Exam 2 Study Guide Flashcards
Pulse Period
amount of time from the start of one pulse to the start of the next pulse
Pulse Duration
contributes to the comfort of the stimulation, the amount of chemical changes that occurs in the tissues, and nerve discrimination. 50 to 100 us is typically used for sensory stim, 200 to 300 is used for motor stim
interpulse interval
time between the end of one pulse and the start of the next pulse, allows for mechanical changes in the tissues, such as when eliciting muscle contractions
Constant Current Stimulators
the advantage is to ensure a consistent physiological response during the treatment, the negative is potential pain when the voltage increases to overcome resistance.
Constant Voltage Stimulators
This unit is advantageous in preventing discomfort with changes in resistance, but quality of response can be decreased with these automatic resistance changes
What is the advantage of pulsed biphasic current? How can a physical therapist manipulate duration and frequency to treat a variety of ailments?
This is alternating current with Interrupted flow of charged particles where the current flows in a series of pulses separated by periods where no current flows. Used for pain control, tissue healing, muscle contraction and is the waveform most often used for electrical stimulation
What is interferential current? How is IFC set up differently than pulsed biphasic?
Interference of 2 medium frequency alternating currents of different frequencies, delivered on separate channels/electrodes (placement of electrodes matter)
Benefit: the different waveforms reduce impedence allowing for a deeper sensory experience, great for joint pain (“bracket the joint”)
What is modulation? Why would a therapist consider using modulation?
Irregular patterns of stimulation to minimize the accommodation effects of regular patterned stimulation. It is useful for patients who use TENS for multiple hours in the day.
Describe how iontophoresis works
Iontophoresis is the use of DC current for transdermal drug delivery for musculoskeletal inflammation. Polarity of medication is matched to the polarity of the electrode. Medication is pushed into the stratum corneum over a targeted anatomical structure (dexamethasone)
How is iontophoresis different than phonophoresis?
Phonophoresis is the use of sound energy, it also transports whole molecules into the skin while iontophoresis transports ions into the skin
Impedance
The resistance of the tissue to the passage of electrical current.
Electrical Current (negative and positive electrodes)
Negative electrode: Cathode (black cat) high electron concentration, active electrode and attracts positive ions. Alkaline reaction
Positive electrode: Anode low electron concentration, thus will attract negative ions. Acidic reaction
ONLY USE THESE TERMS WITH MONOPHASIC CURRENT
Circuit Types
Series Circuit: one pathway is available for travel (this is how current enters the body)
Parallel Circuit: two or more routes exist for the current to pass between the two terminals (this is how current moves in the body)
Human Tissue: Conductor or Non-Conductor
Skin: offers the chief resistance to current flow and is considered an insulator. The greater the impedance of the skin, the higher the voltage of the electrical current must be to stimulate the underlying nerve and muscle.
Blood (best conductor), muscle (good conductor), tendons (poor conductors), fat (poor conductor), bone (poorest conductor)
Effects of Electrical Stimulation
Electrical currents exert physiological effects by depolarizing the nerve membranes resulting in production of an action potential. Electrical currents reverse the electrical gradient of the nerve to create a depolarization.
Amplitude
Increasing amplitude provides current to deeper tissues. Lower settings = sensory stimulation, higher settings = motor level stimulation, also termed intensity. Amplitude and pulse duration have the most impact on how a patient feels and responds to electrical currents.
Pulse Duration/Width
Short duration with low intensity depolarizes sensory nerves
longer pulse durations are required to stimulate motor nerves.
very long pulse duration with high intensity is needed to stimulate denervated muscle.
interpulse interval
Increasing the pulse frequency decreases the interpulse interval and vice-versa
Pulse Frequency/Pulse Rate
E-Stim = more fatiguing, preferential to type II muscle fibers
Contributes to the type of contraction.
1-10 pps = twitch contraction
>30 pps = tetanic contraction
30-70 pps = non-fatiguing tetanic contraction
100-1000 pps = fatiguing tetanic contraction
Monophasic/Direct Current (DC)
Flow of electrons is unidirectional, polarity is constant. The placement of the cathode and anode electrodes matter, want to create chemical changes by building polarity.
