses different types of wave forms used in electrical stimulation. It describes wave forms as the graphical representation of direction, shape, amplitude, and pulse of a current. It discusses different characteristics of wave forms including whether they are mono- or bi-phasic, their shape (such as sine, rectangular, triangular), amplitude, frequency, duration, and different methods of current modulation (continuous, interrupted, burst, ramping). The document also classifies currents based on direction of flow, frequency, voltage, and amperage. It provides details on specific types of currents including interrupted direct current, faradic type currents, and modified faradic currents.
This document discusses electrotherapy, which uses electrical energy as a medical treatment. It describes various types of electrotherapy including ultrasound and transcutaneous nerve stimulation. Electrotherapy can effectively manage pain and dysfunction when combined with manual therapy and exercise. The document outlines different classifications of electrical currents based on direction, frequency, voltage, and amperage. It also explains various waveforms, pulse characteristics, and how to select appropriate currents and impulses to stimulate denervated muscles without activating nearby innervated muscles.
Electrical stimulation is used both diagnostically and therapeutically for muscles and nerves. Diagnostic tests measure the rheobase, chronaxie, and create strength-duration curves to determine if a muscle is innervated, denervated, or partially denervated. Therapeutically, neuromuscular electrical stimulation is used to prevent muscle atrophy and decrease spasms by causing asynchronous muscle contractions, though it must be supplemented with voluntary strength training. The optimal stimulation parameters vary but generally include a pulse duration of 300-400 microseconds, frequency of 20-100 Hz, and a duty cycle sufficient to generate force without causing fatigue.
Interrupted direct current (IDC) involves delivering unidirectional current pulses separated by intervals of no current. The pulses can have different durations, frequencies, rise/fall times, and waveforms (rectangular, trapezoidal, triangular, sawtooth). IDC is used therapeutically for sensory stimulation, pain relief, accelerating healing, and muscle stimulation. It works on nerves and muscles depending on pulse duration and intensity. Techniques like labile and group stimulation are used to target all muscle fibers. IDC has physiological effects like hyperaemia and contraindications like metal implants or risk of injury.
High voltage pulsed galvanic stimulation (HVPGS) is a form of electrical stimulation using very brief high voltage pulses to stimulate nerve and muscle fibers. HVPGS uses pairs of pulses lasting 0.1 milliseconds with peak currents of 2-2.5 amps applied at a frequency of 2-100 Hz. The brief pulses allow the current to pass easily through tissue. HVPGS is used to strengthen muscles, reduce pain, and aid wound healing by increasing blood flow and reducing edema. The document provides details on the parameters and generator of HVPGS and discusses its various applications.
This document provides information about a physical agents and electrotherapy lecture for fifth semester Doctor of Physical Therapy students. It includes course details, objectives, assessment criteria, and an introduction to electrotherapy, physical agents, and the basics of currents including classification. Specifically, it defines electrotherapy and physical agents, reviews the basics of current, charge, polarity, voltage and frequency, and classifies currents as direct current, alternating current, pulsed current, and by frequency as high, medium, and low.
13.2 Physiological effects of Massage.pptxalpadhanani
Massage has many physiological effects on the body. It increases venous and lymphatic flow, improving circulation. It also increases arterial blood flow through the release of vasodilators and activation of the axon reflex. Other effects include increased blood cell counts; improved nutrient exchange; accelerated metabolism; enhanced mobility of soft tissues; modulation of the nervous, respiratory, and immune systems; and psychological relaxation. Overall, massage provides benefits like reduced fluid stagnation, improved removal of waste, and increased general well-being.
The document provides information on different types of low frequency therapeutic currents, including:
1) Faradic current, which is a short-duration interrupted current ranging from 0.1-1 msec at 50-100 Hz, used to produce near normal muscle contraction and relaxation.
2) Galvanic current, which is a direct current that flows continuously in one direction, and an interrupted form used for denervated muscle stimulation.
3) Sinusoidal currents, which are evenly alternating 50 Hz waves similar to mains current, providing 100 pulses per second.
4) Diadynamic currents, which are variations of sinusoidal currents involving single or double-phase rectification of alternating current produced
Electric stimulation works by mimicking the natural way by which the body exercises its muscles. The electrodes attached to the skin deliver impulses that make the muscles contract. It is beneficial in increasing the patient's range of motion and improves the circulation of the body.
This document provides information about faradic current, including its nature, therapeutic and physiological effects, techniques of application, indications, contraindications, and clinical applications. It describes faradic current as an asymmetrical alternating current with a pulse duration of 0.1-1 ms and frequency of 30-100 Hz. The document discusses the effects of faradic current such as stimulation of sensory and motor nerves and reduction of swelling and pain. It outlines various methods and techniques of faradic current application for diagnostic and therapeutic purposes, as well as precautions and potential dangers of its use.
