Home-Based Quadriceps Isometric Exercise for Knee Osteoarthritis Pain (KOA-ISO01)

February 26, 2026 updated by: Universidad del Valle de México, Campus Cuernavaca

Home-based Quadriceps Isometric Exercise as a First-Line Rehabilitation Strategy for Knee Osteoarthritis Pain in Community-Dwelling Older Adults: A Randomized Factorial Pilot Trial

Knee osteoarthritis is a common cause of pain and reduced mobility in older adults. Many people have limited access to supervised rehabilitation programs, highlighting the need for simple and safe home-based treatment options.

This study evaluates whether a brief home-based quadriceps isometric exercise program can reduce knee pain in community-dwelling older adults. Participants perform short daily muscle contractions of the thigh muscles for 28 days. In addition, participants are assigned to receive one of four topical formulations (placebo, cannabidiol, arnica, or a combination of cannabidiol and arnica) to explore whether these products modify the exercise response.

The primary outcome is change in knee pain intensity measured using a visual analog scale. Secondary outcomes include adherence and safety. This pilot study aims to assess the feasibility, safety, and preliminary effectiveness of this low-cost and easily accessible strategy to inform future larger clinical trials.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

This study is a prospective randomized 4×2 factorial pilot trial conducted in community-dwelling older adults with symptomatic knee osteoarthritis. The purpose is to evaluate the feasibility, safety, and preliminary effectiveness of a brief home-based quadriceps isometric exercise program for short-term pain reduction, and to explore whether topical cannabidiol (CBD), arnica, or their combination modify the exercise response.

Participants are randomly assigned to one of four topical treatment groups (placebo, CBD, arnica, or CBD + arnica) and stratified to either an exercise or no-exercise condition, resulting in eight factorial subgroups. Randomization is computer-generated with allocation concealment using sequentially numbered opaque sealed envelopes.

The intervention period lasts 28 days. Participants allocated to the exercise condition perform daily quadriceps isometric contractions at home consisting of three sets of 10-second near-maximal voluntary contractions with rest intervals, requiring approximately 6 minutes per day. Topical formulations are applied twice daily to the affected knee. Adherence is monitored using daily logs.

The primary outcome is change in knee pain intensity measured using a Visual Analog Scale (VAS) at day 28. Secondary outcomes include feasibility indicators (adherence and retention), safety (adverse events), and exploratory changes in anthropometric and body composition measures.

Analyses are exploratory and include factorial ANCOVA adjusted for baseline values to estimate main effects of exercise and topical treatment, as well as interaction effects. Effect sizes are calculated to aid clinical interpretation.

As a pilot study, results are intended to inform the design and sample size estimation of future adequately powered randomized controlled trials evaluating low-cost, home-based rehabilitation strategies for older adults with knee osteoarthritis.

Study Type

Interventional

Enrollment (Actual)

50

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Mexico
    • Morelos
      • Xochitepec, Morelos, Mexico, 62790
        • Hospital Regional de Alta Especialidad "Centenario de la Revolución Mexicana" - ISSSTE, Servicio de Alimentación y Nutrición Clínica

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Adults aged 65 years or older

Clinical diagnosis of chronic knee osteoarthritis according to American College of Rheumatology criteria

Knee pain for ≥3 months

Baseline knee pain intensity ≥4 on a 10-cm Visual Analog Scale (VAS)

Ability to walk independently with or without assistive devices

Ability to understand study procedures and provide written informed consent

Exclusion Criteria:

  • Recent knee surgery or intra-articular injection within the last 3 months

Planned knee surgery during the study period

Severe neurological or cardiovascular conditions limiting exercise participation

Skin lesions or hypersensitivity to topical formulations

Current use of topical analgesics on the target knee

Cognitive impairment preventing adherence to the protocol

Participation in another clinical trial within the last 30 days

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Factorial Assignment
  • Masking: Single

