**3.1. Flow of participants through the study**

A total of 75 participants that were admitted with bilateral knee OA between February and March 2016 were screened for inclusion. Fifteen patients were excluded based on the eligibility criteria. Therefore, the study reports the data of 60 participants. All of them agreed to participate and they were subsequently randomized: 30 in the experimental group (US) and 30 in the control group (ESWT), as presented in **Figure 1**. The baseline characteristics of participants are shown in **Table 1** and in the first two columns of data in **Table 2** and **Table 3**. No important differences in these characteristics were noted between the experimental and control groups.
