PT 8 Midterm Reviewer PDF

Electrotherapy Notes Electrodes Lesson 1. Physics of Electricity 1. Anode Shean Emmanuel Porcia – Anion is attracted to; unlike charges (Positive=N...

Electrotherapy Notes Electrodes Lesson 1. Physics of Electricity 1. Anode Shean Emmanuel Porcia – Anion is attracted to; unlike charges (Positive=Negative) attract each Atom – Minute indivisible particle that other (Anode is (+) electrode while comprise all matter Anion is (-) ions) - Universal color is Red An atom consists of an: (Hint: Anode=Anion) 1. Nucleus – central part of the atom; it is 2. Cathode composed of: - Cation is attracted to; unlike a. Proton (P=Positive charged) – it charges (Positive=Negative) determines the atomic number attract each other (Cathode is of the atom (-) electrode while Cation is (+) b. Neutron (Neu=Neutrally ions) charged) – have equal number - Universal color is Black of protons and affects the (Hint: Cathode=Cation) atomic mass (weight) - Both PROTON and NEUTRON Electricity cannot be removed from the - Form of energy; there is flow of nucleus electric charge 2. Electrons (Negatively Charged) - A Charged Body continues to - revolves in orbits around the attain neutrality. nucleus o If Negative charged it - Arranged in definite shells or would lose electrons orbits (Quantum Shell) o if Positive charged it - Can be removed from the would gain electrons. Nucleus (Can be gained or lost) o This process creates an Electric Field which is made up of lines of force - The properties of lines of force are: lines of force are straight lines of force pass more easily through conductors than through insulators lines of force concentrate nearest to another object over Neutral Atom – Equal number of protons and which they can exert an electrons influence Cation (+) ions Anion (-) ions lines of force travel Loss of electrons in gain of electrons in from negative to the atom leading to the atom leading to positive excess of protons -> excess of electrons -> Positive charge negative charge Conductors o capacitance of the object - materials which can transmit electrical current Quantity of electricity - atoms have few electrons in - Measured in Coulomb their outermost orbits since o 1 Coulomb (C) = 6.26 x they are few, they are loosely 1018 electrons charges held so that it will drift away - The higher or bigger the from the atom, facilitating the quantity of electricity passage of electron current. (Coulombs) the higher the - They are mostly metals such as Electrical Potential is. (Directly iron, copper, and the human Proportional) tissue as an exception - If you have 2 objects charged with different quantities of Non-conductors/Insulators electricity, the one with greater - Will not transmit electrical quantity of electricity has a charges/current greater power so it has greater - Atoms are firmly held and it potential of the two. will not leave the atom Capacitance - They are non-metal objects - The ability of the object to hold such as rubber, sand, and etc. an electrical charge - The capacitance of the object Electrical Charge depends on: - Occurs when the atoms have o Material – conductors Unequal numbers of electrons (metals, human skin) and protons. have greater power of o If more protons (fewer storing a charge and electrons) then it is tends to have a large more positively capacity charged. o Surface area – the o If more Electrons (Less greater, the greater the Protons) then it is more capacity negatively charged. - Inversely proportional to - As mentioned earlier, Matter electrical potential; If the with the same charge repel, but capacitance is high, the less the matter with different charges ability to move the charge attract - Unit is Farad (F) Electrical Potential Potential Difference - It is a force that causes a - There exists a difference of movement of charge to some potential in objects having distance is called Potential charges with different - Unit is Volt (V) quantities of electricity - The magnitude or how strong - If they have different quantities the potential is depends on: of electricity therefore their o quantity of electricity potential is different with which the object is (Difference of the potential). If charged there is potential difference, the electrons will flow to the  direction of negative to positive (Electron Flow). - Force producing the movement is the Electromotive Force (EMF) wherein it is measured in Volts (V). - The greater potential difference the greater the EMF (Directly - intensity or magnitude of how Proportional) strong current is the rate of - Example: flow of electrons through the (A)5V & 3V vs. (B)4V & 3V conductor per second; measured in Ampere (A) (A)Has a greater potential difference therefore Ohm’s Law it would have greater EMF compared to (B) - The magnitude or intensity(I) of the electric current varies - Electrons flow continues until directly with the EMF(E/V) and the potential of both objects inversely with the Resistance(R) are the same (If they become - EMF is directly proportional to equal = the flow of electrons the intensity. High EMF → there would stop are more number of electrons Electrical Current being moved (resulting to high - occurs when there is a flow of intensity) charged particles (generally electrons) in a conductor - Produced if there is: o a difference of potential (PD) o A conducting pathway between the points of potential difference - Some examples that can produce potential difference: o Electromagnetic Induction o Battery ▪ it has a positive and negative side (charges) ▪ It has difference in potential since Resistance one is more (+) - It opposes the flow of electrons and the other through the conductor more (-), - If a device that provides current will resistance to the flow is known flow in the as Resistor pathway - Unit Ohms (Ω)  - Electrical resistance depends on o The total resistance is the ff: less than any one of the o Material of the individual resistances 1 1 1 1 conductor o 𝑅𝑡𝑜𝑡𝑎𝑙 = 𝑅1 + 𝑅2 + 𝑅3 +⋯ ▪ Good conductor/mat erial = Less Resistance o Length of the pathway ▪ Longer the pathway = greater resistance o Cross sectional area of - When a current passes through the conductor a conductor, a portion of the ▪ Greater cross energy is converted to Thermal sectional (the Energy. more room the - Joule’s Law states that “the electrons to amount