Validity and Reliability of Smartphone Use in Measuring Joint Position Sense in Patients With Knee Osteoarthritis

Knee repositioning error will be measured simultaneously by smartphone and Biodex isokinetic dynamometer by a single blind assessor. All assessments will be done with eyes closed and repeated over two separate sessions, with one-week interval in-between. For active repositioning, the participant will actively extend the knee to reach a predetermined target position45° flexion at an angular velocity of 10°/sec. For passive knee repositioning, the isokinetic dynamometer will move the knee at 5°/s to a predetermined angle between 5° and 80° of flexion and the participant should stop the movement when the predetermined angle is reached.