A Comparison of the Effects of Combining ESWT With Blood Flow Restriction Therapy in Patients Diagnosed With Lateral Epicondylitis: a Randomized Controlled Trial

Overview

Lateral epicondylitis is a chronic degenerative tendinopathy characterized by pain, tenderness, decreased grip strength, and functional limitations, particularly on the outer part of the elbow. While conservative treatments such as nonsteroidal anti-inflammatory drugs (NSAIDs), physical therapy, and extracorporeal shock wave therapy (ESWT) are used, surgical methods are considered as alternatives in resistant cases. ESWT reduces pain and inflammation by increasing vascularization in the targeted area and supporting tissue regeneration. Blood flow restriction therapy (BFR), on the other hand, promotes muscle hypertrophy and strength gains through low-intensity exercise. The biochemical effects of both methods increase cellular proliferation and protein synthesis through different mechanisms, thereby supporting tissue healing and functional recovery. However, there are no studies in the literature examining the effects of combining ESWT and BFR in patients with lateral epicondylitis. Therefore, in our study, we aimed to evaluate the effects of the combined application of ESWT and BFR on pain, muscle strength, and functionality in the treatment of lateral epicondylitis. Patients will be divided into two groups and will undergo treatment for a total of 4 weeks, with one session per week. The study group will receive ESWT treatment in combination with blood flow restriction therapy (BFR). The control group will receive only ESWT. In both groups, the intensity of the ESWT treatment will be increased between sessions based on the patient's pain tolerance. Pain levels, grip strength, wrist isometric muscle strength, and upper extremity functional status will be assessed in patients in both the treatment and control groups before and after treatment. The effectiveness of the methods will be statistically analyzed. The findings obtained may contribute to the development of an innovative, evidence-based treatment protocol in the field of physical therapy and rehabilitation, thereby filling a gap in the literature aimed at improving pain management and functional recovery in the treatment of lateral epicondylitis.

Lateral epicondylitis is a form of tendinitis characterized by pain at the attachment site of the common extensor tendons of the wrist to the lateral epicondyle, resulting from inflammation and degeneration (Kraushaar \& Nirschl, 1999). It is most commonly seen in individuals aged 40-59, with a prevalence of 1.3% (Zhang et al., 2024). Common risk factors include female gender, obesity, a history of smoking, repetitive activities, and ipsilateral rotator cuff dysfunction (Shiri et al., 2006). Typically, pain on the lateral aspect of the elbow and forearm, restricted range of motion in the elbow and wrist joints, decreased muscle strength, and loss of function may be observed due to repetitive forearm supination/pronation and wrist extension (Shiri \& Viikari-Juntura, 2011; G et al., 2024). Treatment options include medical (oral and topical nonsteroidal anti-inflammatory drugs, local corticosteroid injections), conservative (cryotherapy, orthoses, electrotherapy, etc.), and surgical methods. Among conservative methods, Extracorporeal Shock Wave Therapy (ESWT) is frequently preferred (Lai et al., 2018). ESWT is a non-invasive method that utilizes high-frequency acoustic waves for therapeutic purposes in target tissues. This method supports tissue regeneration by enhancing angiogenesis at the tendon-bone junction through the stimulation of vascular endothelial growth factors and nitric oxide synthesis, and reduces pain by inhibiting pain receptors (Yoon et al., 2020). Additionally, it triggers the release of lubricin, which facilitates tendon repair and gliding by stimulating tenocyte proliferation through increased expression of TGFβ1 and IGF-1 (Zhang et al., 2011). The literature has demonstrated that ESWT has effects on lateral epicondylitis, such as alleviating pain, shortening recovery time, increasing grip strength, and enabling patients to return to their daily activities (Murat et al., 2024; Pettrone \& McCall, 2005). Another conservative method used in the treatment of lateral epicondylitis is Blood Flow Restriction Therapy (BFR). In this method, arterial blood flow is partially restricted and venous return is blocked by applying an external device (tourniquet or adjustable-pressure cuff) to the proximal part of the extremity (Patterson et al., 2019). This causes the targeted muscle group to work in an ischemic, hypoxic environment, triggering a significant increase in muscle mass and strength by activating fast-twitch muscle fibers (Gorgey et al., 2016; Scott et al., 2014). Studies investigating the effects of BFR on lateral epicondylitis have shown that it reduces pain, increases grip strength, and contributes to functional improvement (Karanasios et al., 2022; Kinandana et al., 2023). In the literature, the effects of both methods on lateral epicondylitis have been examined separately, but their efficacy has not been compared. Therefore, the aim of our study is to compare the efficacy of extracorporeal shock wave therapy (ESWT) and blood flow restriction therapy (BFR) in patients with lateral epicondylitis. By comparing different treatment methods that can be used in the management of lateral epicondylitis symptoms, our study will contribute to the use of more personalized and effective treatment strategies by healthcare professionals and will serve as a guide for future research.