of heat produced in a pass) = conductor is proportional to the resistance square of the intensity of the lower current, the resistance and the ▪ Bigger wire time at which the current flows diameter = o Q = I2RT ; Unit is Joules lower (J) resistance ▪ Q = Heat ▪ Smaller ▪ I2 = square of diameter = intensity greater ▪ R = Resistance resistance ▪ T = Time (Easily - Greater Intensity of current Damaged or flow = more heat is produced Broken) - More resistance of current = o Temperature more heat is produced ▪ higher - Longer time = more heat is temperature produced (more Electrical Energy molecular - It is the ability of an electrical movement) = circuit to produce work by increases the creating action resistance - It supplies the power required Resistance Circuit to produce work or an action - Resistance in Series within an electrical circuit o Total resistance is equal Work to the sum of the - Dependent on the EMF and individual resistances quantity of electrons (Coulomb) o 𝑅𝑇𝑜𝑡𝑎𝑙 = 𝑅1 + 𝑅2 + 𝑅3 + ⋯ moved; Unit is Joules (J) - Resistance in Parallel o W = EMF x C  o High EMF = High Work - Observed that when a compass or Electrical Energy is brought near a conductor o More electrons moved with current, the needle of = High work or compass gets deflected because Electrical Energy of flow of electricity (Naay Power magnetic effect) - Rate of doing work; product of - Or when an electric current is EMF and intensity of current; applied to the coil of wire Unit is Watt (W) wound onto a soft iron bar, the - 1 Watt would indicate that an iron bar will be magnetized EMF of 1 volt moves 1 coulomb until the current is switch off of electrons (6.26 × 1018 ) in 1 Electromagnetic Induction sec. - electricity is produced from o P = EMF x I Magnetism - Result of interaction between a conductor and magnetic lines of force; EMF is produced by the magnetic lines of force - Factors of electromagnetic Current Flow induction: Conventional Current Flow - Magnetic lines of force is o Flows from positive to negative providing the electromotive Electron Flow force (No potential difference o Flows from negative to passive here) o Conductor There is the flow of the current o Magnetic lines of force o Relative movement of Magnetic Effect of an Electric Current conductor o Magnetic lines of force Ammeter – measures the ampere or the intensity/magnitude of the current When a magnet is moved into the coil, the magnetic lines of force cut across the conducting wire of the coil and cause movement of electrons in the coil, these electrons repel adjacent electrons and so on so that current is set up in the circuit - Also known as Electromagnetic Effect It also shows in electromagnetic induction that the magnet produces current  Death The current produced by electromagnetic induction is greater when the: Note: Always be careful when applying electrical magnet or coil moves faster, current modality the coil has more turns, or the magnet is stronger. If the magnet or coil is moved back and forth repeatedly, alternating current is produced Electric generators and electric transformers use electromagnetic induction to generate electricity or change the voltage of electric current THERAPEUTIC EFFECTS OF ELECTRICAL CURRENT : ▪ Facilitation of muscle contraction ▪ The current can stimulate the muscle to contract ▪ Enhance functional mobility ▪ Since it produces muscle contraction, then the patient can move that certain part ▪ Pain relief ▪ Resolve edema ▪ There is more muscle contraction, more mobility, therefore it can facilitate movement of fluid back to circulation ▪ Transport of medications ▪ Also found in Ultrasound through (Phonophoresis) ▪ Here electrical current can transport medication through (Iontophoresis) ▪ Wound healing ▪ Very rare to encounter in a rehab setting ADVERSE EFFECTS OF ELECTRICAL CURRENT Burns Encountered when exposed to high intensity current Chemical reactions Can be experienced after applying the modality Electrical Shock Earth Shock Electrotherapy field/magnetic lines of force which is induced Lesson 2: Electrical Components into the secondary coil, it then moves the Shean Emmanuel Porcia electrons so that there would be current flowing on the secondary coil Transformers The induced EMF in the secondary coil would - An electrical device that alters the depend on the number of turns of wire relative to voltage or to render the current earth the primary coil (greater turns= greater free EMF/Voltage) Question: What is current earth free? Classification of transformers Ans: The current will not go towards the ground(earth). It will not go towards the ground 1. Even-ratio transformer since the secondary coil produces the - Primary and Secondary turns are equal output/current and it doesn’t have any - Since equal there is no alteration of the connection to the ground voltage (note: the primary coil is the only one with a - It renders the current earth free connection to the ground/Earth) 2. Stepped down transformer - Fewer secondary coil turns to reduce the - Transformers consist of: voltage. It has more primary coils than o Two coils of insulated wire secondary (lesser voltage since lesser wound onto a laminated soft number or turns in the secondary) iron frame ▪ It may be wound on opposite sides or on top of one another Figure 2. Step down transformer Example for Step Down Transformer Primary coil = 300 turns; secondary coil = 150 turns Figure 1. A Transformer Voltage = 400 volts ; voltage =200 colts Ratio is: 2/1 Figure 1 shows a soft iron frame, having a 3. Stepped up transformer primary coil (left side) and a secondary coil - More secondary coil turns to (right side) INCREASE the voltage - A transformer works on the principles of electromagnetic induction o There is no connection between the primary and secondary coils Question: How does the current pass when both coils have no connection? Ans: Once current passes through the primary Figure 3. Step-Up Transformer coil it produces a certain magnetic Example for Step Up - It is the weakest point in a circuit Primary coil = 60 turns; secondary coil = 120 - Made up of a low melting point material turns (such as wire) Voltage = 100 volts ; voltage = 200 volts o If the current passing exceeds a Ratio is: ½ certain value, the heat generated melts the wire and breaks the Kinds of transformers circuit