Physical Agents Exam 2

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Physical Agents Exam 2
2011-03-12 18:32:29
Physical Agents Exam

Physical Agents Exam 2
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  1. magnetic field method (diathermy)
    eddy currents cause movement in tissues creating friction which increases tissue temp.
  2. is a pulsed short wave diathermy used for thermal or non thermal effects?
    usually used for non thermal

    but under certain parameters can elicit thermal effects
  3. effects of continuous short wave diathermy (thermal) (6)
    increase tissue temp


    elevation of pain threshold

    accelerate enzymatic activity

    increase soft tissue extensibility

    increase muscle contraction
  4. ultrasound and diathermy are what type of mechanism?
  5. Mild heating of diathermy facts:
    wave frequency?
    frequency of treatment?
    • usually for acute conditions
    • 2-5 mins
    • feel minimal sensation of heat
    • 27.12 mHz
    • usually daily for 1-2 weeks
  6. vigorous heating of diathermy facts:
    wave frequency?
    frequency of treatment?
    • usually used for chronic conditions
    • 20-30 mins
    • feel comfortable level of heat
    • 27.12 mHz
    • daily to 2x/wk for 1 wk-1 month
  7. Dosage scheme for diathermy

    dose 1=?
    lowest-just below the point of any sensation of heat (acute inflammatory process)
  8. dosage scheme for diathermy

    dose 2=?
    low-mild heat sensation barely felt (subacute, resolving inflammatory process)
  9. dosage scheme for diathermy

    dose 3
    medium-moderate but pleasant, heat sensation (subacute, resolving inflammatory process)
  10. dosage scheme for diathermy

    dose 4=?
    • heavy-vigorous heating that produces a well-tolerated sensation (chronic)
    • -pain threshold may be reached, output is moderately lowered to just below maximal toleration
  11. Therapeutic US frequency
    .7-3.3 MHz
  12. US uses ________ waves and diathermy uses _______waves?
    US uses acoustic

    Diathermy uses electromagnetic
  13. Do acoustic waves need a medium to be used?
  14. do electromagnetic waves use a medium?
  15. Therapeutic US and Audible frequencies( decrease or increase) in intensity when they move farther away from their source?
  16. Therapeutic US reaches how high in frequency?
    20,000 cycles per second (hz)
  17. Audible sound reaches how high in frequency?
    16-20,000 Hz (normal human hearing)
  18. US biophysical effects (6)
    increase temp of deep/superficial tissues

    increase metabolic rate

    decrease pain

    alternation of nerve conducting velocity

    increase circulation

    increase soft tissue extensibility
  19. US frequency
    1 MHz deep structures

    3 MHz superficial structures
  20. US duty cycle
    100% = continous= thermal

    20%= pulsed= nonthermal
  21. US intensity
    <.5 W/cm2 (acute)

    .5-1.2 W/cm2 (subacute)

    1.3-3.0W/cm2 (chronic)
  22. Duration of US
    normally 5-10 mins
  23. increase duration of US for:
    lower intensities

    lower frequencies

    larger than 2x ERA

    thermal effects
  24. decrease duration of US for:
    higher intensities

    higher frequencies

    area smaller than 2x ERA

    non thermal effects
  25. ERA =?
    area of the transducer from which US energy radiates

    always smaller than area of transducer head
  26. Thermal effects of US advantages (5)
    acceleration of metabolic rate

    reduction or control of pain and muscle spasms

    alteration of nerve conduction velocity

    increased circulation

    increased soft tissue extensability
  27. advantages of non-thermal effects of US (7)
    increases intracellular calcium levels

    increase skin and cell membrane permeability

    promotes normal function of a variety of cell types

    increases mast cell degranulation

    promotes macrophages

    increases nitric oxide synthesis

    stimulates proteoglycan synthesis of chondrocytes
  28. EMG biofeedback =?
    application of EMG to give a patient info-in the form of visual or auditory about muscle activity
  29. purpose of EMG biofeedback?
    increase/decrease a muscle contraction based on feedback given to a patient from a particular muscle
  30. Development of Action Potential:
    exits ____and travels to_____

    ____travels from synaptic cleft to _______ on sarcolemma

    acetylcholine _____ permeability of K/NA in postsynaptic membrane which is called ____

    endplate potential is conducting _____ from NMJ and can result in AP in ____ sarcolemma
    spinal cord travels to NMJ

