25 patient, in which 41 knees presented with patellofemoral syndrome and patellar chondropathy, were randomized to either nine sessions of pulsed signal therapy or sham intervention. Patients were followed-up after 3 months for outcome on the Kujala score. At the 3 month follow-up, patients originally assigned to sham intervention crossed over to active treatment with pulsed signal therapy. At the 3-month follow-up, the improvement on the Kujala scoring questionnaire was significantly greater in those administered pulsed signal therapy compared to those administered sham therapy.