Hospital-based Outpatient Physiotherapy Rehabilitation Versus Mobile Health (mHealth)-Based Exercise and Self-management in Patients With Symptomatic Knee Osteoarthritis

This provides a performance-based measure of physical function. Participants will walk at their usual pace (warm-up) and fast pace along a 4-metre walkway, with a 2.5-metre acceleration distance before and a 2.5-metre deceleration distance after the timed section. Gait timing will be captured concurrently using both a stopwatch and a time-of-flight sensor. Gait speed (m/s) will be calculated for both walking conditions; however, time-of-flight sensor-based fast-paced gait speed will be the primary outcome measure.

The ShortMAC-F is an OA-specific questionnaire designed to measure physical function.

Knee pain intensity will be measured using numeric pain rating scales (NPRS) that inquire about the average pain intensity level over the past 1 week.

Maximum quadriceps strength will be assessed on a seated knee extension machine using a standardized one repetition maximum (1RM) protocol.

This will be measured by the 5-times sit-to-stand test. Participants will perform the tests at their usual (warm-up) and fast pace, and their timing will be concurrently captured using both a stopwatch and a smartphone.

The EQ-5D-5L is a health-related quality of life instrument with established psychometric properties in Singaporeans. Quality-adjusted-life-years (QALY), derived from the EQ-5D-5L scores, will be the primary economic outcome and it will be used in the cost utility analysis.

Participants will rate their satisfaction with rehabilitation on a 11-point numeric rating scale, with 0 indicating "not at all satisfied " and 10 indicating "totally satisfied".

Participants will rate how likely they are to recommend this treatment to a friend or family member with knee arthritis using an 11-point numeric rating scale (allowing for 0.5 increments). A score of 0 indicates "Not at all likely," and a score of 10 indicates "Extremely likely."

GROC of overall change in pain and change in physical function since baseline will be measured using a 9-point ordinal scale, with 1 indicating "Much better" and 9 indicating "Much worse".

Participants will respond to the question "I do my knee strengthening exercises as often as recommended/advised," using a 0-10 scale (0 = strongly disagree, 10 = strongly agree).

Participants will report their knee strenghtening exercise frequency (days per week).

Between the baseline and the Month-6 assessment, we will use the modified OA Cost and Consequences Questionnaire (OCC-Q) to measure the use of other health and home care services, including hospitalizations, co interventions, visits to healthcare providers (e.g., doctors and other healthcare professionals), and prescribed or over-the counter medications. We will also collect information on participants' employment and income status and assess productivity losses, including restricted activity days (such as sick leave taken by participants and leave of absence taken by their caregivers).

The usability of the MOKneeTOR app will be measured using the System Usability Scale (SUS), which is a validated 10 item questionnaire that assesses perceived usability. Qualitative feedback from participants will be collected to help identify intervention elements that are perceived to be useful. Additionally, user engagement and usage metrics will be automatically captured by the system backend throughout the study.

Adverse events (AE) and serious adverse events (SAE) will be recorded at all follow-ups by asking the participants about potential AEs using open-probe questioning to ensure that all AEs are recorded.

This will be measured using a calibrated scale for body weight and bioelectrical impedance analysis (BIA) to assess body composition (e.g., fat mass, lean mass). As a proxy measure of overall muscle strength, handgrip strength of the dominant hand was measured using a Jamar Plus digital dynamometer. In the sitting position with the elbow flexed at 90degrees, each participant will perform three maximal trials with 30 s rest between trials, and the highest reading will be analyzed. These measures will help explore whether changes in body composition mediate improvements in physical function and pain.

Participants will respond to the question "Based on your knee symptoms in the past week, how willing would you be to have knee surgery if you were medically fit to do so?" using a 0-10 scale (0 = not at all willing, 10 = definitely willing). They will also respond to the question "How necessary do you think knee replacement surgery is for your condition?" using a 0-10 scale (0 = not at all necessary, 10 = totally necessary).

This will be measured by the pain subscale of Arthritis Self-Efficacy Scale, which measures a person's confidence in managing arthritis pain symptoms.

This will be measured using the Knee Osteoarthritis Knowledge Scale (KOAKS).

This will be measured by the Brief Fear of Movement Scale for Osteoarthritis.

This will be measured by the Four-Dimensional Symptom Questionnaire (4DSQ).

This will be assessed using the Multidimensional Scale of Perceived Social Support (MSPSS), a validated 12-item questionnaire designed to measure perceived social support from family. In addition to the MSPSS, we will use a study-specific.

Participants will report their planned walking activities using the walking subscale of the Incidental and Planned Exercise Questionnaire (IPEQ-W). They will indicate the frequency and duration of planned walking sessions over the past week. This measure captures structured walking exercise intended for health or fitness purposes, rather than incidental walking (e.g., walking for transport).

A long-arm goniometer will be used to measure active-assisted knee flexion and extension range-of-motion with the participants in supine position.

This assesses the ability of the participants to weight bear on both limbs. With their feet on 2 portable force plate, participants will stand up from a standard chair, and weightbearing symmetry is calculated by expressing the peak force produced by the involved leg as a percentage of that produced by the uninvolved leg.