Week 6 Review Flashcards
Electrical stimulation to produce contractions of innervated muscles is known as:
NMES
What is the purpose of a ramp-up time?
for patient comfort
The minimum MVIC (Max Volitional Isometric Contraction) force required for strengthening healthy muscle using NMES is:
50% of MVIC
When the goal for NMES is to increase strength, what ratio of on:off time should be used initially?
1:5
If the muscle twitches, instead of producing a strong contraction, what parameter should you change?
frequency
This type of current is required for denervated muscle to contract
direct current
With electrically stimulated contractions, the contraction force can be increased by increasing the total amount of current, which can be achieved by (select all that apply):
-increasing the pulse duration
-increasing the current amplitude
-increasing the electrode size (using larger electrodes)
NMES to the quadriceps can improve muscle strength but does little to improve functional outcomes in patients with reduced physical activity, muscle atrophy, and loss of strength associated with progressive or critical illness.
False (NMES to the quadriceps can improve muscle strength AND functional outcomes in patients with reduced physical activity, muscle atrophy, and loss of strength associated with progressive or critical illness.)
In general, whether the contraction is stimulated by electrical stimulation or done voluntarily, strength gains in healthy muscle depends on the force of the contraction. For strength gains to occur, the contraction must be at least ___ of the maximum voluntary isometric contraction (MVIC) force.
50%
In general, in terms of the pulse duration setting for stimulating muscle contraction, ___ durations are usually more comfortable for stimulating smaller muscles, and ___ durations are more comfortable for stimulating larger muscles.
shorter; longer
For NMES, selection of the ideal combination of pulse duration and current amplitude should be based on patient comfort and achievement of the desired outcome.
true
When applying NMES to stimulate a muscle, you notice that the contraction is very twitchy (as opposed to a smooth tetanic contraction). The electrode placement and size are correct, as well as the pulsed biphasic waveform. In this case, what setting is the most likely cause for a twitchy contraction?
the frequency is too low
For NMES, a frequency of at least ___ is needed to produce a sustained contraction. A frequency of ___ is generally recommended to produce a smooth tetanic contraction without causing rapid fatigue.
30 pps; 35-50 pps
When the goal of e-stim is to relieve a muscle spasm, the on:off ratio is set at ___, with both on and off times set between ___. These settings will produce muscle fatigue and relax the spasm.
1:1; 2-5 seconds
When e-stim is used for muscle strengthening, it is generally recommended that treatment last long enough to allow for ___ contractions. This will usually take about ___.
10-20; 10 minutes
When applying NMES for a muscle contraction, a commonly overlooked setting that is often the culprit of a poor contraction is:
electrode placement
Application of an electrical current to produce muscle contractions that are applied during a functional activity. Examples of this include the electrical stimulation of dorsiflexion during the swing phase of gait and the stimulation of write extension and finger flexion during grasp activities.
Which of the following terms does the above definition describe:
FES
Increases in strength of the quadriceps following the first 2 weeks of neuromuscular electrical stimulation (NMES) treatments are most likely secondary to which of the following?
Changes in motor unit recruitment
Which of the following is the key factor in the efficacy of NMES strengthening protocols?
intensity of training
Which of the following parameters can be increased to help limit fatigue during NMES?
off - time
Electrode placements for NMES applications depend on which of the following?
Size and location of the targeted muscle
An advantage of NMES recruitment of muscle fiber type compared to voluntary recruitment is which of the following?
Activation of fast fibers at lower contraction intensities
Which parameters would most likely be effective when the goal of NMES is to enhance strength?
75 pps, 10 seconds on : 50 seconds off, 10 minutes
Select an appropriate electrode placement for ambulation assist in a person with decreased active dorsiflexion during the swing phase of gait.
Peroneal nerve and anterior tibialis muscle belly