Contrast bath therapy is a series of brief, repeated immersions in water, alternating between warm and cold temperatures. Research supports the use of contrast hydrotherapy to lessen muscle fatigue and to decrease pain, swelling, and lactic acid buildup following intense exercise.
Bhaskar Health News and Medical Education is leading source for trustworthy health, medical, science and technology news and information. Providing world health information Medical Education.
Bhaskar Health News and Medical Education is dedicated to medical students, physiotherapists, doctors, nurses, paramedics, physician associates, dentists, pharmacists, midwives and other healthcare professionals.
We're committed to being your source for expert health guidance. Bhaskar Health and Medical Education.
Source : https://www.bhaskarhealth.com
Health Shop: https://www.bhaskarhealth.org
@drrohitbhaskar @bhaskarhealth
#DrRohitBhaskar #BhaskarHealth
#Health #Medical #News #Physiotherapy
Presentation on SHOCKWAVE THERAPY.
What is ESWT Or Shockwave Therapy.
MECHANISM OF ACTION Shockwave Therapy.
MEDICAL EFFECTS of Shockwave Therapy.
INDICATIONS and CONTRAINDICATIONS of Shockwave Therapy.
Some of the benefits of shockwave therapy treatment.
HOW SUCCESSFUL IS SHOCKWAVE?
Types of electrotherapeutic current (unit 6)
1. Types of electrotherapeutic current :- There are three types of current used in electrotherapeutic purpose:-
Direct current.
Alternating current.
Pulsed current/ pulsatile current.
2. Characteristic features of electrotherapeutic current:- Wave Form:-
The shape of the single pulse or cycle phases as they appear on the graph of current (voltage) versus time is called wave form.
Mainly two types of characteristics are used to describe pulsed and alternating current wave forms:-
Descriptive (qualitative) characteristics.
Quantitative Characteristics.
3. Current modulations:- Changes in current characteristics may be sequential, intermittent or variable in nature and are referred to as modulations.
Amplitude modulation:- Variations in peak amplitude of a series of pulses.
4. Burst Current:- A finite series of pulses, a finite interval of alternation current delivered at a specific frequency over a specific time interval.
Burst duration (with interruption).
Inter burst interval (without interruption).
Continuous mode (without interruption).
Ultrasound therapy uses high-frequency sound waves to treat soft tissue injuries and conditions. The document discusses the production of therapeutic ultrasound using piezoelectric crystals, its physical and physiological effects like thermal heating and non-thermal cavitation. Precautions are needed to avoid overheating tissues. Ultrasound enhances soft tissue repair and reduces pain and inflammation through thermal and non-thermal mechanisms. Common therapeutic uses include fracture healing and wound care. Proper application parameters and coupling agents are required to effectively deliver ultrasound to tissues.
Interferential therapy is a form of electrical stimulation that uses two medium frequency currents to produce a low frequency beating effect deeper in the tissues. It can provide analgesic, anti-inflammatory and muscle stimulation effects. IFT is applied using electrode pads or probes placed on the skin over the treatment area. Parameters like frequency, intensity, and application time can be modified based on the condition being treated. Common indications include pain, muscle spasm, edema, and post-surgical issues. Proper application and monitoring of settings is needed to provide benefit safely.
Interferential therapy is a form of electrical stimulation that uses two medium frequency currents between 4000-5100 Hz to generate low frequency interference currents between 1-100 Hz at targeted tissue depths. This allows for pain relief, muscle stimulation, increased blood flow and lymphatic drainage without the limitation of skin resistance. Electrodes are placed diagonally over the area of interest and current intensity is gradually increased until felt by the patient. Contraindications include coagulation issues, arterial disease, infections and pacemakers. Typical applications are for pain, swelling, muscle stimulation and tissue healing.
This document discusses different modalities used in low frequency electrical stimulation. It outlines various agents used including TENS, IFT, NMES, FES, faradic stimulation, iontophoresis, HVPGS, LIDC, twin peak monophasic stimulation, diadynamic therapy, H wave therapy, APS, Russian stimulation, Rebox therapy, and microcurrent therapy. It provides details on wave forms, currents, and specifications of different devices. Microcurrent therapy is described as using currents that are 1/1000th of an ampere smaller than TENS to alleviate pain, inflammation, spasm and promote healing for various injuries and conditions.
HIGH VOLTAGE PULSATING CURRENT (super imposed current)Aqsa Mushtaq
The document lists the group members working on the topic of super imposed currents. It discusses techniques for electrode placement and polarity in monopolar and bipolar formats. Contraindications that could be dangerous are listed, such as cancer, pregnancy, seizures or heart conditions. Precautions are recommended for impaired sensations, cerebral palsy, inflammation or sensitivity. Potential dangers from the currents include burns, shocks, pain, irritation and muscle soreness.
