Primary outcomes were average knee pain ( numeric rating scale , @ -LSB- no pain -RSB- to @ -LSB- worst pain possible -RSB- ; minimal clinically important difference -LSB- MCID -RSB- , @ units ) and physical function ( Western Ontario and McMaster Universities Osteoarthritis Index , @ -LSB- no difficulty -RSB- to @ -LSB- extreme difficulty -RSB- ; MCID , @ units ) at @ weeks .