and preventing further 1. Static Transformer current flow and preventing - It is the output of the voltage (no damage to other wires or changes in the output) equipment’s 2. Variable Transformer - Connected to live wire (for this reason) - The primary coil has a number of - It bears the limit of the maximum tappings intensity of current (ampere) that it - There is a knob to turn, and by turning would allow to flow through it, you can change the number of coils in - e.g. cartridge type the primary coil o If it decreases the number of coils = produces a step-up transformer o If it increases the number of coils = it can produce a step- down transformer Figure 4. Fuse - Voltage output can vary but it is fixed 3. Autotransformer Circuit Breaker - Consist of a single coil of wire with four - It has the same function as the fuse contact points coming from it when there is a over intensity of the - Automatically changes the voltage current, it cuts off the circuit. output - It is an automatically-operated electrical - Primary coil is steady then the switch designed to protect an electrical secondary coil is the one changing thus circuit from damage caused by overload - Voltage output varies (if unsa needed na or short circuit. output, mao sd ang iya e produce) - Function is to: o Interrupt the continuity of the - Ex. Needed voltage output (Stepdown) circuit and discontinue electrical the contact flow Fuse - Compared to fuse, once it is cut or stops the flow of current, it can be reset (either - A safety device built around a manually or automatically) conductive strip, designed to melt and - Made up of varying sizes that protect an separate in the event of excessive individual household appliance up to current flow in the circuit large switchgear designed to protect - Connected in series with the high voltage circuits feeding an entire components to be protected from city overcurrent - When the fuse blows it will open the entire circuit and stops the current through the component(S)  connected to the ground, rendering the voltage to be 0V ▪ Smaller terminal is the hot line and it supplies the voltage required to produce the current Figure 5. Circuit Breaker Power Plug Figure 7. Two pronged outlet - part of the machine where it is attached o When a device is plugged, the to the outlet for the source of power electricity flow from the hotline supply towards the circuit/machine and - Two types of Plugs it ends in the neutral, which it Two Pin Plug Three Pin Plug disperses the energy into the Connected to Live and Connected to Live and ground. Neutral Wire Neutral wire and to the Three Pronged Outlet Ground Wire Much safer type of plug Figure 8. Three Pronged Outlet Fig 6. Power Plug o It has 3 terminals ▪ Neutral Terminal Electrical Outlet (Electrical Socket) (same with 2 pronged) - Allows electrical equipment to connect ▪ Hot Terminal (same to the electrical grid with two pronged) - The electrical grid provides alternating ▪ Grounding Terminal current to the outlet is connected to a ground - The two sides represent part of the wire; important to “loop of wire” and when an electrical devices with a metal device is plugged in, it completes the casing or metal cased loop, allowing electricity to flow power supply. through the device so that it can If there is presence of current in the casing, it function. can cause shock in the patient which is why the Types of Electrical Outlet grounding wire is directly connected to the casing of the device and will neutralize the risk Two Pronged Outlet of shock by diverting current to the ground, o Has two terminals which will trip the circuit breaker, and stop the ▪ Larger terminal is the current flow to the device neutral line and is Switches Types of Current - A device that open and closes the circuit Types of AC DC o Open circuit – it turns off the current flow of the current Flow of To and fro* Unidirectional o Closed Circuit – turns on the current movements flow of the current of electrons - Made up of two metal blades which fits or Periodic to the metal socket reverses Polarity at Continual Same all o if the metal base fits the metal ends of Change throughout socket it closes the circuit circuit +→ −→ (+ → +) o If the switch is on, the blades +… or(− → −) are gripped in the socket and the Examples Current in Battery circuit is complete electrical o If the switch is off, a spring supply ** sudden separates the socket and *to and fro/back and forth blades ▪ If it is separated slowly, ** Preferred since arching of the current Produces greater voltage might occur and intense The use of static transformer allows long heat would gradually distance transmission *Rectification – conversion of alternating burn away metal current to direct current contacts Electrical Wiring Types of switches 1. Push Button – push to turn on and or off Live Neutral Earth/Ground 2. Slide – sliding turns on and or off Wire (L) Wire Wire (E) 3. Rocker – commonly found in modalities (N) or for lights (0 is off, vertical line(-) is Carries the back to Used for on) current machine source protection 4. Rotary – rotating it turns on the device to *explained 5. Toggle – somewhat same with the below rocker but mura shag little joystick Wire Brown Blue Green/Yellow Color green *in cases when a live wire makes a contact with (#1) (#2) metal casing of an appliance. When this (#3) happens, the current will pass to the earth instead of human body GO BACK TO SLIDE 14 Short Circuit (4) (#5) - Abbreviated to short or s/c - An electrical circuit that allows a current to travel along an unintended path - Normal pathway  o Live wire → outlet → machine - A painful stimulation of the sensory → going back to neutral wire nerve caused by a sudden flow*, - Short circuit pathway cessation or variation in the current o Electricity strays outside of the passing through the body normal pathway of an electrical *shock only happens when this is present, it circuit does not happen when there is a gradual flow o Happens when the electrical of current flow completes its circuit via a shorter distance - Severity of Shock: o Greater intensity of current = more severe shock o Lower resistance of the skin(wet/damp) = the greater the intensity of current passing through o Passing through delicate parts of the body (head, neck, heart, whole body) = more severe