Alternating Current (AC) or Pulsed Biphasic Current
The placement of the cathode and anode does not matter, bidirectional flow of electrons marked by periods of noncurrent flow. Jack of all trades, 3 types of biphasic currents: Symmetrical (most common), balanced asymmetrical or unbalance asymmetrical is not commonly used.
Strength Duration Curve
Represents the minimum combination of current strength (amplitude) and pulse duration (msec) needed to depolarize motor nerves.
A-beta nerves, motor nerves, a-delta nerves, C fiber/ dull pain nerves, denervated muscle
Lower amplitudes and shorter pulse durations (<80 us)
depolarize sensory nerves
Higher amplitude and longer pulse durations (150-300 us)
depolarize motor nerves
What is a motor point?
Area of greatest excitability on the skin surface at which a small amount of electrical current generates a strong muscle contraction.
How can you find motor points?
Locate motor points by trial and error
Innervated muscles – where motor nerve enters the muscle, over the belly.
Denervated muscles – over the muscle distally toward the insertion
Accommodation
Process by which a nerve gradually becomes less responsive to stimulation.
Electrode size has effect on current density…
Small size = high density, low current spread (better for small muscles)
Large size = less density, increased spread (better for large muscles)
Electrode placement has effect on current density
Spacing between electrodes affects the depth and course of currents, close spacing results in superficial application, far apart spacing results in deeper application, minimum 1 inch apart.
Quadrapolar Technique
Four electrodes of equal size, requires two channels or leads, currents intersect with each other, most popular use is with interferential stimulation.
Bipolar Technique
Electrodes from leads are of equal size, resulting in nearly equal current density under them, sensory and motor applications.
Monopolar Technique
Electrodes of unequal size, creating active and dispersive electrode (larger) applied to remote location. Active electrode applied to treatment area, dispersive electrode applied to remote location, iontophoresis is the primary example.
Indications for TENS
Pain relief
Indications for Monophasic
Reduce edema, wound healing, improve circulation, administer medication, stimulation of denervated muscle, fracture healing.
Indications for NMES
Reduce edema, decrease atrophy, increase strength and endurance, muscular reeducation, improve circulation.
Indications for FES
Decrease atrophy, increase endurance, muscle reeducation.
Indications for Micro current
Fracture Healing
Low-Rate TENS
low frequencies (2-10pps) and long durations combined with high intensities, produce brief sharp pain resulting in release of endogenous opioids. Recommended when a longer duration of pain control is required (hours)
High Rate TENS
Recommended when sensation, but not muscle contraction will be tolerated. Example is after a recent injury where inflammation is present or over tissues that may be damaged by muscle contraction
High Rate E-Stim pulse frequency
100-150 pps
High Rate E-Stim pulse duration
50-80 us
High Rate E-Stim amplitude
to produce tingling
High Rate E-Stim treatment time
PRN for pain control, no set time (24/7)
High Rate E-Stim possible mechanism of action
gating at the spinal cord
Low-Rate E-Stim pulse frequency
2-10 pps
Low-Rate E-Stim pulse duration
200-300 us
Low-Rate E-Stim amplitude
to visible contraction
Low-Rate E-Stim treatment time
20-30 min
Low-Rate E-Stim possible mechanism of action
endorphin release
Electrode Placement
Placement around the painful area is the most common approach. If unable to access the pain site, can apply electrodes just proximal to the painful site along the sensory nerves supplying that area
Documentation for TENS
Area of body treated
Patient positioning
Specific stimulation parameters
Electrode placement
Treatment duration
Patient response
Pre/post test or inspection
Indications for electrical currents for muscle contraction
Strengthening, decrease rate of atrophy, spasticity management, edema management, increase local blood flow, improve ROM, improve muscle endurance, muscle reeducation, improve gait, reaching, and grasping activities.
