A latest clinical trial published in the 'Arthritis & Rheumatology', portrayed that the lateral wedge insoles reduced knee pain in people pre-screened to eliminate those with patellofemoral osteoarthritis (OA) and biomechanical non‐responders. But, the effect of treatment was small and is most likely of clinical significance in only some patients.

The lateral wedge shoe insoles decrease medial knee loading, although trials have shown no effect on pain relief in medial knee OA. The insoles' loading effects are inconsistent, and they can lead to patellofemoral loading. David T. Felson and researchers hypothesized that insoles would reduce pain in preselected patients. The patients with patellofemoral OA and those with pain <4/10 were excluded in people suffering from painful medial knee OA. The participants in a gait laboratory using lateral wedges, who did not have at least a 2% reduction in knee adduction moment (KAM) compared with their shoes and a neutral insole were also excluded. The subjects were randomized to lateral wedge versus neutral insole for 8 week period separated by an 8-week washout. The primary outcome encompassed knee pain over the past week (0‐10) and secondary outcomes considered the activity pain and KOOS pain. Mixed model analyses were performed for baseline pain. Twenty-one (25%) were excluded due to an insufficient reduction in KAM out of a total of 83 participants. The mean age of these 62 participants was 64.2 years (SD 9.1) out of which 37.1% were women. A more significant reduction in knee pain was observed in lateral wedge insoles as compared to the neutral insoles. The secondary outcomes had mixed findings.

The study authors suggested that targeting the patients may recognise those who respond to the treatment using the lateral wedge insoles.