shock o If the source is AC* = Provides Figure 9. Short Circuit pathway a stronger sensory stimulation Causes: o that produces tetanic muscular o Faulty circuit wire insulation contraction which make the ▪ In a wire, if there is a victim impossible to let go of tear in the wire and the the conductor two wires touches, it can cause a short circuit *intensity continually changes o Loose wire connection o Faulty appliance wiring Effects of Shock ▪ Instead of going Type Minor Moderate Major/Ex towards the neutral, the of Shock Shock treme current goes to the Shock Shock casing and further goes What Frightened Fall in BP Stop of through the ground a and respiration, cardiac Electrical Current Flow perso Distressed arrest*, n cyanosis, 1. Main Power Supply → 2. Electric Meter feels absence of → 3. Fuse/Circuit Breaker → 4. pulse, Switches/Outlets → 5.Lights/Electrical dilated pupils Modalities Consc Does not Sometimes Main Power Supply(VECO/electric companies) iousn lose loses supplies electricity, it would then flow to the ess electric meter(seen from posts in veco), it would *due to ventricular fibrillation from electrical continue to flow to the fuse/circuit breaker, then stimulation of the heart to switches(lights) or outlets(equipment/machines), and lastly to the equipment needed. Shock Causes of Shock All apparatus should be checked and maintained regularly by a competent Type of Electrical Earth Shock electrician Shock Shock Causes Sudden (+) in the Due to current connection of Precautions of Earth Shock encountered live during electrical wire/equipment ❖ Apparatus should be grounded wherein treatment and earth a ground wire is attached from the Examples when the intensity a person who apparatus to a conducting pipe which is setting is turn on touched the attached to the ground or using a three suddenly or casing of the pin plug or using a static transformer abruptly apparatus which increasing the is not grounded; ❖ Pipes should be out of reach of the intensity , patient a person who is apparatus and the patient touches an receiving ❖ Floor should be of insulating material exposed part of treatment with an and kept dry, if floor is not of insulating the circuit or apparatus that is electrodes, one of not grounded and material, a non-conducting mat should the electrode touched a water be placed under the patient’s foot suddenly fell off pipe ❖ Patient should not be allowed to touch Difference Feels pain Current from the apparatus sensation no modality to passage of the person then to * Current obtained from batteries is always earth current towards the ground the Earth/ground (current passes free so no earth shock will be encountered from to the ground) the battery supplied machine but can encounter *machine not grounded and naka shock sha, electrical shock possible both electric/earthshock Treatment of Shock *if grounded ang machine, three pin plug gi use and naka shock, electrical shock sha o Disconnect the victim from the source of supply by switching off the current or if * Electric shock may be caused if the recipient without any switch, victim should be touches a grounded object (a water pipe, removed using a thick layer of insulating radiator, or electric circuit) while being material stimulated. This is especially serious if a large o Minor shock area is subjected to the shock. Electric shock – let the victim reassured and allowed to rest may also occur if the electrical stimulator suffers - water maybe given but not hot water transformer breakdown (which is unlikely with because it can cause vasodilatation and sweating modern units). If this happens the high‐ which can further cause fall in blood tension, low frequency current may jump to the pressure recipient and produce an electrical burn as well o Major shock as a shock. (Internet) - victim is laid flat, respiratory passages should be cleared, tight clothing is loosened and Precautions of Electric Shock plenty of air to be allowed All apparatus should be checked and - undue warmth should be avoided which tested before used can cause further fall in blood pressure due to Intensity control should be checked to vasodilatation and sweating, warmth can ensure that they are at zero before also increase metabolism which increases switching on the machine demand of oxygen - if victim is unconscious, then perform Gradually increase current intensity with cardio-pulmonary resuscitation (CPR) and call care for medical Patient should never be allowed to touch assistance any parts of the electrical equipment LESSON 3 Current Waveforms LOW FREQUENCY CURRENTS Shean Emmanuel Porcia Visual representation of currents Low Frequency Currents Types: Electrons flows periodically with a 1. Monophasic frequency varying from 1Hz- 2,000 Hz Mono = 1, Phasic = phase =one o Pps = pulse per second phase Stimulate both sensory and motor nerves Waveform in either upward or and muscles downward deflection from the Skin Impedance is inversely baseline proportional to the frequency resulting Eg. Direct current to a greater skin resistance 2. Biphasic 1 𝑍 = 2 𝐹𝐶 (Z=Skin Impedance; Bi= 2; 2 phases F= Frequency; C = Capacity of the skin) One half of the cycle is above o Greater skin the baseline while the second impedance/resistance = harder half is below the baseline time stimulating the structures One complete cycle (2 phases) = under the skin (Increase single pulse intensity* to overcome the skin Eg. Alternating current impedance) 3. Polyphasic A modified biphasic current *Problem increasing intensity = chances of Produces 3 or more phases in a electrical burns, and discomfort of the patient single pulse Types of Current 4. Symmetrical Pulses have same form or shape Alternating Current 5. Asymmerical o Current periodically changes in Pulses have different shapes or a rhythmic manner and at a form specific frequency o Balanced – same size o Total number of electrons o Unbalanced – Different moving in one direction is equal size to that moving of the opposite direction Baseline o No net ion transfer/movement because of the to and fro Positive/ above movement Baseline o Polarity of charge of electron from time to time Negative/below Direct Current Baseline o Unidirectional movement of electrons o Net Ion transfer Current o Polarity or charge of electrodes Modulation are consant Continuous Mode o