Parameters for Muscle contraction (muscle strengthening)
Pulse frequency: 35-80 pps
Pulse duration: 125-200 small mm, 200-350, large mm
Amplitude: greater than 10% MVIC injured. Greater than 50% MVIC non injured
On: Off times/ratio: 6-10 secs on, 50-120 seconds off; 1:5 ratio initially
Ramp time: at least 2 seconds
Treatment time: 10-20 min to produce 10-20 reps
Times/day: Every 2-3 hours when awake
Parameters for muscle contraction (muscle reeducation)
Pulse frequency: 35-50 pps
Pulse duration: 125-200 small mm, 200-350, large mm
Amplitude: Sufficient for functional activity
On: Off times/ratio: depends on the functional activity
Ramp time: at least 2 seconds
Treatment time: depends on the functional activity
Parameters for muscle contraction (muscle spasm reduction)
Pulse frequency: 35-50 pps
Pulse duration: 125-200 small mm, 200-350, large mm
Amplitude: to visible contraction
On: Off times/ratio: 2-5 sec on, 2-5 sec off
Ramp time: at least 1 seconds
Treatment time: 10-30 min
Times/day: Every 2-3 hours until relief
Parameters for muscle contraction (edema reduction using muscle pump)
Pulse frequency: 35-50 pps
Pulse duration: 125-200 small mm, 200-350, large mm
Amplitude: to visible contraction
On: Off times/ratio: 2-5 sec on, 2-5 sec off
Ramp time: at least 1 seconds
Treatment time: 30 min
Times/day: 2x/day
NMES
Neuromuscular electrical stimulation, use of electrical currents to increase muscle contraction in innervated muscle, works for persons with intact peripheral nervous systems
What can the PT do to minimize muscle fatigue during the application of NMES?
Vary current amplitude, modify configuration and/or electrode placement, modify muscle length, provide rest
Functional Electrical Stimulation (FES)
Use of NMES to enhance control of movement and posture (muscle reeducation), improves hand function, locomotion and respiration using transcutaneous and percutaneous ESTIM systems. Requires the lowest “dose”, focuses on functioning rather than strengthening
Atherogenic Inhibition
Reflexive inhibition/weakening of the muscles around a joint to protect it from further damage, decreased muscle activation, stability, proprioceptive control. Developed after pain, injury or dysfunction.
NMES pulse duration
125us to 350us to stimulate motor nerves, shorter durations for smaller muscles, longer durations for larger muscles. However with shorter durations, you will need higher intensities
NMES pulse frequency
35-50/80pps
Temporal Motor Recruitment
As frequency increases the muscle twitches will occur more closely together resulting in increased comfort, but with worsening fatigue
Electrical Currents for Tissue Healing and Edema Control, Iontophoresis
Chronic wounds: pressure ulcers, diabetic ulcers, venous ulcers, accelerates healing (used for stubborn healing)
Precautions for applications to wounds
Particular attention paid to wound care, cardiac disease, impaired sensation and mentation, infection control
Galvanotaxis
Movement of cells (macrophages, neutrophils) in response to electrical current. Galvanotaxis means attraction, use negative electrode if infected, positive electrode if no infection
Parameters for Iontophoresis
Direct current: continuous, monophasic, constant current
Amplitude: 0-4 mA per minute
Dosage: minimal is 40 mA-min and Maximal is 80 mA-min
Key concept:
In order for iontophoresis to work there must be enough current to overcome the resistance of the skin and electrode
Drugs delivered by iontophoresis must be…
ionized, stable, small/moderately sized and water soluble. Dexamethasone and lidocaine are only drugs recommended
Dexamethasone
negative polarity used to promote penetration of the negatively charged ion through the skin
Lidocaine
positive ion so will require the anode electrode to deliver the medication through the skin.
Traction
goal is to provide a traction force that leads to a distraction of the zygapophyseal joints
Indications for Traction
Cervical herniated nucleus pulposus
Radiculopathy
Sprain/strain
Zygapophyseal joint syndromes
Myofascial pain symptoms in the neck
Increased neck muscle spasm/guarding
MAIN USE IS FOR NECK PAIN RELIEF
Joint Mobilizations have 3 contraindications
Hypermobility, joint effusion, inflammation
Centralization
symptoms become more localized or move closer to the spine. Cervical UE diminish or return to the neck. Lumbar LE diminish or return to the back. Can make neck/back pain worse, but the key positive sign is the extremity symptoms are gone indicating the nerve root is less irritated.
Peripheralization
symptoms become more distal and extremity based, symptoms are moving away from the spine. Cervical, shoulder pain extends to the digits. Lumbar buttock pain extends to the knee. Key sign the treatment is not working and needs to be stopped.
