P4ACE Trial for Persons With Chronic Knee Pain

The goal of this double-blind, cross-over clinical trial is to compare the immediate effect of intermittent vs. continuous walking on clinical and mechanistic pain profiles in persons with knee osteoarthritis (OA). In this cross-over trial, participants will perform two types of walking on a treadmill. Intermittent walking will involve 3 blocks of 10 minutes with 2 blocks of 5-minute rest (sitting on a chair) in-between. Continuous walking will involve resting for 10 minutes (sitting in a chair) before walking on the treadmill for 1 continuous block of 30 minutes.

Inclusion Criteria:men or women aged 45-75 yearsBMI ≤ 35 kg/m2frequent movement-related knee pain (knee pain on more than half the days of the past month)no morning stiffness or morning stiffness lasting < 30-minself-reported unilateral or bilateral knee pain of ≥ 3 and ≤ 7 on a 0-10 numeric pain rating scale (NPRS)knee pain duration ≥ 12 monthsphysically able to walk unassisted on a treadmill at ≥ 4 km/hour for 30 minutesown a smart phonewilling and able to wear an activity monitor and answer electronic survey questions delivered via a smart phone over a 10-day period.Exclusion Criteria:intra-articular steroid injections in the previous 3 monthsintra-articular hyaluronic acid injection in the previous 6 monthsany arthroscopic or surgical knee procedures (e.g., partial meniscectomy) in the past 12 monthslumbar radiculopathyneurological, vestibular, or visual dysfunction affecting walking balance and mobilityplan for total knee arthroplasty in the next 12 months