Exam 1 Flashcards
3 components of neuromuscular control
volitional contractions
reflex reactions
complex functional movements
definition of AMI
compromised ability to contract a muscle due to injury
what affects volitional muscle contractions (what can cause AMI)
swelling
pain
altered mechanoreceptor input
how does swelling impact muscle contractions
-may stimulate stretch receptors and trigger reflex inhibition
how does pain impact muscle contractions
-contributes to deficits in neuromuscular control
-painful exercise may slow recovery
pain -> inhibits muscle groups -> altered motor control -> change in movement pattern -> delayed recovery/increased risk of re-injury
how does altered input impact muscle contractions
-altered patterns may affect function
-ex: ankle: decreased position and balance sense, postural control; treatment: progressive balance/coordination exercises
what is used to address AMI after injury or surgery
neuromuscular electrical stimulation (NMES)
how does NMES work against AMI
developed to increase muscle strength
a nerve’s response to electrical stimulation is based on 3 factors
1) diameter of the nerve
2) depth of the nerve in relation to the electrode
3) phase duration of the current
which nerves are stimulated first
sensory nerves
which nerves are depolarized first
large-diameter nerves
exogenous contration
-NMES elicited
-entire motor unit stimulated to fatigue
-synchronous firing
-fatigues quickly (PC energy system)
-large diameter, fast-twitch fibers recruited first (low capacitance), slow twitch recruited once stimulation is increased
-GTO is excited
endogenous contraction
-physiological
-slow twitch fiber recruitment first
-asynchronous firing
-slow to fatigue
-slow twitch fibers excited first, fast-twitch are recruited if enough force is given (preserves energy)
-GTO causes inhibition = relax muscles from strong contraction
duty cycle for NMES
1:5 on to off time (10 seconds on, 50 seconds off)
-progress to 10:30
phase duration of NMES
250-300 us
pulse rate of NMES
35-50 pps
amplitude of NMES
produce strong, yet tolerable contractions
types of neuromuscular stimulation
russian
PENS
russian stimulation
-used for muscle reeducation
-patient contracts with the current, then relaxes
-preset parameters
-can produce a strong tetanus contraction
PENS
-patterned electrical neuromuscular stimulation: timed stimulation based on typical firing patterns (walking, running, jumping, etc)
-asymmetrical low-voltage pulsed current
-50 Hz pulse rate
-70 us phase duration
electrode placement of russian
bipolar: proximal and distal ends of the muscle
treatment duration of russian
10 cycles or until they are fatigued
ramp time of russian
2 seconds; time to reach full current
treatment of AMI with inhibited muscle
-apply NMES
-recruit motor neurons being reflexively inhibited
treatment of AMI with disinhibited muscle
-apply disinhibitory TENS (with therapeutic exercise) and cryotherapy
-decrease relative inhibitory activity and cause reflex activation of inhibited motor neuron
what causes denervation
trauma or disease
goal of NMES with denervation
overcome capacitance of the muscle
biofeedback
-does not produce a muscle contraction, visual or audio representation of a muscle contraction
-brings awareness of what muscles are being recruited with different movements
how many leads are required for EMG
2 active leads and a ground lead -> signal processed -> feedback
goal of EMG biofeedback
regain ability to contract the muscle
goal of NMES
restart motor efferent-proprioceptive feedback loop, induce contraction
-reconnect the neural loop from muscle to the brain
reflex responses
-progressively increase challenge to reflex responses to reduce rate of reinjury
-ex: balance on a training disk or wobble boards
-progress from reflex training to sport-specific
relaxation
-thought stopping, visual imagery, breathing exercises, isolated muscle contraction/relaxation
-may break the cycle of stress, pain, spasm
T/F the use of a mirror to provide visual feedback may assist with restoring neuromuscular control
true
example of a reflex reaction
quick movement of the foot after stepping on a lego
put in order how pain may be cause an increased risk of re-injury
pain -> inhibits muscle group -> altered motor control -> change in movement pattern -> increased risk of re-injury
T/F large diameter nerves correspond to fast-twitch fibers and fatigue quickly
true
an athlete who undergoes an arthroscopic partial menisectomy experiences a dramatic decrease in the ability to perform a quad set and straight leg raise the day after surgery, what has occurred
