Inclusion and exclusion criteria
Patients of both genders aged 40–80 years referred for physical therapy treatment at the UNICID clinic with knee pain intensity ≥2 on the pain Numerical Rating Scale (NRS)22 and radiographic examinations showing knee OA grades II, III or IV according to the classification
of Kelgren and Lawrence23 24 were eligible for the study.24 All patients had knee OA according to American College of Rheumatology criteria.25 The exclusion criteria were the inability to walk, a history of cancer, neurological deficits (sensory or motor),cardiac pacemaker, metal prostheses, type I diabetes,uncontrolled systemic arterial hypertension, morbid obesity or the use of antidepressants, tranquillisers or anti-inflammatory steroids in the last 3 months;
patients who were undergoing physical therapy sessions and using analgesics on the day of the treatment were also excluded.