Mobile-Based Telerehabilitation With Sensors for Adherence and Efficacy in Chronic Patellofemoral Pain: A Randomized Controlled Trial

This study is a prospective, single-center trial involving 174 patients diagnosed with patellofemoral pain. The study adhered to ethical guidelines and obtained informed consent from all participants. Participants were randomly assigned to receive face-to-face remote rehabilitation guidance either 1 time, 3 times, or 6 times. The primary outcome was device-recorded training adherence, defined as cumulative total training time (hours) and mean weekly training time (hours/week) over the first 6 weeks of independent home-based telerehabilitation.Self-reported adherence was measured using the Exercise Adherence Rating Scale (EARS) at week 6 (i.e., 6 weeks after the participant completed their final face-to-face tutorial).ain intensity during daily activities and squatting at 60° was measured using the Visual Analog Scale (VAS; 0-10);7 quadriceps muscle strength (concentric and eccentric peak torque) was evaluated using isokinetic dynamometry; knee function was assessed with the Kujala Patellofemoral Score (0-100); fatigue was measured using the Fatigue Severity Scale (FSS; 9 items, 7 points each). Additionally, a closed-ended adherence survey captured participant perceptions of factors influencing adherence

Study Overview

• Status: Completed
• Conditions: Patellofemoral Pain
• Intervention / Treatment: Device: one session of face-to-face telerehabilitation tutorial (OST); Device: Three session of face-to-face telerehabilitation tutorials (TST); Device: Six session of face-to-face telerehabilitation tutorials (SST)

Detailed Description

The inestigators conducted a forward-looking, single-center pilot study with a follow-up period of 8 weeks. The study recruited 174 patients diagnosed with patellofemoral pain (PFP) by a professional sports physician at the Department of Sports Medicine, Peking University Third Hospital, between June and August 2024. The study adhered to the principles of the Declaration of Helsinki and was approved by the Research Ethics Committee of Peking University Third Hospital. Although this is a pilot study, the inestigators strictly followed the CONSORT guidelines. All participants signed an informed consent form and completed home rehabilitation interventions.

Inclusion and Exclusion Criteria During the trial, an investigator not involved in the study used an electronically generated random sequence to assign patients to three groups. Two professional physical therapists (N.C and S.R) were responsible for assessing and supervising the accuracy of the project and were unaware of the grouping details.

Interventions After randomization, participants received a package containing two wearable motion sensors, a charger, resistance bands, and a manual. Additionally, the rehabilitation software provided lectures and Q&A sessions related to the condition, accessible via Android or iOS platforms. All data collected by the sensors were strictly encrypted to protect patient information and privacy. Each participant was assigned a therapist for home rehabilitation support, and a follow-up function via the software or telephone was used to remind patients who missed three remote rehabilitation sessions.

Before starting home rehabilitation, patients attended a briefing at the hospital. Participants were divided into three groups: Group 1 received 1 face-to-face remote rehabilitation tutorial (OST), Group 2 received 3 face-to-face remote rehabilitation tutorials (TST), and Group 3 received 6 face-to-face remote rehabilitation tutorials (SST). Each session lasted 40 minutes and was conducted three times a week (on Tuesday, Thursday, and Saturday). Following the briefing, patients performed home remote rehabilitation training on the same day, with each session lasting 40 minutes. The remote rehabilitation program included muscle strengthening, flexibility stretching, and movement quality training.

Primary Outcomes. The primary outcome was device-recorded training adherence, defined as cumulative total training time (hours) and mean weekly training time (hours/week) over the first 6 weeks of independent home-based telerehabilitation. Data recording commenced immediately after each participant completed his or her final face-to-face tutorial, thereby isolating adherence to the unsupervised home program. Because the three groups differed in the number of tutorials received, the calendar start date of the 6-week recording window varied: OST participants began the recording window after session 1; TST participants after session 3; and SST participants after session 6. The 6-week duration of the window was identical across groups.