athlete is demostrating impaired control over volitional, isolated, quad muscle contraction
hip pain and arthritis may result in inhibition of what muscle
gluteus maximus
the restoration of neuromuscular control through the use of EMG biofeedback occurs
by restoring the loop between efferent output and afferent input into the CNS
example of AMI
inability to perform shoulder external rotation due to pain
inability to extend the knee after an ACL tear
contraindication to NMES
unstable fracture
T/F NMES is a efficient modality to increase muscle strength
true
what is ultrasound
deep-penetrating agent that produces changes in tissue through thermal and nonthermal (mechanical) mechanisms
-uses sound waves
uses of ultrasound
-diagnostic imaging
-*therapeutic deep tissue healing
-tissue destruction (break up kidney stones)
what depth is ultrasound used for in therapeutic deep tissue healing
1-3 W/cm^2
which MHz penetrates deeper in ultrasound
1 MHz penetrates deeper than 3 MHz
how are sound waves produced in ultrasound therapy
-alternating current travels through the coaxial cable into the transducer
-the current passes through the piezoelectric crystal which causes it to expand and contract which produces the sound waves
reverse piezoelectric effect
converts electrical energy into mechanical energy in the production of sound waves
what shape are ultrasound waves
sinusoidal (curvy up and down)
longitudinal waves
-molecule displacement occurs parallel to the direction of the sound
-travel through bone and soft tissue and liquid
transverse (shear) waves
molecule displacement occurs in a perpendicular to the direction of the energy
-created when a transverse waves strikes a bone
-cannot pass through fluids
Fresnel zone
-aka near field
-portion of the ultrasound beam used for therapeutic purposes
effective radiating area (ERA)
-proportion of the transducer’s surface area that produces ultrasonic energy (cm^2)
large ERAs
-produce collimated, focused beam
-used for treating a localized area such as a trigger point
smaller ERAs
-yield a divergent beam
-used for when treating a larger area like a muscle strain
frequency
-MHz
-how deep the waves penetrate
which frequency (MHz) ultrasound beam diverges more
1 MHz diverges more than 3 MHz
how deep does 1 MHz penetrate
about 5 cm
how deep does 3 MHz penetrate
2.5-3 cm
how to calculate treatment time
desired temp/heating rate
which frequency (MHz) has a longer treatment duration
1 MHz has a longer treatment duration that 3 MHz
spatial average intensity (SAI)
-amount of energy passing through the sound head’s ERA (W/cm^2)
total Watts (W)/ERA (cm^2)
100% continuous duty cycle
-always on and produces thermal effects
-used for tissues 5 cm or deepers
pulsed output duty cycle
-causes nonthermal (mechanical) effects
-decreases SAI, reduce thermal effects, increases proportion of nonthermal effects
thermal effects
-increase blood flow
-increase viscoelasticity
-increase inflammation
-increase muscle temp
how to calculate duty cycle
pulse length (on time)/ (pulse length (on) + pulse interval (on + off) *100
spatial average temporal peak intensity (SATP)
-avg intensity during the on time of the pulse
-total amount of energy delivered to the body during the treatment
spatial average temporal average intensity (SATA)
-measures the power of the ultrasonic energy delivered to the tissues over a given time (total watts/time)
output * duty cycle
beam nonuniformity ration (BNR)
-describes the variation between the peaks, the spatial intensity, and the valley
-low BNR increases risks of hot spots
-high BNR greater than 5:1
-low BNR less than 4:1
spatial peak intensity/spatial avg intensity
half-layer value
-depth where 50% of the ultrasonic energy has been absorbed by the tissues
attenuation
intensity of ultrasonic energy decreases as the distance it travels increases
-occurs through the scattering and absorption of the waves within the tissues
what happens to the ultrasound beam when it interacts with different tissue layers
some of the energy is reflected or refracted
-amount of reflection depends on the degree of change in density
-interface between soft tissue and bone is highly reflective
T/F ultrasound energy is affected by adipose tissues
false; the waves can easily pass through it
nonthermal effects
changes within the tissue resulting from the mechanical effect of ultrasonic energy
thermal effects
changes within the tissue as a direct result of ultrasound’s elevation of the tissue temp
what produces nonthermal effects that stimulate the healing process
acoustical streaming
cavitation
microstreaming
how does ultrasound effect the injury response process