This document discusses interrupted direct current (IDC), which describes continuous unidirectional current that is interrupted to create pulses of varying duration, shape, or frequency. There are two main types of IDC pulses: rectangular wave pulses and accommodation pulses. Rectangular pulses have sudden rises and falls, while accommodation pulses gradually rise and fall in shapes like triangular, trapezoid, or sawtooth. IDC can stimulate nerves and muscles. Short pulses preferentially stimulate nerves, while longer pulses are needed to stimulate muscles at tolerable intensities. The document discusses electrotonus effects from IDC and considerations for selecting appropriate pulse durations and intensities. It concludes with indications for using electrical stimulation to produce muscle contraction without excessive fatigue.
This document discusses ultrasound and its use in physiotherapy. It begins by defining ultrasound and its frequencies. It then covers the components of an ultrasound machine, treatment parameters, transmission methods, and the properties of ultrasound like reflection, refraction and attenuation. The document outlines ultrasound's physiological effects and its therapeutic uses for conditions like soft tissue injuries and inflammation. It provides guidance on testing equipment, treatment methods, dosages, contraindications, and precautions when using ultrasound.
IFT which stands for Interferential Therapy is one of the types of electrotherapy used for the management of pain. The principle of interferential therapy is to cause two medium frequency currents of slightly different frequencies to interfere with one another. For example, if circuit A carries a current with the frequency of 4000Hz and Circuit B carry a current with a frequency of 3980 Hz, then the low frequency produced will be 20 Hz and this frequency is very useful in pain modulation. A new low-frequency current known as the beat frequency is equal to the difference in frequencies between the two medium frequency currents produced in the tissues at the point where the two currents cross.
It is basically used for the treatment of Chronic, Post Traumatic, and Post-surgical pains. The basic principle involves the utilization of effects of low frequencies (<250pps) without painful or unpleasant side effects. The major advantage of IFT is that it produces effects in the tissue, exactly where required without unnecessary and uncomfortable skin stimulation. This technique is widely used to elicit muscle contraction, promote healing and reduce edema.
Vector effect: The interference field is rotated to an angle of 450 in each direction, the field thus covers a wider area. This is useful in diffuse pathology or if the site of the lesion cannot be accurately localized.
Frequency swing: Some equipment allows a variation in the speed of the frequency swing. A rhythmic mode may be a continuous swing from 0 to 100 Hz in 5-10s and back in similar time or it may hold for 1-6s at one frequency followed by 1-6s at another frequency with a variable time to swing between the two.
Constant frequency: Some treatments may be carried out with the interference fixed at a certain frequency. Rhythmic frequency is useful if several types of tissues are to be treated at once. A variation in the frequency also overcomes the problem of tissue accommodation where the response of a particular tissue decreases with time.
WORKING PRINCIPLE: Interferential current therapy works by sending small amounts of electrical stimulation to damaged tissues in the body. The therapy is meant to boost the body's natural process of responding to pain, by increasing circulation thus produces hormones that promote healing. IFT delivers intermittent pulses to stimulate surface nerves and block the pain signal, by delivering continuous deep stimulation into the affected tissue. IFT relieves pain, increases circulation, decreases edema, and stimulates the muscles. A frequency of 100Hz may stimulate the large diameter A-beta fibers, which have an effect on the pain gate, and inhibit the transmission of small-diameter nociceptive traffic ( C and A-delta fiber), which effectively closes the gait to painful impulses. Interferential current Increases the circulation of blood thus reduces swelling.
This document discusses different types of wave forms used in electrical stimulation. It describes wave forms as the graphical representation of direction, shape, amplitude, and pulse of a current. It discusses different characteristics of wave forms including whether they are mono- or bi-phasic, their shape (such as sine, rectangular, triangular), amplitude, frequency, duration, and different methods of current modulation (continuous, interrupted, burst, ramping). The document also classifies currents based on direction of flow, frequency, voltage, and amperage. It provides details on specific types of currents including interrupted direct current, faradic type currents, and modified faradic currents.
This document discusses electrotherapy, which uses electrical energy as a medical treatment. It describes various types of electrotherapy including ultrasound and transcutaneous nerve stimulation. Electrotherapy can effectively manage pain and dysfunction when combined with manual therapy and exercise. The document outlines different classifications of electrical currents based on direction, frequency, voltage, and amperage. It also explains various waveforms, pulse characteristics, and how to select appropriate currents and impulses to stimulate denervated muscles without activating nearby innervated muscles.
The document discusses different types of wave forms used in electrical stimulation. It describes:
1. Wave forms can be monophasic or biphasic, with direct current having one phase and alternating current having two phases. Wave forms can vary in shape from sine to rectangular to triangular.
2. Parameters like amplitude, frequency, duration, and modulation can be altered to change the physiological response. Modulation includes continuous, interrupted, burst, and ramping variations.
3. Currents are classified based on direction of flow, frequency, voltage, and amperage. Examples of specific currents discussed are interrupted direct current, faradic type currents, and modified faradic currents.