    Ach travels to post synaptic receptors

    increases permeability endplate potential

    away from adjacent
  31. EMG ultimately detects:
    Depolarization of a sarcolemma
  32. small magnitude contraction for EMG
    0-10 microvolts
  33. large magnitude for EMG
    0-1000 microvolts
  34. Threshold is higher for _______

    Threshold is lower for ________
    muscle activation

    muscle inhibition
  35. motor recruitment =?
    conditions in which increasing muscle contraction is the goal
  36. motor inhibition =?
    conditions in which decreasing muscle contraction is the goal
  37. EMG and the spine is defined as....?
    identify postural dysfunction and stabilization issues that are leading contributors to pain
  38. Compensatory patterning in EMG
    prime movers are usually inhibited by pain, deconditioning, or disuse

    which = overactivity of accessory muscles= increased pain and creates maladaptive patterns
  39. stabilization =?
    muscle activation which accomodates changes in posture rapidly with proper synergistic action and at a high level of skill-thereby reducing unnecessary displacement of the COG
  40. Abnormal recruitment can result in ________and ________
    trigger points and myofasical syndrome
  41. microvolts for total body relaxation=?
    1 to 3.5 mV
  42. Dosage for total body relaxation
    30-60 mins
  43. Responses to total body relaxation
    decreases sympathetic nervous system activity
  44. Jacobsen's Technique purpose
    help person understand and recognize tension and gain more control over body, decrease pain, maximize benefit of bedrest
  45. Ideal temp for hands is _______and feet is ______
    hands: 93-95d

    feet: 90d
  46. the use of information from electrical activity of the body to determine a diagnosis in a patient with suspected neurological or neuromuscular dysfunction. Tests may include nerve conduction studies that measure peripheral motor, sensory, and mixed nerve function
  47. at the atomic level, it is the balance between protons and electrons. Like charges repel and unlike charges attract. Charge cannot be created or destroyed. Measured in Coulombs (C)
    electrical charge
  48. the unit used to express the force exerted between 2 electrical charges.
  49. Define Coulomb's Law
    larger the respective chargers or the closer the 2 charges =the larger the force between them
  50. the work that must be done to move a unit of positive charge (1 coulomb) from one point to the other point (potential energy of the charge) measured in V
    potential difference
  51. energy required to move 1 coulomb a distance of 1 meter against a force of 1 newton. represents driving force that makes charged particles move.
  52. the movement of charged particles thru a conductor in response to an applied electric field. net movement of positive charges per unit time and is measured in amperes
  53. movement of 1 coulomb of charge per second
  54. any object thru which electric charges can flow easily, determined by the ability to give up electrons from the outer orbital shell when placed in an electric field. Tissues containing Na, K and Cl- are good at these (nerves, muscles)
  55. the ease with which tissues move thru a medium and conduct electricity
  56. poor conductors of electricity (fat and skin). does not allow easy movement of charged particles in an electric field
  57. the reciprocal amount of conductance, a measure of the resistance to current flow, measured in Ohms. relative opposition of charged particles in a conductor
  58. current=voltage/resistance, therefore current increases as the voltage increases or as resistance decreases
    Ohm's law
  59. the ability to store charges of opposite signs. A capacitor consists of 2 conductors separated by an insulator. Nerve membrane is an example. measured in farads
  60. opposition to alternating currents (similar to the way resistance describes the opposition to direct currents) dependent on resistance and capacitance measured in Ohms
  61. the point where a nerve enters the muscle, and is usually near the belly of muscle. if motor point is present and responsive you can assume nerve is intact
    motor point
  62. when a nerve is damaged, thsi is the area on the muscle where you can get most of the fibers to fire with electrical stimulation. this area is usually where the most muscle fibers are arranged, close to a tendon
    area of optimal response
  63. this is how a muscle responds to a particular current, and provides info on the intergrity of alpha motor neurons. test is based on differences between reactions of innervated and denervated muscle to short and long duration electrical stimulation. it helps determine integrity of nerve muscle complex and is an indication of denervation if present.
    reaction of degeneration testing
  64. ______ RD sluggish or dimished response to alternating or direct current
  65. ______RD is no response to alternating or direct current
  66. amount of time it takes the body to respond to a stimulus that is applied at the motor point of a muscle.
    strength duration curve
  67. rheobase=?
    amount of current, at a very long pulse duration, required to produce a minimal response in a muscle (strength of a stimulus)

    normal is 2-8mA
  68. chronaxie=?
    amount of time it takes to produce minimal response at 2x rheobase.