-effects depend upon
–mode of application (continuous or pulsed)
–frequency of the sound
–size of treatment area
–vascularity and density of target tissues
–deep thermal effects
ultrasound effects on cellular response
-acoustical streaming and cavitation increases cell membrane permeability, changing the diffusion rate
-increased histamine release
-increased intracellular calcium
-mast cell degranulation
-increased rate of protein synthesis
thermal effects:
-increased cell metabolism
-accelerated rate of inflammation
ultrasound effects on inflammation
-changes in cell membrane permeability -> degranulation and release of growth factors and platelets -> fibroblasts proliferation
-creates new cells quicker to speed up the healing process
ultrasound effects on blood and fluid dynamics
continuous ultrasound increases blood flow, dilation of blood vessels, histamine release
ultrasound effects on nerve conduction and pain
-nerve conduction velocity increased from thermal effects
–increase pain threshold
-reduces activity of chemosensitve pain receptors
–increased blood flow
–increased capillary permeability
ultrasound effects on muscle spasm
-reduced mechanical and chemical triggers that continue the pain-spasm-pain cycle
–relaxation of muscle tension
–increase blood flow
–increase O2 delivery
–aiding in elongation of muscle fibers
ultrasound effects on tissue elasticity
-heats collagen-rich tissues, especially tendon, ligament, fascia, and scar tissue
-used for elongation of tissue
-have 3 minutes to stretch post-treatment
ultrasound effects on muscle and tendon healing
-1 MHz continuous output enhances release of preformed fibroblasts
-3 MHz increases cells ability to synthesize and secrete building blocks of fibroblasts
ultrasound effects on wound healing
-increase breaking strength of incisional wounds
-ultrasound used at 1 W/cm^2 may have an inhibitory effect on wound healing because necrotic tissue is unable to dissipate heat
ultrasound effects on fracture healing
low-intensity pulses ultrasouns applied in 1 20-min session per day has an improved healing rate for acute and nonunion fractures
-applied early in the healing process
phonophoresis
-assist in the diffusion of medication through the skin
-pushes meds deeper into the tissue
-cavitation is believed to cause small openings to increase pore size
-mix meds into the ultrasound gel
contraindications of ultrasound
-DVT
-areas of sensory deficit
-ischemic areas
-impaired circulations
-cancerous tumors
-active fractures
-metal or bony implants
-pregnancy
-joint replacements
-over fluid filled cavities
-over implanted pacemakers
-caution over vertebral column, nerve roots, and large nerve plexus
capacitance technique of diathermy
-patient places in an electric field, rapid rotation of dipoles results in mechanical friction and head production (heats subcutaneous fat)
inductance technique of diathermy
electric current through coiled wire creates electric current in tissue, heats the muscle
what temp does pulse diathermy heat
deep tissue 3-4 degrees C
contraindications/precautions of diathermy
-remove all metal from the patient
-avoid use near abdomen/back of pregnant women
-do not use in presence of infection, acute inflammation, open wounds, malignant tumors, large joint effusion
what currents does diathermy produce
eddy currents
pulse diathermy
-low frequency (<600 pps)
-short phase duration (65 us)
-nonthermal
-used for treatment of nonunion fractures, osteoarthritis, wound healing
you want to heat a deep tendon strain that is about 4.5 cm deep, what parameters would you use
1 MHz
what is the spatial average intensity if the power is 10 W and the ERA is 5 cm^2
10/5 = 2 W/cm^2
T/F longer treatment duration with ultrasound are needed for people with more adipose tissue
false
what causes nonthermal effects of ultrasound
acoustical streaming
cavitation
microstreaming
T/F pulsed diathermy may be used to heat deep tissue 3-4 degrees C
true
what is true about cavitation
-cavitation is associated with nonthermal effects of ultrasound
-cavitation involves the expansion and contraction of gas bubbles
-unstable cavitation refers to the collapse of these bubbles and can cause tissue damage
-stable cavitation facilitates fluid movement and membrane transport
definition of effective radiating area ERA
proportion of the transducer’s surface area that produces ultrasonic energy
definition of frequency
number of events which occur in 1 second
definition of power
unit of energy of ultrasound
definition of intensity
strength of the sound wave at a given location
definition of half-layer value