This document provides an outline for a course on electrical stimulation modalities. It discusses various types of currents including low frequency currents like Faradic and high frequency currents like shortwave diathermy. It describes different waveform shapes and characteristics of pulses used in electrical stimulation like frequency, duration, and modulation. Application techniques for different current types are outlined along with their physiological effects and therapeutic uses. Electrical reaction testing is also covered to evaluate nerve and muscle function.
This document provides an overview of low frequency currents used in electrotherapy. It discusses the history of electrotherapy including contributions from Galvani, Faraday, and others. It describes the main types of currents - direct current, alternating current, and pulsed current. Specific low frequency currents are explained such as faradic current, interrupted direct current, and TENS. The physiological effects and therapeutic indications of low frequency currents are outlined. Contraindications and precautions for electrotherapy are also reviewed.
The document provides information on the biophysical basics of electrotherapy. It defines electric current as the flow of electric charges from cathode to anode. The three main types of currents are direct current, alternating current, and pulsed current. It describes cathodal and anodal events that occur during current flow and discusses electrolysis, electrolytic dissociation, amplitude, voltage, resistance, waveform, phase, frequency, electrode placement and size. The objective is to explain the underlying biophysical principles of electrotherapy.
Frequency and Power related to electrical devices and circuitMShahidHanif1
Frequency refers to the number of times a repeating event occurs per unit of time. It is measured in hertz (Hz), with 1 Hz equaling 1 cycle per second. The frequency of an electrical current is the number of times its sine wave completes a positive-to-negative cycle per second. Higher frequencies mean more cycles occurring each second. Common frequency ranges include power lines at 50-60 Hz, audio at 15 Hz to 20 kHz, and radio from 30-300 kHz. Equipment is often designed to operate at a specific frequency, and performance is affected if it is operated at a different frequency.
Electric muscle stimulation physiotherapy.pptxRexSenior
Electrical muscle stimulation (EMS) uses electrical currents to cause muscle contractions and strengthen weak muscles. Different types of currents such as faradic and galvanic are used depending on if the muscle is innervated or denervated. A strength duration curve shows the relationship between stimulus magnitude and duration, and can indicate the state of a nerve lesion by its shape. Parameters like frequency, pulse duration, and amplitude must be set properly for safe and effective EMS treatment.
- The strength-duration curve is a graph that plots the electrical stimulus intensity against the time needed to elicit a muscle contraction. It can determine if a muscle is innervated, denervated, or partially denervated.
- The curve is generated by applying electrical stimuli of varying durations (0.01-300ms) to a muscle and recording the intensity needed to produce a minimal contraction. The shape of the curve indicates the muscle's innervation status.
- A normal curve will have all longer duration stimuli producing a response at the same intensity, while shorter durations require more intensity. Complete denervation results in a steeply rising curve requiring more intensity for all shorter durations. Partial denervation produces
1. The document discusses different types of electrical waveforms, pulse parameters, and electrode placements used in electroconvulsive therapy (ECT).
2. Key aspects of ECT include determining the seizure threshold, delivering a stimulus slightly above threshold to induce an adequate seizure, and factors that influence cognitive side effects like electrode placement and stimulus intensity.
3. Unilateral electrode placement causes fewer cognitive effects than bilateral placement but may be less effective or slower-acting in some cases. The choice depends on individual factors and need for rapid response.
The document discusses strength duration curves, which plot the electrical stimuli needed to elicit a muscle contraction over a range of stimulus durations. It describes how to perform the test and interpret the results, including details on:
- Plotting S-D curves after 20 days post-injury to assess innervation status
- The typical shape of normal, denervated, and partially denervated curves
- Additional metrics that can be measured from S-D curves like rheobase and chronaxie
- Factors that can influence the curves and what different curve patterns indicate
Introduction to Electrotherapy in Physiotherapy ProfessionPriyanka Pundir
Electrotherapy uses electrical energy for therapeutic purposes and can be classified in several ways. It includes low-frequency currents used to stimulate nerves and muscles, medium-frequency currents used for muscle re-education and pain relief, and high-frequency currents used to produce deep heat in tissues. Other areas of study are phototherapy for pain relief and healing using light, electrodiagnosis for studying electrical muscle and nerve reactions diagnostically, and biofeedback to provide voluntary control over bodily functions. Electrotherapy is an important treatment approach in physiotherapy using various electrical modalities.
Russian current is a medium frequency current delivered in bursts at 2500 Hz. It produces strong muscle contractions through synchronous motor nerve depolarization. The standard protocol is 10 contractions of 10 seconds duration, separated by 50 second rest periods, repeated over 10 cycles. It is used to improve muscle strength and reduce muscle spasm or edema by promoting muscle pumping. The key characteristics are a carrier frequency of 2500 Hz, burst frequency of 50 Hz, burst duration of 10 ms, and duty cycle of 50%.
Russian current is a medium-frequency current delivered in bursts at 2500 Hz. It produces strong muscle contractions through synchronous motor nerve depolarization. Key characteristics include a carrier frequency of 2500 Hz, burst frequency of 50 Hz, burst duration of 10 ms, and a 10/50/10 training protocol. Russian current is indicated for muscle strengthening, reducing muscle spasm and edema, such as following knee ligament injuries or surgery.
