Influence of Noxious Electrical Stimulation on Chronic Pain From Knee Osteoarthritis

Summary

Knee osteoarthritis (OA) is the most common lower extremity joint pain condition, and it is estimated that 15 million people in the US are living with symptomatic knee OA and that more than half (8 million) are under 65 years of age. To that end, the Centers for Disease Control and Prevention strongly recommends non-pharmacological treatments for chronic pain including physical therapy and weight loss; however, these interventions have significant barriers that can prevent their success. An intervention that targets pain specifically is transcutaneous electrical nerve stimulation (TENS), which is a low-cost intervention with evidence to support pain reduction. As used in the majority of research to date, the intervention called "TENS" refers to the application of electricity across the skin that produces a tingling sensation that is strong but comfortable. However, electricity is applied at a noxious level is thought to result in strong activation of the endogenous pain modulation system, thus producing longer-lasting pain inhibition. However, noxious electrical stimulation (NxES) has rarely been investigated as a treatment intervention. Recent studies, including our own, demonstrate that NxES produces immediate and potentially greater pain relief. Despite some promising research, the clinical use of NxES is sparse and more research is necessary to demonstrate its effects on resting pain, movement-related pain, physical function, and quality of life. The investigators hypothesize that the application of NxES will activate pain modulation mechanisms and change the pain modulation profile toward an anti-nociceptive state in adults with chronic knee osteoarthritis (OA) pain, and thereby decrease pain (at rest and with movement), improve physical function, and improve quality of life. The investigators expect individual differences; therefore, participants will be classified at baseline and their response to the intervention tracked using psychophysical tests and clinical response. The hypothesis will be tested through 2 Specific Aims.

Aim 1: The investigators will test the magnitude and duration of pain relief and functional improvement of a single treatment with NxES in adults with chronic knee OA pain.

Aim 2: The investigators will determine if repeated NxES treatments show greater pain relief and/or functional improvements and if so, whether the gains plateau after a certain number of treatments.

The knowledge gained by this study will be important to physical therapists and other health care practitioners who treat people with chronic knee osteoarthritic pain. If noxious electrical stimulation is found to be an effective strategy to decrease pain at rest and with movement, it may lead to improved patient care, improved function, and decreased chronic pain in people with knee osteoarthritis.

Conditions

• Knee Osteoarthritis

Interventions

DEVICE

Noxious Electrical Stimulation (NxES)

The NxES intervention will be applied with a pair of 2x3 inch electrodes placed orthogonally to the knee joint line with one electrode on the medial and lateral sides of the knee. The device is a commercially available unit(Chattanooga Continuum, DJO Global, Vista CA) and the parameters of the NxES include: 400 μs biphasic square wave pulses delivered at 50-100 pulses/second, using a cycle time of 10-seconds on, with a 2-second ramp-up in intensity, followed by a 10-second off period. The current intensity will be dosed over the first 2-minutes of stimulation to find the sensory perception threshold and the threshold for the first perception of a sharp, prickly buzzing sensation that they would identify as painful. Next, the current intensity will gradually be increased until the participant reports a sharp or prickly buzzing sensation that achieves a pain rating of not more than a 5/10 using a numeric pain rating scale.

Sponsors & Collaborators

• University of New England

  lead OTHER

Principal Investigators

• Scott K Stackhouse, PT, PhD · University of New England

Study Design

Allocation

NA

Purpose

TREATMENT

Masking

NONE

Model

SINGLE_GROUP

Eligibility

Min Age

50 Years

Max Age

90 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2021-08-02

Primary Completion

2022-12-31

Completion

2022-12-31

FDA Device

Yes

Countries

• United States

Study Locations