Uninterrupted flow of current  Interrupted mode o intermittent cessation of Interrupted Direct Current current flow Surge mode ** Types Faradic Current/ Galvanic Current/ o Gradual increase or SIDC LIDC/LDMPC decrease in the current Current Surged pulsed intensity over a finite modulation current period of time Pulse 0.02-1 ms 10-2000 ms o Consist of several Duration* pulses surged Frequency 50-100Hz 5-10 Hz rectangular, surged Uses Innervated Denervated triangular, and saw Muscles only* Muscles** and also innervated tooth muscle Ramped mode ** *If pulse duration is in between 1 -10 ms (it is o Gradual increase of classified as SIDC) current intensity, maintained at a level **Denervated muscles can’t respond to (plateaus) then starts to SHORT PULSE DURATION but responds to decrease intensity. higher intensity (more risk of electrical burn) *difference for Surge and Ramped, Surge ***Denervated muscles can respond to doesn’t plateaus LONGER PULSE DURATION *uses for surge and ramped, activated when the Direct current produces more chemical reaction muscle cannot relax. (Intensity (+) → muscle because steady ra ang polarity contracts → intensity (-) → muscle relaxes) Types of Machine/Modalities ** produce tetanic contraction (functional motion) Types of Constant Current Constant Voltage Machine Kinds of Currents How is it Therapist Therapist manipulated manipulate the manipulate the Kinds of Current Sinusoidal Faradism or current intensity voltage output Current Faradic (remain constant) (remain constant) Current Used in Stabile Technique* Type of current Even Uneven Risk of Reduces the risk of Risk of electrical alternating alternating electrical electrical burns burns since current current burns because intensity is current intensity manipulated can be varied Surged/Unsurged Both Surged How to Output shows Output shows Frequency 50 Hz 50Hz determine current is in current is in Volts Pulse Duration 10 ms 1 ms what type Amperes Graph Sine wave *Electrode is held in place Current Biphasic Waveform Muscle Nerve Physiology Resting membrane potential – relaxed state of a structure o Nerve = 70 mV o Muscle = 90 mV The cell membrane is more o Positive charged – outside* o Negatively Charged – Inside* *creates a potential difference Action Potential 1. Stimulus that causes the cell membrane to become more Neuromuscular Junction permeable to sodium Terminal end of the nerve (axonal When a stimulus is applied, it triggers the terminal end of the nerve) sodium channel to open, then sodium ions go into the cell, once inside it becomes more Depolarization starts at the proximal terminal end positive (Negative=outside, Positive=Inside) of the nerve (dendrites) → axons → terminal end of axon → terminal end of the nerve. When it 2. (Na*) ions distorts the resting reaches at the terminal end of the nerve, there membrane potential which would be an influx of calcium which triggers the generates the AP release of acetylcholine towards the membrane of (depolarization) the muscle, which then depolarizes the muscle Repolarization membrane that causes an influx of sodium which 1. Process by which potassium changes the inside of the muscle to positively channels fully opens when the charge. Once the muscle depolarizes, the sodium channels start to close. sarcoplasmic reticulum releases the calcium then Potassium rushes out of the cell it would bind with troponin C, which making the inside of the cell reconfigurates the troponin-tropomyosin negatively charge (absolute complex, which exposes the binding sites of the refractory period)* myosin with the actin which binds the myosin to actin, the myosin then now pulls the actin to the *when stimulus is applied (electric current etc) it center causing muscle contraction. would not respond since it is still in repolarization phase Propagation of Action Potential Hyperpolarization Orthodromic Antidromic 1. The potassium channels remain Conduction Conduction open long enough to repolarize Propagation Normal Opposite to the the membrane (relative of AP Direction normal direction refractory period)* Example Motor – Prox. to Evoked electrical Dist. stimulation *Hard to stimulate, but the structure can be Sensory – Dist. stimulated with high intensity. (risk for burns) To Prox. Electrical Excitability if during relative refractory period, the structures can be stimulated but with a Nerve and muscle can respond to higher intensity electrical stimulus Law of Dubois Reymond – states that in Stimulating nerve and muscle with order to electrically stimulate a nerve, electrical current can depolarize nerve there must be a sudden variation in and muscle creating AP current flow Electrical excitability of the nerve and muscle depends on: Polarity 1) Intensity of the current Cathode Anode The greater intensity = more muscle and Charge Negative Positive Electrode nerve stimulation (high intensity = risk of electrode electrical burns) Universal Black Red *should be the lowest intensity that elicit Color reaction Active Inactive/Indifferent/ Electrode dispersive 2) Duration of the current flow electrode* Less current needed if longer duration Current Less because More current flow need to of the More current if duration is short produce explanation reaction below this Nerve can respond to both short and long or duration response Muscle can respond to long duration* If nerve The surface It can be stimulated *it is not sensitive to electrical current, it takes fiber and membrane at from the farther muscle is the cathode site*** longer to respond stimulated becomes more 3) And speed at which peak intensity is negative and reached nearer to the anode, more Nerve and muscles adapts* to the current positive.