Secondary Outcomes. Self-reported adherence was measured using the Exercise Adherence Rating Scale (EARS) at week 6 (i.e., 6 weeks after the participant completed their final face-to-face tutorial). The EARS comprises Section A (6 items assessing adherence to prescribed home exercise) and Section B (10 items exploring barriers to adherence). Items are rated on a 5-point Likert scale (0 = "strongly disagree" to 4 = "strongly agree"), with positively phrased items reverse scored such that higher scores indicate better adherence. The EARS has demonstrated good reliability (Cronbach α = .85) and construct validity. (Multimedia Appendix 3). Secondary engagement metrics, including frequency of question-and-answer visits and number of reminder alerts generated by the system, were recorded over the 6-week period and explored as surrogate indicators of self-management behavior but were not included in the primary adherence endpoint. Additional secondary outcomes were assessed at the 8-week endpoint: pain intensity during daily activities and squatting at 60° was measured using the Visual Analog Scale (VAS; 0-10);7 quadriceps muscle strength (concentric and eccentric peak torque) was evaluated using isokinetic dynamometry; knee function was assessed with the Kujala Patellofemoral Score (0-100); fatigue was measured using the Fatigue Severity Scale (FSS; 9 items, 7 points each). Additionally, a closed-ended adherence survey captured participant perceptions of factors influencing adherence

• Study Type: Interventional
• Enrollment (Actual): 174
• Phase: Not Applicable

Contacts and Locations

Study Locations

• China
  • Beijing, China
    • Peking University Third Hospital Medicial Science Research Ethics Committee

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

• (1) Anterior knee pain or retro-patellar pain caused by at least two of the following activities: prolonged sitting with knee flexion, bilateral squatting, ascending and descending stairs, kneeling, running, and jumping;
• (2) presence of one of the following signs: patellar tenderness, friction pain, or twitching pain, positive single-leg squat test, or positive knee extension resistance test;
• (3) knee pain lasting more than 3 months;
• (4) knee pain score greater than 3 out of 10 on the VAS;
• (5) unilateral pain and symptoms.

Exclusion Criteria:

• (1) acute injury of the knee ligaments, joint capsule, bursa or meniscus;
• (2) knee extension or flexion contracture deformity, thus being unable to perform normal lower limb flexion and extension;
• (3) patellofemoral joint dislocation or subluxation;
• (4) any traumatic, inflammatory or infectious disease of the lower limbs;
• (5) a history of knee surgery;
• (6) a history of cardiovascular and cerebrovascular diseases, diabetes, tumors;
• (7) spinal cord or neurological injury.

Study Plan

How is the study designed?

Design Details

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

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Sham Comparator: one session of face-to-face telerehabilitation tutorial (OST); Participants were assigned to receive either one session of face-to-face telerehabilitation tutorial (OST) and complete an 8-week home digital health program consisting of sensor-guided exercise therapy and knee pain self-care education. The primary outcome was short-term adherence as assessed by the Exercise Adherence Rating Scale (EARS) after 6 weeks of face-to-face therapy. Secondary measures included pain intensity, quadriceps strength, Kujala patellofemoral score, fatigue severity scale, and qualitative interviews affecting adherence.	Device: one session of face-to-face telerehabilitation tutorial (OST); The first group participated in a face-to-face tele-rehabilitation session in the hospital on the use of sensors and rehabilitation software before the home-rehabilitation session. Thereafter, the tele-rehabilitation program included muscle strengthening, flexibility stretching, and movement quality training every Tuesday, Thursday, and Saturday.
Experimental: Three session of face-to-face telerehabilitation tutorials (TST); Participants were assigned to receive 3 in-person remote rehabilitation coaching (TST) sessions and complete an 8-week home digital health program consisting of sensor-guided exercise therapy and knee pain self-care education. The primary outcome was short-term adherence as assessed by the Exercise Adherence Rating Scale (EARS) after 6 weeks of face-to-face therapy. Secondary measures included pain intensity, quadriceps strength, Kujala patellofemoral score, fatigue severity scale, and qualitative interviews affecting adherence.	Device: Three session of face-to-face telerehabilitation tutorials (TST); The second group participated in three face-to-face tele-rehabilitation sessions in the hospital on the use of sensors and rehabilitation software before the home-rehabilitation session. Thereafter, the tele-rehabilitation program included muscle strengthening, flexibility stretching, and movement quality training every Tuesday, Thursday, and Saturday.
Experimental: Six session of face-to-face telerehabilitation tutorials (SST); Participants were assigned to receive 6 in-person remote rehabilitation coaching (SST) sessions and complete an 8-week home digital health program consisting of sensor-guided exercise therapy and knee pain self-care education. The primary outcome was short-term adherence as assessed by the Exercise Adherence Rating Scale (EARS) after 6 weeks of face-to-face therapy. Secondary measures included pain intensity, quadriceps strength, Kujala patellofemoral score, fatigue severity scale, and qualitative interviews affecting adherence.	Device: Six session of face-to-face telerehabilitation tutorials (SST); The third group participated in six face-to-face tele-rehabilitation sessions in the hospital on the use of sensors and rehabilitation software before the home-rehabilitation session. Thereafter, the tele-rehabilitation program included muscle strengthening, flexibility stretching, and movement quality training every Tuesday, Thursday, and Saturday.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
The primary outcome was device-recorded training adherence	The primary outcome was device-recorded training adherence, defined as cumulative total training time (hours) and mean weekly training time (hours/week) over the first 6 weeks of independent home-based telerehabilitation. Data recording commenced immediately after each participant completed his or her final face-to-face tutorial, thereby isolating adherence to the unsupervised home program. Because the three groups differed in the number of tutorials received, the calendar start date of the 6-week recording window varied: OST participants began the recording window after session 1; TST participants after session 3; and SST participants after session 6. The 6-week duration of the window was identical across groups.	Six weeks after completion of face-to-face rehabilitation instruction