depth where 50% of the ultrasound energy has been absorbed
definition of duty cycle of ultrasound
percentage of time there is energy output during the ultrasound application
you have a basketball player come to you complaining of patellar tendon pain which started 2 days ago, you decide to perform ultrasound; what are the parameters
-output frequency: 3 MHz
-duty cycle: 20% (because it is acute injury)
-output intensity: 0.5 W/cm^2
-treatment duration: 4 min
T/F within a set time, a larger treatment area can be heated with diathermy than with ultrasound
true
ultrasound pass through soft tissue as what wave. when the ultrasound contacts bone the beam is transformed into what wave
longitudinal wave through soft tissue
transverse wave once it hits bone
true statements regarding phonophoresis
-similar to iontophoresis in that it drives meds through the skin
-it is noninvasive and spares the patient the fear of injections
-one must mix the active med with a good conducting gel
clinical use of therapeutic ultrasound
heat connective tissue before joint mob to increase ROM
precautions of ultrasound
-Changes in bowel or bladder habits
-A skin lesion lasting longer than 6 weeks
-Unusual bleeding or discharge
-Thickening or lump in the tissue
-Indigestion or difficulty swallowing
-Obvious changes in a mole or wart
-Nagging cough/hoarsness
nonmusculoskeletal relate symptoms that warrant a referral before ulrasound
-proximal or bilateral muscle weakness
-bilateral change in deep tendon reflex
-enlarged lymph nodes
-increased pain at night, night pain, sweating
-constant, intense pain
when to use 100% duty cycle
-continuous output for thermal effects
when to use a low duty cycle for ultrasound
-treat acute injured
-or when nonthermal effects are desired
ultrasound technque
-slowly move sound head
-area should be only 2-3 times the ERA/transducer’s head
-maintain contact with transducer and the skin
-continuous moving to prevent burns
-perform treatments within 5-10 minutes
direct coupling
-transducer is applied directly to the skin with the use of an ultrasound gel
pad (bladder) ultrasound method
-coat the gel pad/bladder both sides with ultrasound gel
-used for curved or irregular shaped areas in order to maintain full contact with the skin
immersion ultrasound technique
-body part is immersed in a tub of sterile or distilled water
-wipe away air bubbles
-place transducer in water about 1/2 inch from the body part
use of ultrasound and electrical stimulation at the same time
-ultrasound head serves as an electrode for stim
-slowly move the transducer to produce increased temp
-used for trigger points and superficial painful areas
-results in a muscle spasm or involuntary contraction
goal of diathermy
heat deeper tissue
-larger areas can be treated
indications for diathermy
-similar to ultrasound
-assist in restoring motion, functional gains, and return to play
contraindications for diathermy
-open wounds
-patients with internal fixation or arthroplasty
prep and treatment using diathermy
-patient is comfy
-remove jewelry and piercings
-skin is exposed and dry
-towel placed between skin and diathermy drum
-treatment time 15-20 minutes
-expect a warm sensation
low-intensity pulsed ultrasound (LIPUS) and pulsed electromagnetic field (PEMF)
-management of fractures
-no known adverse responses or contraindications
-treatment time based on manufacturer
-can be self administered
what does LASER stand for
light amplification of stimulated emission of radiation
low level laser therapy tissue temp remains below
36.5 degrees C
FDA approved used of LLLT
-minor chronic neck and shoulder pain (630 nm)
-carpal tunnerl (830 nm)
how is a laser produced
energy applied to an atom -> atom is excited -> atom returns to ground state -> energy released as a photon
amplification
photon generation leads to an increased amount of light energy
properties of laser light
monochromic
coherent
collimated
monochromic
one color or wavelength specific to the energy level of the photon
coherent
all waves of light energy at the same length and travelling in a similar phase relationship
collimated
beam remains parallel with distance
what are examples of type 1 lasers
laser printers
CD players
what are examples of type 2 lasers
bar code scanners
-lasers that do not exceed AEL of 1 mW
what are examples of type 3a lasers
laser pointers
-AEL of less than 5 mW, medium power
what are examples of type 3b lasers
LLLT
-AEL between 5 and 500 mW
what are examples of type 4 lasers
hazard to eyes and skin
-AEL above 500 mW
helium-neon lasers
-6-10 mm depth of penetration
-indicated for superficial wound care and dermatological problems