** if the speed at which the peak intensity is proximal Distal reached is slow or gradual. To avoid this, *it doesn’t mean there is no charge or current speed of it should be abrupt. (there is still a charge present) mao rani ila gi use o Nerve = High accommodation o Muscle = Low/none **During resting membrane potential, the charge accommodation at all outside of the cell is positive and inside negative, placing an cathode there, the positive charges can *they cannot respond to that stimulus because attract easily to the cathode, causing the resting they adapted (Accomodation – ability of the membrane potential to be distorted, triggering the structure to adapt to slowly increasing opening of the channel for sodium ions causing intensity) depolarization, which causes AP. The side nearer to the cathode reduces the if the current stimulation falls within the potential difference more rapidly causes absolute refractory period, then the depolarization and initiate a nerve impulse and structures can’t be stimulated muscle contraction *** If anode, since positive and positive and the Less sensory stimulation because introduction of current, di sha ma attract and gradual rise of current distort, to distort the resting membrane potential, Applied to denervated muscles since higher intensity is needed muscles cant accommodate (Triangular, Sawtooth, and TERMS Trapezoidal) Neuromuscular Electrical Stimulation If innervated, structure would need (NMES) – stimulating the nerve and greater intensity because of muscle(innervated muscles) using accommodation. electricity or electrical currents as Pulse Duration – duration of the current that stimulation; device is known as stimulate the nerve or muscle neuromuscular electrical stimulator Electrical Muscle Stimulation (EMS) – Short pulse Duration – nerves respond stimulating denervated muscles using (0.02 – 1ms) electricity or electrical currents as Long pulse Duration – both nerves and stimulation; device is known as electrical muscle (10 ms and longer); produces muscle stimulator uncomfort Functional Electrical Stimulation (FES) - Pulse Interval – phase where no current being enable motor function by replacing, or produced assisting, a patient’s voluntary ability to - Structures not stimulated execute or control the impaired - Formula: atleast 2-3 times the pulse functions; utilizes neuromuscular duration to allow repolarization electrical stimulators (more tetanic o Eg. 20 ms Pulse direction contraction) ▪ 20 x 2 = 40 ms Parameters - Longer pulse interval= muscle twitch contraction Pulse Going Going Plateaus - Shorter pulse interval = tetanic muscle Waveform Up Down contraction Rectangular* AbruptAbrupt Yes Triangular Gradual Gradual No Amplitude or Intensity – magnitude of the current Saw-tooth Gradual Abrupt No or voltage Trapezoidal Gradual Gradual Yes /Abrupt - Adjusted by the therapist *More sensory stimulation; Can stimulate o Constant current machine, denervated muscle adjusted is the intensity of the current If innervated don’t use Triangular, Saw tooth, and o Constant voltage, adjusted is the trapezoidal since the muscle can accommodate. It voltage can still stimulate innervated muscle but with - Higher intensity = more discomfort & higher intensity more structures stimulated and risk of burns Exponential Progressive Current (Waveforms) Reach their peak intensity gradually or slowly (all except rectangular waveform) Types of Muscle contraction stimulation can be applied to train the muscle of its new action Muscle Twitch Tetanic Improve venous and lymphatic drainage Contraction – as there is muscle contraction, pumping Type of Short Jerky No muscle relaxation motion More ROM action would be expected that can More functional improve the venous and lymphatic Elicited Long pulse Shorter pulse interval drainage interval Prevention and loosening of adhesions – letting the muscle contract can move the joint, moving the joint can prevent or Motor Point loosen adhesion - Point at which the main nerve enters the Retard atrophy – since there is muscle muscle contraction, it can help in slowing down - Region of the muscle where a great the atrophic condition of the muscle density of terminal motor end plates is INDICATIONS: found near the surface - Frequently located at the junction of the Denervated muscles secondary to upper and middle one third of the muscle peripheral nerve injury – muscle re- belly education, retard atrophy Paralyzed innervated muscles due to Significance: stimulate only specific muscle, then upper motor neuron lesion – muscle re- there is the presence of the nerve, it helps education, retard atrophy determine the placement of the electrical pads Slight Edema – as the muscle contracts, it can cause pumping action that pushes fluids back to the circulation Therapeutic Effects o Severe edema = skin stretched = Facilitation of muscle contraction – when less protection of the structures patient is unable to produce a muscle causing burns easily contraction or finds difficulty in doing so, Hypertonic muscles – stimulating the electrical stimulation maybe of use in muscles to inhibit by itself assisting voluntary contraction; patient CONTRAINDICATIONS can voluntarily contract the muscle simultaneous with the electrical Fractures – especially nonunion; if stimulator muscle contracts, it can further displace Re-education of muscle action – inability the fractured bone to contract a muscle voluntarily can Areas of active bleeding – further result in prolonged disuse, applying bleeding can happen electrical stimulation can produce Malignancies – metastasize contraction that help to restore the sense Thrombophlebitis – can cause embolus to of movement; patient is advised to dislodge actively contract the muscle (even just to Superficial metal implants – current can attempt ) at the same time with the concentrate on the metal surface and can electrical stimulation damage the structures surrounding it Training a new muscle action – after Anterior neck – can stimulate delicate tendon transplantation or other structures that causes adverse effects reconstruction operation, electrical  such as vagus nerve that can affect the being stimulated; usually utilized to rhythmic beat of the heart stimulate specific muscle Excessive edema -requires greater o Usually the cathode electrode is intensity to stimulate the structures as used the structures are more found deeper and o Applied to smaller muscles using greater intensity can cause Bipolar technique – both electrodes are pain and risk of encountering electrical placed on the same structure burns o usually utilized for gross muscle Scar tissue – large amount of scar tissue contraction will have the current a hard time to o can be applied to large muscle penetrate causing to increase the intensity Labile technique – moving one electrode which has a greater risk of encountering from one site to the other site electrical burns Stabile technique – electrodes are not Skin