Interferential therapy involves applying two medium frequency alternating currents through tissues simultaneously. This causes the currents to interfere with each other, producing a low frequency interference current. The interference current has characteristics of low frequency stimulation and can be used therapeutically. Proper positioning of electrodes is important to ensure the interference effect occurs in the desired treatment area. Parameters like amplitude, frequency, and sweep time can be adjusted to achieve different physiological effects for various indications. Common electrode types used include plate and vacuum electrodes.
Faradic current is a short duration, interrupted electrical current used for muscle stimulation. It produces asymmetrical, biphasic waveforms. Faradic currents are surged to produce near-normal tetanic muscle contractions and relaxations. They are produced via a circuit consisting of two parallel triode valves. Faradic currents stimulate motor nerves to cause muscle contraction if the intensity is high enough. They are used diagnostically and therapeutically for conditions like muscle weakness and nerve damage. Proper application and parameters are important to achieve benefits while avoiding dangers like burns.
This document provides an overview of basic electrotherapy concepts including:
- Ohm's law defines the relationship between current, voltage and resistance. Tissue impedance varies and depends on water content.
- Nerves become hyperpolarized under the anode and more excitable under the cathode. An action potential occurs during depolarization and is followed by absolute and relative refractory periods.
- Direct current is unidirectional while alternating current changes direction. Pulsed current can be unidirectional or bidirectional. Waveform shape impacts amplitude and duration. Current intensity and tissue response depends on amplitude, frequency, phase duration and waveform.
Electrotherapy involves the use of electric currents passed through the body to stimulate nerves and muscles, chiefly in the treatment of diseases. There are different types of electric currents including direct current (DC), alternating current (AC), and pulsed current. Currents are also classified by their frequency as low, medium, or high frequency currents, with each type used for specific therapeutic applications like muscle stimulation, pain relief, or inducing deep heat.
This document provides an overview of various physical therapy methods, focusing on thermotherapy and electrotherapy. It discusses using heat/cold through conduction (packs/compresses), convection (hydrotherapy/baths), and radiation (saunas). Electrotherapy techniques covered include direct current, low-frequency alternating current for stimulation, and high-frequency currents for diathermy. Safety aspects of electric currents and their effects on tissue are also summarized.
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2. Basic physics of electrotherapy
▪ All matter is composed of atoms that contain
positively and negatively charged particles called
ions.
▪ These charged particles possess electrical energy
and thus have the ability to move about. They tend
to move from an area of higher concentration
toward an area of lower concentration.
▪ An electrical force is capable of propelling these
particles from higher to lower energy levels, thus
establishing electrical potentials.
3. Basic physics of electrotherapy
▪ Electrons are particles of matter possessing a
negative charge and very small mass. The net
movement of electrons is referred to as an
electrical current.
▪ The movement or flow of these electrons will
always go from a higher potential to a lower
potential. An electrical force is oriented only
in the direction of the applied force.
4. Basic physics of electrotherapy
▪ The unit of measurement of the electrical
current flows is the ampere (A).
▪ Amperes indicate the rate of electron flow.
▪ In therapeutic modalities, current flow is
generally described in milliamperes (mA) or in
microamperes (µA).
5. Basic physics of electrotherapy
▪ Materials that offer little opposition to current
flow are good conductors.
▪ Metals (copper, gold, silver, aluminum) are
good conductors of electricity, as are electrolyte
solutions, because both are composed of large
numbers of free electrons.
▪ Materials that resist current flow are called
insulators which contain relatively fewer free
electrons and thus offer greater resistance to
electron flow such as; Air, wood, and glass.
7. Parameters of electrical currents
Waveforms
The graphic representation of the shape, direction, amplitude,
duration, and pulse frequency of the electrical current.
▪ Sinusoidal wave; alternating current with equal energy level under
the positive and negative phase.
▪ Rectangular or square wave; Current with rapid rise, maintained
constant for the duration of stimulus and sharp drop off.
▪ Triangular wave; gradual increase and decrease of the current
intensity through prolonged duration.
▪ Spiked wave; suddenly rise up of current intensity and gradually
drop off.
9. Parameters of electrical currents
Pulse: an individual complete waveform.
Phase: portion of the pulse that rises in one direction either above
or below the baseline.
Direct current: unidirectional-monophasic current. It has only a
single pulse and phase which are the same.
Alternating current: bidirectional-biphasic current, It has two
separate phases during each individual cycle.
11. Parameters of electrical currents
Biphasic symmetrical waveform has the same shape and size for each
phase in both directions.,
Biphasic asymmetrical waveform has different shapes for each phase.
Balanced, the net charge in each direction is equal.
Unbalanced, there is a greater net charge in one phase than in the
other.
