Efficacy of Artificial Intelligence-Assisted Therapeutic Exercise in Patients With Knee Osteoarthritis (ET-AIAR)

Efficacy of Artificial Intelligence-Assisted Therapeutic Exercise in Patients With Knee Osteoarthritis: A Randomized Controlled Clinical Trial

Knee osteoarthritis is a common, chronic degenerative condition that causes pain, functional limitations, and reduced quality of life, especially in adults older than 50 years. Although clinical practice guidelines recommend therapeutic exercise and physical therapy as the first-line treatment, many patients do not receive or adhere to the recommended programs. Digital health tools may help expand access and improve adherence by supporting home-based exercise.

This study is a parallel-group, randomized controlled clinical trial designed to evaluate the effectiveness of an artificial intelligence (AI)-assisted therapeutic exercise program delivered through a web-based app compared with a conventional home exercise program provided on paper in adults with knee osteoarthritis. The primary goal is to determine whether the AI-assisted program produces greater improvements in pain and knee-related function. Secondary goals include assessing changes in health-related quality of life and patient-perceived overall improvement, and comparing implementation outcomes like adherence, usability, satisfaction, self-efficacy for exercise, and use of the prescribed exercise resource (paper vs web platform). Participants will be recruited from the Department of Physical Medicine and Rehabilitation at Hospital Universitario 12 de Octubre and randomly assigned to either the AI-assisted exercise group or the conventional exercise group. The AI-assisted web app will adjust exercise dose and progression based on participant-reported pain and perceived exertion, using decision rules informed by clinical practice guidelines and high-quality research evidence. Both groups will complete a 6-week home-based exercise program and will also attend weekly in-person group sessions that will be held separately by study arm (experimental and control groups will not mix) to reduce cross-contamination and support masking procedures. These sessions will be used to address questions, reinforce the protocol, and monitor for adverse events. Clinical outcomes will include pain intensity (visual analog scale), knee-related disability and function (WOMAC), health-related quality of life (EQ-5D), and patient global rating of change (GROC). Physical performance outcomes (30-second Chair Stand Test and Stair Climb Test) will be assessed at baseline and 1 week after completion of the 6-week intervention. Assessments will be conducted at baseline, one week after the 6-week intervention, and at 3 and 6 months after the intervention, with the exception of physical performance outcomes, which will be assessed at baseline and 1 week post-intervention.

Study Overview

• Status: Recruiting
• Conditions: Knee Osteoarthritis
• Intervention / Treatment: Other: AI-Assisted Exercise Program; Other: Paper-Based Home Exercise Program

• Study Type: Interventional
• Enrollment (Estimated): 84
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Spain
  • Madrid
    • Madrid, Madrid, Spain, 28041
      • Recruiting
      • Hospital Universitario 12 de Octubre
      • Contact: Marcos José N Marcos José Navarro-Santana; Phone Number: 0034 91 394 15 24; Email: marconav@ucm.es

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria (based on National Institute for Health and Care Excellence (NICE) guidance):

• Clinical criteria for KOA: age ≥45 years, activity-related knee pain, and morning knee stiffness lasting ≤30 minutes.
• Knee pain for 3 months or longer.
• Knee pain on most days during the previous month.
• Overall knee pain intensity ≥4 on an 11-point Numerical Rating Scale (NRS; 0-10) during the previous week.
• Ownership of a smartphone and ability to use a mobile application.
• Internet access at home and/or via the mobile phone.
• Ability to provide informed consent, participate, and complete study assessments.

Exclusion Criteria:

• Having a planned knee arthroplasty (knee replacement) surgery.
• Knee prosthesis/arthroplasty in the most painful knee.
• Participation in a therapeutic exercise program for knee osteoarthritis within the past 6 weeks.
• Infiltration for knee osteoarthritis within the past 12 weeks.
• Inflammatory arthritic conditions.
• A fall in the past 12 months without medical clearance to perform unsupervised home exercise.
• Being homebound during the past month without medical clearance to perform unsupervised home exercise.
• Failing the pre-exercise screening and not having medical clearance to perform unsupervised home exercise.
• Inability to communicate in Spanish.
• Any neurological or systemic disease that may limit participation in the study.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: AI-Assisted Therapeutic Exercise (Web App); Participants will complete a 6-week home-based therapeutic exercise program delivered through an AI-assisted web application. The program will be individualized and updated based on participant-reported pain and perceived exertion, which will be used to guide exercise dose and progression (e.g., progression/regression, load adjustments, and exercise variants) according to guideline-informed decision rules embedded in the platform. Participants will also attend weekly in-person, arm-specific group sessions (experimental-only) for protocol reinforcement, questions, and adverse event monitoring.	Other: AI-Assisted Exercise Program; Participants will complete a 6-week home-based therapeutic exercise program delivered through an AI-assisted web application. The program will be individualized and updated based on participant-reported pain and perceived exertion, which will be used to guide exercise dose and progression (e.g., progression/regression, load adjustments, and exercise variants) according to guideline-informed decision rules embedded in the platform. Participants will also attend weekly in-person, arm-specific group sessions (experimental-only) for protocol reinforcement, questions, and adverse event monitoring.
Active Comparator: Usual Care (Paper-Based Home Exercise Program); Participants will complete a 6-week home-based therapeutic exercise program provided in paper format (printed exercise materials). The program will follow a conventional, predefined progression consistent with usual care and will not incorporate real-time, individualized adjustments based on symptom/effort inputs. Participants will also attend weekly in-person, arm-specific group sessions (control-only) for protocol reinforcement, questions, and adverse event monitoring.	Other: Paper-Based Home Exercise Program; Participants will complete a 6-week home-based therapeutic exercise program provided in paper format (printed exercise materials). The program will follow a conventional, predefined progression consistent with usual care and will not incorporate real-time, individualized adjustments based on symptom/effort inputs. Participants will also attend weekly in-person, arm-specific group sessions (control-only) for protocol reinforcement, questions, and adverse event monitoring.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Pain Intensity	Pain intensity will be assessed using the Numeric Pain Rating Scale (NPRS), a single 11-point numerical rating scale widely validated across different patient populations, where 0 represents no pain and 10 represents the worst possible pain. Data obtained through the NPRS are easy to document, intuitively interpretable and meet regulatory requirements for pain assessment and documentation.	Baseline, 1 week post-intervention, 3 months post-intervention and 6 months post-intervention