lesions – any large cuts and moved; electrodes are fixed abrasions that cannot be insulated with vaseline will offer less resistance to the current and the possibility of encountering electrical burns Lack of pain sensation – patient cannot warn the therapist if too much current is encountered thus possibility of encountering overdosage that result in electrical burns Cardiac pacemaker – device maybe affected with the current that passes through it Unreliable patient- unable to understand instructions that can contribute to risk of encountering overdosage Infection – infection might can spread to the adjacent areas Cold muscle – cold can reduce conductivity to the current How often the modality is applied Frequency of application – can be everyday; twice a day, thrice a day Duration – 5 – 10 minutes; 90 – 200 (Muscle twitch contraction) contractions with rest after 30 contractions Intensity – ideally enough that there would be a visible muscle contraction Techniques of electrode applications: Unipolar / monopolar technique – only one electrode is placed on the structure  Reaction of structures to electrical stimulus Lesson 4 can be affected with the following: Electrodiagnosis Skin and subcutaneous tissue resistance Shean Emmanuel Porcia to the current Uses electrical stimulators which produces ○ Greater Resistance = Higher current to diagnose, assess or evaluate certain Intensity to overcome the resistance condition Edema It is the study of electrical activity of motor ○ Structure stimulated are deeper units when stimulated by electrical pulses Consider the normal and abnormal behavior located, requiring higher intensity of the response of motor unit when stimulated to reach the structures Results can be used for diagnosis and inflammation and pain prognosis in disorders of neuromuscular ○ When pt is feeling discomfort, complex giving electrical stimulus can add Motor Unit more discomfort which can affect It is the functional unit centrally controlled the result of electrodiagnosis muscle function and consists of the ff: Temperature anterior horn cell ○ It increases the sensitivity of neuron and structures resulting in lesser muscle fibers innervated by the neuron intensity. cold decreases the NERVE FIBERS VS. MUSCLE FIBERS sensitivity of structures resulting in the need for higher intensity. Nerve fibers Muscle fibers amount of subcutaneous tissue Response to long and short pulse more to long pulse ○ Thicker Subcutaneous tissue = duration duration structure become more deeply situated = higher intensity needed Long Pulse Duration = Less Intensity Humidity Short Pulse Duration = ○ Hot = Decreases Intensity (allows Higher Intensity current to flow) accommodation present* little or none Electrode at the structure property ○ Cathode = Less intensity to *Can be overcome by increasing the intensity stimulate the structure and using abrupt change of intensity Location of muscles (rectangular) ○ Superficial = Easily Stimulated Reaction of Degeneration Size of muscles Muscles are deprived of their nerve supply ○ Larger = Higher Intensity needed or denervation ○ Smaller = Lesser Intensity needed won't respond to short pulse duration (Only Pressure application from the electrodes muscle will respond to the pulse) ○ Greater pressure = greater current two types density, therefore lesser intensity 1. Partial reaction of degeneration needed to stimulate the structure Decrease response to short pulse duration ○ Near distance from structure = less (degeneration of the nerve on the structure) intensity needed 2. Complete reaction of degeneration Tension of the muscle No more response to short pulse duration ○ Greater tension = lesser tendency to (no more nerve, only muscle left) contract resulting to the need of higher intensity  Electrodiagnostic Methods More twitch Contraction ED Rheobase Chronaxie Accommodatio Strength Duration Pulse Ratio Nerve Methods n ratio/quotient Curve Excitability Test Descripti Least Duration in Ratio between -A curve obtained in the -Ratio of the Determines the on intensity of milliseconds impulse graph by joining points intensity of the state of the current necessary to threshold of that represent the current needed to excitability of required to produce (exponential threshold values along the produce a the nerve trunk produce minimal progressive ordinate(y-axis) for muscle which causes minimal perceptible or current***) to various durations of contraction with several muscles perceptible palpable or the impulse stimulus at the 1ms to that to contract or palpable visible threshold of abscissa(x-axis) required to or visible contraction rectangular - minimal palpable or produce muscle Minimal contraction with a pulse using the perceptible or visible contraction with perceptible/palpa using a stimulus that same pulse contractions should be 100 ms ble or visible pulse of is twice the duration elicited contraction is infinite rheobase needed t duration Parameter -Pulse Same As Exponential -Pulses (choose from 6- Uses Short Settings Waveform: Rheobase progressive 10) Pulse duration Rectangular But intensity current impulse -Pulse Duration (0.02- (0.1 ms or 1ms) (1) is 2x the threshold 1,00 ms) -Pulse rheobase -Long Pulse Duration Rectangular Duration: rectangular (100ms) Pulse waveform Long (100 - current impulse -Done 10-14 days after 300ms)* threshold the onset of lesions Pulse interval is the highest PD chosenx2 Normal 2-18mA; 5- Less than 1ms. Normal ratio: Utilization Time(*****) Innervated: less Compare the values 35 V** ( 0.05- 0.5 ms) 3 to 6 than 2.2:1 ex values of one -Innervated: The graph 1ms of pulse side to the Denervated: is more at lower level at duration = 10mA opposite side and Below 3 the curve shifts to the left for 100 ms =5 a difference of mA 3mA or 8 volts No -Denervated: That graph (10mA:5mA= 2) or more will accommodation: is steeper and curve shift indicate 1 and below to the right Partially denervation (absence of Innervated/Den nerve) -Partially ervated: greater Ex. L side Innervated/Denervated: than 2.5:1 ex. 10mA; R side 14 Presence of kink; R (15mA:5mA=3) mA (Difference portion are denervated 4mA = component and L side are denervation) innervated component Complete Denervated: no Denervated:R side kay needs greater response to 1ms intensity to stimulate *Pulse Interval (2-3 x of the pulse