13. Parameters of electrical currents
Pulse amplitude
The amplitude of each pulse reflects the intensity of the current,
represented the tip or highest point of each phase.
Peak amplitude is determined by measuring the maximal distance to
which the wave rises above or below the baseline.
Amplitude is measured in amperes, milliamps (mA) or microamps
(µA).
14. Parameters of electrical currents
Rate of rise and decay of pulse
▪ The rate of rise in amplitude, or the rise time, refers to how
quickly the pulse reaches its maximum amplitude in each
phase.
▪ Decay time refers to the time in which a pulse goes from
peak amplitude to (0) V.
▪ The rate of rise is important physiologically because of the
accommodation phenomenon, in which a fiber that has been
subjected to a constant level of depolarization will become
unexcitable at that same intensity or amplitude.
▪ The faster the rate of rise, the greater the current's ability to
excite nervous tissue.
15. Parameters of electrical currents
▪ Pulse duration (Pulse width) is the length of time current is flowing in one
cycle.
▪ Phase duration is the length of time for a single phase to complete its rout.
▪ Pulse duration and phase duration expressed in second (sec), millisecond (ms),
or microsecond (µ sec).
▪ The current flow is off for a period of time (interpulse interval).
▪ A single pulse or phase may be interrupted by an intrapulse interval.
▪ The combined time of the pulse duration and the interpulse interval is referred to
as the pulse period.
Pulse duration
19. Parameters of electrical currents
Pulse frequency
▪ Pulse frequency indicates the number of pulses or cycles per
second.
▪ It is expressed as pulse per second (pps) or as pulse frequency in
hertz (Hz).
▪ An inverse relationship exists between the pulse frequency (pulse
rate) and an electrical current and the resistance offered by the
tissues.
▪ A current with lower pulse frequency i.e. 10 pps would meet
resistance than a current with pulse frequency 1000 pps and would
require an increased intensity to overcome the resistance.
20. Parameters of electrical currents
Pulse frequency
When stimulating muscle
contraction, the pulse
frequency plays an
important role??
21. Parameters of electrical currents
Pulse frequency
Stimulators are classified as :
▪ Low frequency generators range from one Hz to
several hundred pulses per second.
▪ Medium frequency generators have frequencies of
2500 to 10,000 Hz.
▪ High frequency generators have frequency of more
than 10,000 Hz.
22. Parameters of electrical currents
Duty cycle
▪ The duty cycle is the ratio of the amount of time the current is
flowing (ON) to the amount of time without current (OFF) and
expressed as a percentage or ratio.
▪ Duly cycles play a role in neuromuscular stimulation by preventing
muscle fatigue. Muscular stimulation is started with a 25% duty
cycle and is progressively increased as the condition improves.
On time
Duty Cycle = ـــــــــــــــــــــــــــــــــــــــ X 100%
(On time + Off time)
▪ For example, if the on time equals 10 seconds and the off time
equals 30 seconds, the duty cycle such a pattern of stimulation
would be 25%. A very different pattern of stimulation with an on
time of 5 seconds and an off time of 15 seconds yields the same
25% duty cycle.
23. Parameters of electrical currents
Current modulation
▪ The physiologic responses to electric current depend on
modulation.
▪ Modulation is alteration in the amplitude, duration, or
frequency of the current during a series of pulses or
cycles.
24. Parameters of electrical currents
Burst modulation
▪ With pulsatile currents, sets of pulses are combined. These
combined pulses are called bursts, packets, envelopes, or pulse
trains.
▪ The interruptions between individual bursts are called
interburst intervals.
▪ The time interval over which the series of pulses or cycles is
delivered is called the burst duration.
▪ The number of bursts delivered per unit of time is called the
burst frequency.
25. Parameters of electrical currents
Ramping modulation
▪ Also called surging modulation, current amplitude will
increase or ramp-up gradually to maximum then decrease
or ramp-down to zero.
▪ Ramp-up time is ⅓ of the on time.
▪ Ramping modulation is used clinically to elicit muscle
contraction and is generally considered to be a very
comfortable type of current since it allows for a gradual
increase in the intensity of a muscle contraction.
27. Parameters of electrical currents
Beat modulation
▪ Beat modulation will be produced when two
interfering alternating currents with different
frequencies are delivered through separate channels
within the same generator to produce a beat
frequency equal to the difference between the two
alternating current frequencies.
▪ The two pairs of electrodes are set up in a
crisscrossed or cloverleaf-like pattern so that the
circuits interfere with one another.
29. Physiologic responses to electrical current
▪ Electrical currents are used mainly to produce
either muscle contractions or pain relief through
effects on the motor and sensory nerves.
▪ This function is dependent to a great extent on
selecting the appropriate treatment parameters.
30. Physiologic responses to electrical current
Clinically, therapists use electrical currents for the
following reasons:
▪ To create muscle contraction through nerve or muscle
stimulations.
▪ To help in treating pain.
▪ To stimulate or alter the healing process.
▪ To drive ions beneficial to the healing process into or
through the skin.