Cervical Traction Parameters
Joint distraction: total traction force (20-29lbs), hold/relax times (15/15), total traction (20-30 mins)
Disc problems or stretch soft tissue: total traction force (11-15lbs), hold/relax (60/20), total traction time (20-30 mins)
General guide: Typically start at 8-10 lbs and increase up to 7% of the patients bodyweight
For patients with acute neck pain with radiating pain
Clinicians may provide mobilizing and stabilizing exercises, laser, and short-term use of a cervical collar
For patients with chronic neck pain with radiating pain
Clinicians should provide mechanical intermittent cervical traction, combined with other interventions such as stretching and strengthening exercise plus cervical and thoracic mobilization/manipulation
Documentation for traction
Type
Area
Patient position
Maximum force
Total treatment time
Response to treatment
With intermittent traction, also add hold time, relax time, force during the relax time
Clinical Use: Venous Stasis Ulcers
Compression can improve venous circulation, improve rate of healing of venous stasis ulcers, multilayered compression is more effective than single layer. Compression therapy is the cornerstone of venous ulcer treatment.
Short Stretch bandages
develop high working pressure (30 to 90% stretch)
Long Stretch bandages
develop high resting pressure (100-200%)(better for bedrest)
Working Pressure
“active” pressure, tissue pushing against inelastic bandage
Resting Pressure
“passive” pressure, elastic bandage is pushing on resting tissue
Clincial Use: DVT prevention
DVT increases with reduced local circulation so compression bandages can increase circulation and reduce DVT formation (sequential compression device, TED hose, put on before mobilizing patient). Effect is greatest when used in combination with other forms of DVT prophylaxis.
Clinical use: Residual limb shaping after amputation
Static and intermittent compression used
* Intermittent compression can reduce residual limb in approximately half the
time as other techniques.
* Static compression most often used
Clinical use: Control of hypertrophic scarring
Common complication of deep burns, compression of 20 to 30 mm Hg for 23 hours is recommended to reduce height, compression acts as a mold for growth of new tissue.
documentation of compression
Type of compression
Area of body where compression is applied
Patient position
Inflation and deflation times
Compression or inflation pressure
Treatment duration
Response to intervention
Advantages for diathermy
Excellent deep heater, covers LARGE areas (best depth and coverage of all the deep heaters), uniform heating, slow rate of cooling, non thermal and thermal effects are possible.
disadvantages for diathermy
Poor small area heater, large number of contraindications
Purpose of Effleurage
Relaxation, increase venous and lymphatic drainage, introduction and conclusion to other techniques
Purpose of Petrissage
Stimulate circulation, free adhesion, relaxation, “milk” the muscle of “waste products”, “wringing out the towel”
Percussion
Repeated rhythmical light striking of the skin, used for respiratory ailments to promote mobilization of secretions, simulation of muscles for activity
Vibration
Shaking of muscles for relaxation or stimulation
Trigger points
Hyperirritable foci lying within taut bands of muscle, which are painful upon compression and which consistently refer pain to a distal site or a site away from the point of origin.
Active trigger points
Tender spot, may refer pain
Local twitch response with strumming
ROM painful and restricted
Active muscle contraction may increase pain
Latent trigger points
Characteristics of active point, but pain only with palpation
Person may be unaware otherwise
Trigger point push and hold technique
Push & Hold. Use Deep Pressure on the TrP – lock into it (3-D?) and hold
Trigger point technique oscillate
Press on the TrP engaging the outer layers & oscillate for 30 sec until it releases; then move deeper and deeper
Trigger point technique cross-fiber & friction
Use deep pressure to rub either across the fiber direction of the muscle with the TrP (cross-fiber) or across the TrP to create friction (circular or moon strokes)
Trigger point techniques active contraction
Contract Relax. Test the motion first, use an isometric hold in the opposite direction (mild antagonist contraction) then move back to the test direction (agonist muscle direction)
Trigger points techniques strain-counter-strain
For active TrP’s pushing into it will cause more stretch & you find yourself fighting the tissue tension. Instead use light pressure with a 3-Plane relaxation of the tissue; Hold 90 sec causes the TrP to reset / relax; passively move them back to neutral