duration), intensity would be lesser ** intact nerve/muscle ***Triangular, Sawtooth, Trapezoidal (*****)(point at which the curve begins to flatten horizontally) can be determined, which signify the probable pulse duration which will be suitable for stimulation if the structure is to be treated  (1) We don’t know if innervated or denervated ang structure; least intensity dapat; if innervated, structure would not accommodate; if denervated, di sd mo accommodate. If exponential, the structure would accommodate, to overcome, increasing intensity. Different Sites of the nerve trunk Nerve Location of Electrode Action Facial nerve Anterior to mastoid process contraction of facial muscle Erb's point lower inner angle of the contraction of deltoids, biceps supraclavicular fossa brachii,brachialis, brachioradialis Ulnar Nerve Above medial Contraction of wrist epicondyle flexors, Ulnar Dev., Finger Flex ❖ Above Wrist near Ulnar ❖ Wrist Extensors and Border Finger Extensors. Radial Nerve Halfway of the arm posteriorly Wrist extensors and finger extensors Tibial Nerve Above the center of popliteal plantar flexor of ankle and toes fossa Deep Peroneal Nerve behind the head of fibula ankle dorsiflexors Superficial Peroneal Nerve 1 cm below the deep peroneal Ankle evertors nerve LESSON6: DIADYNAMIC CURRENTS Contraindications AND HIGH VOLTAGE GALVANIC Same as LFC devices STIMULATION ➔ Skin Lesions (Dermatitis, Eczema, Shean Emmanuel Porcia Psoriasis, Acne) DIADYNAMIC CURRENTS ◆ Can further spread condition - A variation of sinusoidal current* ➔ Open lesions/wounds being rectified** ◆ Greater risks for burns *Sinusoidal Current - Even alternating currents **rectification/rectified - conversion of AC to DC ➔ Infection - Utilizes Low Frequency Currents ◆ Activate the microorganism (freq. 50 Hz c 10 ms each pulse) or makes it hyperactive - For Pain Relief not on muscle ➔ Impaired Sensation stimulation. ◆ Cannot feel and warn the - It can stimulate both motor nerves therapist if the intensity is too and muscles high ➔ Thrombosis Therapeutic Effects ◆ Dislodge the thrombus and 1. Masking effect or counter-irritation might form an embolus effect ➔ Tumor/Cancer a. pt feels more on tingling ◆ Can metastasize to other sensation which masks the areas pain felt by the pt. ➔ Cardiac Pacemaker 2. Vasomotor Effect ◆ Can interrupt the function of a. Produce vasodilatation (+ the device circulation) and hyperemia ➔ Unreliable patient (reddening) because of the ◆ Can’t rely on them when we release of histamine try to ask them if intensity is 3. Muscle Stimulation too high and risks for burns a. Currents can stimulate the ➔ Superficial metal implants muscle ◆ Metals are good conductors Indications of currents and risk the ➔ Sprain/Strain surrounding structures to be ➔ Contusion ✅ damaged/injured ➔ Epicondylitis ✅ ➔ Scar tissues ➔ Arthritis ◆ Greater resistance to current ➔ Neuroglia flow → + currents which can ➔ Neuritis (inflammation of nerve) ✅ cause electrical burns ➔ Pregnant uterus ➔ Radiculopathies ◆ Direct application can have ➔ Myalgia an effect on the fetus or - Presence of Pain; Rationale: Mask the pain womb of mother ✅- Presence of Pain and Vasodilatation; Rationale: Pain- Masking Effect, Vasodilatation - hasten healing ◆ Further away allowed ra process due to increase circulation  Types of Diadynamics Type DF (fixed MF (fixed LP (long CP(short RS (Syncopal diphase/diphase monophase/mono periods/longues periods/courtes Rhythm) fixe) phase fixe) periodes) periodes) Description Full wave Half wave Unequal DF and Equal MF and DF 1s MF then 1s rectified AC rectified AC MF phases; 10s phases (1s each) rest MF phase then (ONLY 1 c 5s DF phase REST!!) Order from 1 4 2 3 Mildest to Strongest Strongest to 4 1 3 2 Mildest Indications Initial treatment Treatment of Traumatic Pain Long lasting For muscle before the pain without analgesic effect stimulation application of muscle spasm (pain, circulatory other currents (pt problem) adapts to the feeling or intensity) Treatment for circulatory disorder Sensation Prickling/Tingling Prickling/Tingling Prickling/Tingling Prickling/Tingling Prickling/Tingling Muscle Higher Intensity Lower intensity c sufficient c sufficient Present contraction than DF intensity intensity Avoid producing muscle contraction for DF, MF, LP, and CP(highlighted green) since there is NO RESTING PERIOD unless you want to fatigue the muscle Intensity - depends on pt sensation; Duration - 10-12 mins; Frequency - Can be given daily No parameters kay it is already set sa machine Methods of Application Method Description Pain spot Application Uses 2 electrodes applied at the sides of the pain spot or either one is place directly on it Nerve Trunk Application Placed at the course of the peripheral nerve Paravertebral Application Applied on both sides of the spine or at one side Vasotrophic Application Along the vascular paths affecteed Myo-energetic Application Applied at the muscle Transregional Application Applied on the opposite surface area HIGH VOLTAGE GALVANIC Indications STIMULATION (HVGS) OR ➔ Pain Relief HIGH VOLT PULSED CURRENT (HVPC) ◆ Masking/counter irritation ◆ Release of endogenous - Produces a high voltage og(?) gates current(intensity) with high peak ➔ + Circulation intensity ◆ Vasodilatation - Because of short pulse duration it ➔ Healing of Ulcers has a low average current ◆ Some cells will be attracted - high peak intensity produced can to the polarity of the reach a maximum of 300-400 mA electrode (electrical - pulse duration ranging between 50 – stimulation, LFC part 2) 100 microseconds so that it is more ➔ Decrease Muscle Spasm comfortable because of short ◆ Stimulate the muscle until the duration* muscle relaxes (autogenic *pulse interval might be programmed; no parameters are adjusted since it is preset inhibition) - Pulse frequency for tissue healing in the ➔ Reduction of Edema range of 60-125 ◆ Because of the pumping - will not produce muscle action of muscle contraction contraction in denervated muscle* Contraindications as the pulse duration is too short to SAME WITH LFC MODALITIES depolarize the muscle (does not stimulate) Intensity *because denervated muscles need a longer pulse Depends on tolerance or sensation of duration to produce contraction patient - Innervated muscle can be stimulated Duration - Twin pulsed ↓ 20 mins