31. Physiologic responses to electrical current
The type and extent of physiologic response to
electrical current dependent on:
▪ Type of tissue stimulated.
▪ Nature of the electrical current applied.
32. Physiologic responses to electrical current
As electricity moves through the body's
conductive medium, physiological effects of
electrical stimulation occur through different
levels:
Tissue level
▪ Skeletal muscle contraction.
▪ Tissue regeneration.
33. Physiologic responses to electrical current
Segmental level
▪ Modification of joint mobility.
▪ Muscle pumping action circulation and
lymphatic activity.
▪ Lymphatic contraction more fluid is moved
centrally.
34. Physiologic responses to electrical current
Systematic effects
▪ Release endogenous pain suppressors which act
at different levels to control pain (indirect
effect).
▪ Gate control theory: through stimulation of
certain neurotransmitters to control neural
activity in the presence of pain stimuli (direct
effect).
35. ▪ Pain is conducted either through Aδ (A delta) or C fibers.
▪ The Aδ (A delta) fibers are small myelinated, fast conductive and carry sharp pain.
▪ The C fibers are small unmyelinated, slow conductive and carry chronic dull aching
pain.
36.
37. ▪ Electrically stimulating the large sensory fibers when there is
pain in a certain area will force the central nervous system to
make the brain's recognition area aware of the electrical stimuli.
▪ As long as the stimuli are applied, the perception of pain is
diminished.
▪ Electrical stimulation of sensory nerves will evoke the gate
control mechanism and diminish awareness of painful stimuli.
▪ As long as the stimulation is causing firing of the sensory
nerves, the gate to pain should be closed.
▪ If accommodation to the electrical stimulus occurs or if the
stimulus stops, the gate is then open, and pain returns to
perception.
38. ▪ Substantia Gelatinosa (SG) in dorsal horn of spinal
cord acts as a ‘gate’ – only allows one type of
impulses to connect with the SON.
▪ Transmission Cell (T-cell) – distal end of the SON
– transmit stimulus to the brain.
▪ If A-beta neurons are stimulated – SG is activated
which closes the gate to A-delta & C neurons.
▪ If A-delta & C neurons are stimulated – SG is
blocked which closes the gate to A-beta neurons.
39. Brain
Gate (T
cells/ SG)
Pain
Electrical stimuli
▪Gate - located in the dorsal horn of the spinal cord
▪Smaller, slower n. carry pain impulses
▪Larger, faster n. fibers carry other sensations
▪Impulses (electrical) from faster fibers arriving gate 1st inhibit pain
impulses
40.
41. Muscle and nerve responses to electrical
currents
▪ Nerves and muscles are both excitable tissues
which is dependent on the cell membrane's
potential.
▪ Cell membrane potential is produced by unequal
distribution of charged ions on both sides of the
membrane.
▪ The potential difference between the inside and
outside is known as the resting membrane potential
(-70 to -90 mV), because the cell tries to maintain
this electrochemical gradient as its normal
homeostatic environment.
42. Muscle and nerve responses to electrical currents
Active transport pumps
Cell continually moves Na+ from inside cell to outside and
balances this positive charge movement by moving K+ to
the inside.
Produces an electrical gradient with + charges outside and
- charges inside.
43. Muscle and nerve responses to electrical current
Nerve depolarization
▪ To create transmission of an impulse in the nerve
tissue, resting membrane potential must be reduced
below a threshold level.
▪ Changes in the membrane's permeability then may
occur. These changes create an action potential that will
propagate the impulse along the nerve in both
directions from the location of the stimulus.
▪ An action potential created by a stimulus from
chemical, electrical, thermal, or mechanical means
always creates the same result that is membrane
depolarization.
44. Muscle and nerve responses to electrical current
Nerve depolarization
▪ Stimulus must have adequate intensity and last
long enough to equal, or exceed, membrane's
basic threshold for excitation.
▪ Stimulus must alter the membrane so that a
number of ions are pushed across membrane
exceeding ability of the active transport pumps
to maintain the resting potential, thus forcing
membrane to depolarize resulting in an action
potential.
45. Muscle and nerve responses to electrical currents
Depolarization Propagation
Difference in electrical potential between depolarized region
and neighboring inactive regions causes the electrical current
to flow from the depolarized region to the inactive region.
Forms a complete local circuit and makes the wave of
depolarization “self-propagating”.
46. Muscle and nerve responses to electricalcurrent
▪ As nerve impulse reaches
effector, organ or another
nerve cell, impulse is
transferred between the two
at a motor end plate or a
synapse.
▪ At the motor end plate, a
neurotransmitter is released
from nerve.
▪ Neurotransmitter causes
depolarization of the muscle
cell, resulting in a twitch
muscle contraction.
Depolarization Effects
Differs from voluntary muscle
contraction only in rate and
synchrony of muscle fiber
contractions!
