Inclusion Criteria:  aged from 50 and 75; symptomatic knee osteoarthritis for at least three months; visual analogue scale12 score above 3 and radiographic knee osteoarthritis (uni or bilateral) compatible with Kellgren-Lawrence13 grade two or higher.  Exclusion Criteria:  contraindication to laser application (e.g. cancer and insulin-dependent diabetes); inability to perform the assessment or treatment; continuous use of anti-inflammatory drugs, symptomatic hip osteoarthritis physiotherapeutic knee treatment within the last 3 months.