indium-gallium-aluminum-phosphide laser
-semiconductor, less coherence than gas lasers
-indicated for superficial wound care and dermatological problems
gallium-arsenide laser
-30-50 mm depth penetration
-indicated for tendinopathies, osteroarthritis
gallium-aluminum-arsenide laser
-increased power output = shorter treatment times
-indicated for deeper ligament and tendon injuries
combination probes
LED and laser
power density of LLLT
-irradiance or intensity of the beam
-how much power is going through the beam diameter
intensity = power/beam diameter
average power of LLLT
-continuous or pulse-train (burst) frequency mode
avg power = peak output power * duty cycle
treatment duration of LLLT
-dependent on total energy
-potential for skin burns if power is doubled
energy density or dosage of LLLT
-amount of energy applied per unit of area
-measured in joules
treatment frequencies of LLLT
-3-4/wk with moderate dose may be more effective than high dose fewer times a week
-cumulative effect: small doses over time
how does LLLT effect ATP production
-chromphores or photoacceptors (in the mitochondria) absorb photons
-> increase oxidative metabolism
-increased ATP production leads to synthesis of new cells responsible for repairing damaged tissue
how does LLLT effect nitric oxide release
-laser may assist in the release of NO (photodissociation)
-allows O2 to bind and produce ATP
how does LLLT effect reactive oxygen species (ROS)
-metabolic by-product of oxygen use in mitochondria
-laser may be lower levels of ROS
T/F LLLT may promote normal cellular function rather than changing cell function
true
an 830 nm laser would fall into which wave category
IR waves
if you want to treat shoulder pain, which wave length would you select
630 nm
T/F gallium-arsenide lasers can be used on deep ligaments
false
what is a physiological effect of LLLT
increased oxidative capacity
what is a photon
particle of light
what classifications of laser can cause harm to skin and eyes therefore must wear goggles during treatment
3b and above
how does chromoreceptors/photoacceptors increase healing time
absorb photons -> increase oxifative metabolism -> provide energy to the cell -> increases the healing time
what are reactive oxygen species (ROS)
waste products
-needs to be eliminated in order to increase number of healthy cells
goal of LLLT
promote healing and reduce pain
tips for effective application of LLLT
-perpendicular, firm contact (unless open wound)
-gradually increase dosage
-inquire about patient’s sensations and post-treatment changes
-adjust dosage in response to previous treatment
application techniques of LLLT
-point application: applied directly over a trigger point, like acupuncuture
-scanning: slow and steady over an area
-grid: draw squares and point at each one
indications for LLLT
-inflammaiton
-pain
-wound healing
-blood circulation
-muscle function
-adjunctive therapy
how does LLLT effect inflammtion
-inhibit cyclooxygenase 2, reduce prostaglandin E2
-combine with POLICE to reduce inflammation
how does LLLT effect pain
-production of endogenous opiates, NO, serotonin, ACh
-effect on nerve conduction velocity and somatosensory evoked potential
-increase NO = increase O2
-endogenous opiates released during descending mechanism (pain inhibitoin)
-serotonin released during descending to also inhibit pain
-ACh inhibitory neurotransmitter, increases pain threshold
how does LLLT effect wound healing
-treatment of ulcers and other skin injuries
-biomodulation: stimulate or inhibit
–stimulates wound healing by increasing good cells
–inhibits bacterial/viral growth and spread
-possible systemic effects
how does LLLT effect blood circulation
-increase blood flow and dose-response effect
-needs additional research
how does LLLT effect muscle function
-increase ATP production
-reported effects related to delaying fatigue during and improving recovery after exercise
how does LLLT effect adjunctive therapy
-cool tissues before LLLT and heat after
-may not benefit from combo treatments or while on certain meds
safety considerations with LLLT
-eye safety: never look into the laser, wear eye protection
-training: proper training required
-cell proliferation: determine appropriate dosage for child vs adult
-fatigue reactions: usually short-term
-pain response: may occur the following day, positive response sign
contraindications of LLLT
-pregnancy
-cancer
-children
-steroid usage (topical steroids may burn them)
T/F moving LLLT over an affected area is similar to ultrasound
true
which gate control mechanism does LLLT evoke
descending mechanism