47. Factors affecting stimulation of nerves
1.The relative diameter of the nerve:
▪ The amplitude of the current is inversely proportional to the
nerves diameter because the larger cross sectional area
provides less capacitive membrane resistance and less
current is required.
▪ Nerves with larger diameter are stimulated to threshold
before nerves with smaller diameter.
▪ Sensory nerves are stimulated first followed by motor nerves
and then pain fibers.
▪ The small C fibers carrying pain impulses need the greatest
current.
48. Factors affecting stimulation of nerves
2. The duration of the pulse:
▪ Short pulse duration allow the greatest range in stimulation
intensity for excitation of nerves.
▪ As the pulse duration is increased, less amperage is required to
stimulate nerves.
▪ Pulse duration less than 1 msec. will not be able to stimulate
denervated muscle regardless of the currents amplitude.
▪ Pain fibers are stimulated with longer pulse duration and high
intensity.
49. Factors affecting stimulation of nerves
3. The rate of rise of the pulse:
▪ Rapidly rising pulses cause nerve depolarization and if
the rate of rise is slow, the nerve accommodated to the
stimulus.
▪ Muscle fibers accommodates more slowly than nerve
fibers, so gradual pulse rise may be used.
50. Factors affecting stimulation of nerves
4. The depth of the nerves:
▪ Superficial sensory nerves receive a greater amount of
stimulation than deeply situated motor nerves.
51. Sensation levels
Subsensory level:
▪ Stimulation occurs within the output interval between the point at which
the output intensity rises from zero to the point at which the patient
receive a discrete electrical sensation.
Sensory level:
▪ An intensity that stimulates only sensory nerves.
▪ This level is found by increasing the output to the point at which a slight
muscle twitch is seen and then decreasing the output intensity by
approximately10 %.
Motor Level:
▪ An intensity that produces a visible contraction without causing pain.
Noxious Level:
▪ An intensity that stimulates pain fibers.
53. General contraindications to electrical
stimulation
▪ Unreliable patients (very young and very old).
▪ Lost or impaired sensation.
▪ Patient receiving deep X-ray therapy.
▪ Ischemia and poor circulation.
▪ Neoplasm.
▪ Open infected and/or bleeding wound.
▪ Some dermatological conditions,(dermatitis).
▪ Metal implants.
54. General contraindications to electrical
stimulation
▪ Over the eyes and the reproductive organs.
▪ Over the anterior neck region (carotid sinus) may
result in disruption of normal respiration.
▪ Near pacemakers, as it may interfere with its
function.
▪ Over the abdomen and pelvic region during
pregnancy and menstruation.
▪ Epilepsy.
55. Types of electrodes
▪ Metal Aluminum or foil plates enclosed within wet
sponge.
▪ Carbon-rubber electrodes: It should be enclosed in
wet sponge or use conducting gel.
▪ Pre gelled electrodes.
56. Electrode Placement
▪ On or around the painful area.
▪ Over specific dermatomes or myotomes that
correspond to the painful area.
▪ Close to spinal cord segment that innervates an area
that is painful.
▪ Over sites where peripheral nerves that innervate the
painful area becomes superficial and can be easily
stimulated.
57. Electrode Placement
▪ On or around the painful area.
▪ Over specific dermatomes or myotomes that
correspond to the painful area.
▪ Close to spinal cord segment that innervates an area
that is painful.
▪ Over sites where peripheral nerves that innervate the
painful area becomes superficial and can be easily
stimulated.
58. Electrode Placement
▪ Over superficial vascular structures.
▪ Over trigger or acupuncture point locations.
▪ In a criss-cross pattern surrounding the
treatment area.
▪ If treatment is not working, change electrode
placement.
60. Techniques of electrode application
Monopolar technique
▪ Use of the two electrodes:
(1) active or stimulation electrode placed over the treatment area.
(2) depressive or non treatment electrode used to complete the circuit
and placed at distant location.
▪ The depressive electrode is larger than the active electrode.
▪ The high current density focuses the electrical current under the
smaller active electrode and little or no stimulation should occur
under the depressive electrode.
▪ This technique is usually used with motor, trigger or acupuncture
point stimulation.
61. Techniques of electrode application
Bipolar technique
▪ Use of the two electrodes of equal size.
▪ Both electrodes are placed over the treatment area.
▪ Because current densities under each electrode are equal, an
equal amount of stimulation should occur under each
electrode.
▪ The electrodes should be placed over motor points within the
same muscle or muscle group or may be placed at the origin
and insertion of the same muscle.
62. Techniques of electrode application
Quadripolar technique
▪ Use of two sets of electrodes, each originating from its own channel.
▪ It may be considered the concurrent application of two bipolar
circuits.
▪ This technique could be used in:
➢ Agonist and antagonist placements as in neuromuscular
stimulation.
➢ Crossed pattern placements as in interferential current stimulation.
➢ Coplanar placements for large flat area as the back.
➢ Parallel placements as in certain transcutaneous electrical nerve
stimulation.