Pain
Conditions
Brief summary
The purpose of this study is to determine if changing the frequency or intensity of transcutaneous electrical nerve stimulation (TENS) can reduce the development of tolerance to TENS treatment.
Detailed description
Healthy adults will come daily for 5 consecutive days to the testing room. Pressure pain thresholds (PPT) will be the outcome measure and will be used to measure the subject's pain threshold to deep mechanical pressure. Subjects will push a button to stop the PPT test when they first begin to feel a sensation of pain. The PPT test will be done before TENS application. The TENS unit will be applied based on random assignment to 1 of 5 treatment types and subjects will not be told which group they are assigned to. Those groups are: 1) placebo TENS, 2) high frequency TENS, 3) alternating frequency TENS, 4) modulated frequency TENS, or 5) high frequency TENS with increased intensity daily. The TENS unit will be applied for 30 minutes. After 20 minutes the PPT test will be completed a second time. This procedure will occur on all 5 consecutive days of testing. Data will be measured and recorded by an assessor blind to subject group. Blinding will be assessed at the end of testing on day 5.
Interventions
Transcutaneous electrical nerve stimulation (TENS) is utilized clinically by a variety of health care professionals for the reduction of pain. The mechanisms by which TENS produces analgesia or reduces pain are only recently being elucidated. TENS is a non-invasive modality that is inexpensive, safe and easy to use with relatively few contraindications. Frequency of stimulation is broadly classified as high frequency (\>50Hz), low frequency (\<10Hz) TENS. Intensity is determined by the response of the patient as either sensory level (low-intensity) TENS strong but comfortable. With sensory level TENS, the voltage (i.e. amplitude) is increased only until the patient feels a comfortable tingling (perceived with high frequency) or tapping (perceived with low frequency) sensation without motor contraction. With strong but comfortable TENS the intensity is increased to a strong but comfortable level which may include muscle contraction.
Sponsors
Study design
Intervention model description
Randomized controlled trial -double blind
Eligibility
Inclusion criteria
* 18-65 Years of Age (YOA) * no current pain condition
Exclusion criteria
* Pregnancy * Cardiac pacemaker * Currently experiencing pain * Abnormal sensation in dominant forearm * History of seizures * Prior TENS use
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Pressure Pain Threshold | Pre TENS and post TENS at initial (day 1) and final (day 5) study visit | Pressure pain thresholds (PPTs) change score measured in kilopascal (kPa) will be assessed on the forearm using a pressure algometer. The pressure algometer is mechanical pressure applied by the research assistant at a gradual rate by pushing the device against the skin. The device has a 1 cm2 pad that is in contact with the skin. The subject has a button that they push when the pressure first becomes painful (threshold)which stops the test and the pressure amount is recorded by the research assistant. This is the amount of pressured in kPa that is required to cause a subjective pain of 1/10 on a scale of 0 (no Pain) to 10 (Maximum Pain) rating by the subject. The change score from day 1 to Day 5 is the primary outcome measure. |