Placebo Topical Gel
Placebo topical formulation without active pharmacological ingredients, applied twice daily to the affected knee for 28 days.
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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.
Locally preserved from ClinicalTrials.govOpen ClinicalTrials.govlast source update 2026-03-03
What this record can show
This locally preserved record separates the registered protocol from source-reported registry results. Neither is a treatment recommendation.
Registry facts
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.
Linked local records
Local links use governed condition terms or exact source-reported intervention names. They are navigation candidates, not efficacy claims.
Interventions
Placebo topical formulation without active pharmacological ingredients, applied twice daily to the affected knee for 28 days.
Topical cannabidiol formulation applied twice daily to the affected knee for 28 days.
Topical Arnica montana formulation applied twice daily to the affected knee for 28 days.
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.
combined cannabidiol and arnica formulation applied twice daily
Eligibility
primary outcomes
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.
secondary outcomes
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.
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.
Time frame: Throughout the 28-day intervention
Adherence will be calculated as the percentage of prescribed sessions/applications completed according to daily logs.
Time frame: Baseline to Day 28
Frequency and type of adverse events related to topical formulations or exercise will be recorded.
Publications
No exact PMID-linked public article is currently readable locally.