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
pain intensity	Secondary outcome measures were collected at the hospital 8 weeks after the start of the study, including the severity of knee pain during daily living and squatting at 60 degrees (from 0 "no pain" to 10 "most severe") assessed on the visual analogue scale (VAS);	Complete the entire 8-week rehabilitation process
Self-reported adherence was measured using the Exercise Adherence Rating Scale	Self-reported adherence was measured using the Exercise Adherence Rating Scale (EARS) at week 6 (i.e., 6 weeks after the participant completed their final face-to-face tutorial). The EARS comprises Section A (6 items assessing adherence to prescribed home exercise) and Section B (10 items exploring barriers to adherence). Items are rated on a 5-point Likert scale (0 = "strongly disagree" to 4 = "strongly agree"), with positively phrased items reverse scored such that higher scores indicate better adherence. The EARS has demonstrated good reliability (Cronbach α = .85) and construct validity.	Six weeks after completion of face-to-face rehabilitation instruction
quadriceps strength	Isokinetic quadriceps femoris concentric and eccentric peak torque reflect muscle strength around the knee joint.The open-chain muscle strength of the quadriceps muscle was tested with an isokinetic muscle strength testing system (Contrex MJ) in two modes: 60°/s centripetal contraction and 60°/s centrifugal contraction. The range of the test was from 90° to 20° of knee flexion. During the test, the subjects were asked to relax as much as possible before the test, with the trunk flexed at an angle of 120°, so that the test could be performed under the reduced influence of gravity. Each contraction mode was repeated 5 times, and the interval between adjacent contraction modes was 3 minutes to rest the thigh muscles.	Complete the entire 8-week rehabilitation process
Kujala scores	Kujala patellofemoral score is used to evaluate the function of the knee joint (0-100, with higher scores indicating better knee function)	Complete the entire 8-week rehabilitation process
Fatigue severity scale	Fatigue severity scale (FSS) is used to measure the fatigue degree of patients with various diseases and its impact on people's activities and lifestyle (9 questions in total, 7 points for each question, the higher the score, the greater the fatigue degree)	Complete the entire 8-week rehabilitation process
adherence survey	Furthermore, the adherence survey collected structured responses through closed-ended questions on factors influencing telerehabilitation adherence. Response frequencies were calculated for each item	Complete the entire 8-week rehabilitation process

Collaborators and Investigators

• Sponsor: Peking University Third Hospital

Study record dates

Study Major Dates

• Study Start (Actual): January 1, 2025
• Primary Completion (Actual): May 31, 2025
• Study Completion (Actual): May 31, 2025

Study Registration Dates

• First Submitted: September 19, 2024
• First Submitted That Met QC Criteria: October 20, 2024
• First Posted (Actual): October 22, 2024

Study Record Updates

• Last Update Posted (Actual): May 28, 2026
• Last Update Submitted That Met QC Criteria: May 24, 2026
• Last Verified: May 1, 2025

More Information

Terms related to this study

• Keywords: mHealth; Telerehabilitation; Patellofemoral pain; Exercise adherence; Wearable sensors; Tutorial dose.
• Additional Relevant MeSH Terms: Musculoskeletal Diseases; Joint Diseases; Patellofemoral Pain Syndrome
• Other Study ID Numbers: M2023699

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No