    normal range 100 usec
  69. damage to single nerve or nerve group, and results in loss of movement, sensation, and other functions of that nerve
  70. neurological disorder that occurs when many peripheral nerves in the body malfunction simultaneously
  71. conduction velocities of muscle
    muscles 65-75m/sec

    nerve 3-5m/sec
  72. properties of excitable tissues:
    • amplitude (high enough to depolarize)
    • duration (long enough to excite)
    • speed of rise (rapid to prevent accomodation)
  73. frequency of motor level stimulation at which smooth tetanic contraction is produced (30-50 pps)
    fusion frequency
  74. continuous or uninterrupted unidirectional flow of charged particles
    direct current
  75. the continuous or uninterrupted bidirectional flow of charged particles
    alternating current
  76. the uni- or bidirectional flow of charged particles which periodically cease for a finite period of time
    pulsed current (pulsatile or interrupted)
  77. an isolated electrical event separated by a finite time from the next event
  78. unidirectional current flow in a mono or bi directional current
  79. shape of the visual representation of pulsed current on a current/time plot
  80. descriptive characteristics of pulse or waveform
    shape, symmetry, balance
  81. maximum current value reached in a monophasic pulse or for any single phase of a biphasic pulse
    peak amplitude
  82. maximum current value measure from the peak of the first phase to the peak of the second phase of biphasic pulse
    peak to peak amplitude
  83. elapsed time between the beginning and the end of one phase
    phase duration
  84. elapsed time between the beginning and the end of all phases in a single pulse; on the clinical stimulators. often labeled width,
    pulse duration
  85. T/F Phase duration is synonymous with pulse duration in a monophasic pulse
  86. elapsed time between 2 successive phases of a pulse, also known as the intrapulse interval
    interphase interval
  87. the time for the leading edge of the phase to increase in amplitude from the 0 current baseline to peak amplitude of 1 phase
    rise time
  88. time integral of current for a single phase; represented by the area under a single phase waveform
    phase charge
  89. time integral of a single pulse for the current waveform over the entire pulse
    pulse charge
  90. time between end of one pulse and the beginning of the next pulse in a series, the time between successive pulses
    interpulse interval
  91. # of pulses per unit time (pps) on clinical stimulators, often called pulse rate
  92. IIIIII IiIiI
    _________ what type of modulation is this?
    ______ ______ why type of modulation is this?
  94. timing modulation:

    individual lines (pulses)
  95. timing modulation:

    packages of trains

    envelope of AC currents
  96. duty cycle =?
    on time/ on time + off time X 100
  97. conduction in normal propogation
    orthodronic conduction
  98. conduction in opposite propogation
    antidromic conduction
  99. sensory level stimulation
    -gait theory of analgesia

    higher frequency 80-125 pps

    feel buzzing, tingling, tapping
  100. motor level stimulation
    longer pulse duration

    lower frequency

    1-5 pps

    taps into endorphins for analgesia
  101. microshock
    when applied directly to heart with sufficient current intensity (V fib)
  102. macroshock
    applied from surface of the body thru skin, large amount of current needed
  103. Identify voltage needed to do damage
    respiratory/cardiac arrest
    involuntary jerking
    chemical burns

    respiratory/cardiac arrest--80mA

    involuntary jerking --80 mA

    chemical burns --DC

    coagulation --<5mA
  104. Therapeutic applications for DC current (4)
    wound/soft tissue healing

    denervated muscles


    electrodiagnostic testing
  105. Therapeutic applications for low AC current (7)
    battery TENS


    variable pulse generator

    pain modulation


    functional retraining

    fracture healing
  106. Therapeutic applications for high pulsed current (5)
    pain modulation

    tissue healing

    muscle re-ed

    edema control

    muscle strengthening (small muscles)
  107. therapeutic applications for interferential current (3)
    pain modulation

    edema control

    soft tissue healing