**2.2. Participants and center**

the patients with OA have almost the same symptoms, including pain, stiffness, articular instability, limitation of motion and physical activity, and muscle weakness [1, 2]. Physiotherapy is one of the treatments that provides effective nonpharmacological interventions for people with knee OA, and procedures prescribed by physiotherapists are considered to be important and to play a fundamental role in patients' treatment. The most common types of electrotherapy are ultrasound (US), transcutaneous electrical nerve stimulation (TENS), and now more often appearing extracorporeal shock wave therapy (ESWT). US, as a noninvasive treatment is used to create a controlled, microtrauma to local affected tissue in order to stimulate a healing response and microvascularization [3, 4]. The first use of ESWT was not for musculoskeletal disorders but to break up kidney stones. It was a coincident that someone noticed an osteoblastic response pattern during studies at animals in the 1980s [5]. Recently, ESWT has been used for pain relief and musculoskeletal disorders' treatment. It turned out that ESWT is also a noninvasive treatment, and the effectiveness of this method is comparable to surgery. It has not yet been fully explained how it exactly works, but it probably involves microdestructions—the application of ESWT causes microbreaks in avascular or poorly vascularized tissue, thus stimulating appropriate revascularization and stem cell growth. It also induces the release of enzymes, which affect nociceptors, resulting in localized analgesia, giving the

significant reduction of activity limitations and short duration of the treatment [6].

pain, and improving perceived health in men suffering from bilateral knee OA.

Therefore the research question was

264 Pain Relief - From Analgesics to Alternative Therapies

OA?

**2. Method**

**2.1. Design**

Despite the advances in the treatment, there is lack of comparative studies on the effects of US and ESWT in patients with knee OA. Therefore, the purpose of this study was to evaluate the effects of US versus ESWT protocol on pain measured by visual analogue scale (VAS), and on perceived health measured by WOMAC [7, 8] in men suffering from bilateral knee OA.

In our study we took hypothesis: there are differences between US and ESWT in reducing of

**1.** Is US more effective than ESWT on pain and perceived health in men with bilateral knee

It was a randomized trial with concealed allocation, assessor blinding, and intention-to-treat analysis. The participants with knee OA were assessed for eligibility by an independent physician who was not involved into the study. The randomization into an experimental group (US) and a control group (ESWT) with a 1:1 ratio was generated by permuted block randomization using the website www.random.org. The randomization was achieved by having the participant selected one from 60 sealed opaque envelopes, each containing a group allocation, which had been prepared and shuffled by an independent investigator who was not involved into the recruitment or assessment of the participants. The researchers responsible for assessing the outcomes and analyzing the data were blinded to the type of the treatment procedure. The inclusion criteria for participation in the study were: minimum age of 40, not currently receiving any physical therapy treatments for the knee OA condition, medication compliance (all patients were taking glucocorticoids at the time of the study), and the diagnosis of bilateral knee OA according to the American College of Rheumatology criteria [9].

The exclusion criteria were: any rheumatic disease (with the exception of bilateral knee OA), unilateral knee OA, skin changes, neurological disorders, mental illness, cancer, endocrinology disease, or previous knee surgery.

The evaluations of this study were conducted at the Physiotherapy Outpatient Department of the Regional Hospital in Zywiec, Poland. This study was designed with respect for the rules of conducting experimental studies with humans after the approval by the Bioethical Committee at the Holycross College in Kielce, and were consistent with the Helsinki Declaration of 1975 as revised in 2000. All participants signed consent forms knowingly participation in the study.