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Arm Title Placebo Topical + Isometric Exercise
Participants received placebo topical gel twice daily plus daily home-based quadriceps isometric exercise for 28 days.
Drug: Placebo Topical Gel
Placebo topical formulation without active pharmacological ingredients, applied twice daily to the affected knee for 28 days.
Behavioral: Home-based Quadriceps Isometric Exercise
Daily home-based quadriceps isometric exercise protocol consisting of three sets of 10-second near-maximal voluntary contractions with rest intervals, performed for 28 days.
Experimental: Placebo Topical Only
Participants received placebo topical gel twice daily without exercise.
Drug: Placebo Topical Gel
Placebo topical formulation without active pharmacological ingredients, applied twice daily to the affected knee for 28 days.
Experimental: CBD Topical + Isometric Exercise
Participants received cannabidiol topical formulation twice daily plus daily home-based quadriceps isometric exercise.
Behavioral: Home-based Quadriceps Isometric Exercise
Daily home-based quadriceps isometric exercise protocol consisting of three sets of 10-second near-maximal voluntary contractions with rest intervals, performed for 28 days.
Drug: Cannabidiol (CBD) Topical Gel
Topical cannabidiol formulation applied twice daily to the affected knee for 28 days.
Experimental: CBD Topical Only
Participants received cannabidiol topical formulation twice daily without exercise.
Drug: Cannabidiol (CBD) Topical Gel
Topical cannabidiol formulation applied twice daily to the affected knee for 28 days.
Experimental: Arnica Topical + Isometric Exercise
Participants received Arnica montana topical formulation twice daily plus daily home-based quadriceps isometric exercise.
Behavioral: Home-based Quadriceps Isometric Exercise
Daily home-based quadriceps isometric exercise protocol consisting of three sets of 10-second near-maximal voluntary contractions with rest intervals, performed for 28 days.
Drug: Arnica montana Topical Gel
Topical Arnica montana formulation applied twice daily to the affected knee for 28 days.
Experimental: Arnica Topical Only
Participants received Arnica montana topical formulation twice daily without exercise.
Drug: Arnica montana Topical Gel
Topical Arnica montana formulation applied twice daily to the affected knee for 28 days.
Experimental: CBD + Arnica Topical + Exercise
Participants received combined cannabidiol and Arnica montana topical formulation twice daily plus daily home-based quadriceps isometric exercise.
Behavioral: Home-based Quadriceps Isometric Exercise
Daily home-based quadriceps isometric exercise protocol consisting of three sets of 10-second near-maximal voluntary contractions with rest intervals, performed for 28 days.
Drug: CBD + Arnica Topical Gel
combined cannabidiol and arnica formulation applied twice daily
Experimental: CBD + Arnica Topical Only
Participants received combined cannabidiol and Arnica montana topical formulation twice daily without exercise.
Drug: CBD + Arnica Topical Gel
combined cannabidiol and arnica formulation applied twice daily

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change from baseline in knee pain intensity measured by Visual Analog Scale (VAS)
Time Frame: Baseline to Day 28
Knee pain intensity will be assessed using a 10-cm Visual Analog Scale (VAS) ranging from 0 (no pain) to 10 (worst imaginable pain). The primary endpoint is the change from baseline to Day 28. Higher scores indicate greater pain.
Baseline to Day 28

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change from baseline in quadriceps isometric strength
Time Frame: Baseline to Day 28
Maximal voluntary isometric quadriceps strength will be measured using handheld dynamometry. The outcome will be expressed as peak force (kg or N). Change from baseline to Day 28 will be analyzed.
Baseline to Day 28
Change from baseline in body composition
Time Frame: Baseline to Day 28
Lean mass and fat mass will be assessed using bioelectrical impedance analysis. Change from baseline to Day 28 will be evaluated.
Baseline to Day 28
Exercise and topical treatment adherence
Time Frame: Throughout the 28-day intervention
Adherence will be calculated as the percentage of prescribed sessions/applications completed according to daily logs.
Throughout the 28-day intervention
Adverse events
Time Frame: Baseline to Day 28
Frequency and type of adverse events related to topical formulations or exercise will be recorded.
Baseline to Day 28

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Universidad del Valle de México, Campus Cuernavaca

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

September 1, 2025

Primary Completion (Actual)

September 1, 2025

Study Completion (Actual)

November 1, 2025

Study Registration Dates

First Submitted

February 10, 2026

First Submitted That Met QC Criteria

February 26, 2026

First Posted (Actual)

March 3, 2026

Study Record Updates

Last Update Posted (Actual)

March 3, 2026

Last Update Submitted That Met QC Criteria

February 26, 2026

Last Verified

February 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • UVM-KOAISO-01-2025

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

Individual participant data will not be shared due to institutional privacy policies and protection of patient confidentiality.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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