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Disability	Pain, stiffness and self-reported physical function will be assessed using the Western Ontario and McMaster Universities Osteoarthritis Index short form (WOMAC-SF), a patient-reported outcome measure designed to quantify symptom severity and functional limitations typically associated with hip and knee osteoarthritis. Items will be summed to obtain a total score ranging from 0 to 44 points, where higher results indicate worse symptoms and greater functional limitation.	Baseline, 1 week post-intervention, 3 months post-intervention and 6 months post-intervention
Health-related quality of life	Health-related quality of life will be assessed using the EuroQol EQ-5D-5L, a standardized, generic measure of self-reported health status widely used in clinical and health-economic research. The EQ-5D-5L comprises two components: (1) a descriptive system and (2) a visual analogue scale (EQ VAS). The descriptive system covers five dimensions: mobility, self-care, usual activities, pain/discomfort, and anxiety/depression, each rated across five severity levels (from no problems to extreme problems). Responses are combined into a 5-digit health state (e.g., 11,121), which is then converted into a single utility index using a country-specific value set; in this study, the Spanish value set will be applied for index derivation. The EQ VAS records the participant's overall health "today" on a 0-100 scale, where 0 represents the worst imaginable health and 100 the best imaginable health. The EQ-5D-5L has demonstrated validity and provides reference norms for the Spanish population.	Baseline, 1 week post-intervention, 3 months post-intervention and 6 months post-intervention
Lower-limb functional performance	Lower-limb functional performance will be assessed using the 30-Second Chair Stand Test (30CST), a pragmatic, clinic-friendly measure of functional strength and endurance of the lower extremities. In this test, participants will be instructed to rise to a full stand and sit down as many times as possible within 30 seconds, starting from a standard chair (without armrests), with arms crossed over the chest (or following a standardized alternative if needed for safety). The primary outcome is the number of fully completed sit-to-stand repetitions in 30 seconds, where higher values indicate better functional performance.	Baseline and 1 week post-intervention
Lower-limb stair-climbing function	Lower-limb stair-climbing function will be assessed using a Timed Stair Test consisting of 11 steps, a pragmatic measure of lower-extremity functional capacity during stair ascent and descent. Participants will be instructed to ascend and then descend a flight of 11 stairs as quickly and safely as possible, starting from a standardized position. The primary outcome will be time to completion (seconds), recorded from the initiation of movement to the moment the participant returns to the starting level after completing both ascent and descent; shorter times indicate better lower-limb function.	Baseline and 1 week post-intervention
Perceived overall change (Patient Global Rating of Change, GROC)	Participants' perceived overall change will be assessed using the Patient Global Rating of Change (GROC), a single-item anchor measure designed to capture the participant's global perception of improvement or deterioration since baseline. Participants will be asked to rate how their condition has changed compared with the start of the study on a 15-point scale ranging from -7 to +7, where -7 indicates "a very great deal worse," 0 indicates "no change," and +7 indicates "a very great deal better." The primary outcome will be the GROC score at each follow-up, with positive values reflecting improvement and negative values reflecting worsening.	1 week post-intervention, 3 months post-intervention and 6 months post-intervention

Collaborators and Investigators

• Sponsor: Universidad Complutense de Madrid
• Collaborators: Hospital Universitario 12 de Octubre

Study record dates

Study Major Dates

• Study Start (Actual): May 13, 2026
• Primary Completion (Estimated): March 15, 2027
• Study Completion (Estimated): March 15, 2027

Study Registration Dates

• First Submitted: February 19, 2026
• First Submitted That Met QC Criteria: February 19, 2026
• First Posted (Actual): February 25, 2026

Study Record Updates

• Last Update Posted (Actual): May 18, 2026
• Last Update Submitted That Met QC Criteria: May 13, 2026
• Last Verified: February 1, 2026

More Information

Terms related to this study

• Keywords: osteoarthritis; exercise; knee; digital intervention
• Additional Relevant MeSH Terms: Musculoskeletal Diseases; Arthritis; Joint Diseases; Rheumatic Diseases; Behavior; Osteoarthritis; Osteoarthritis, Knee; Motor Activity
• Other Study ID Numbers: 25/753

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No