Effectiveness of Wrist Extensor Strength Training With Blood Flow Restriction on Lateral Elbow Tendinopathy

Lateral epicondylitis is a work-related musculoskeletal disorder and is defined as persistent symptomatic degeneration of the wrist extensor muscle tendon that connects to the lateral humeral epicondyle. It is characterized by pain on the lateral side of the elbow joint, limited range of motion, and weakness in the forearm muscles.

Management of lateral epicondylitis is aimed at reducing pain and discomfort, preserving ROM, and enhancing the strength and endurance of the affected limb by using numerous techniques, including electrophysical methods and physical activity.

Blood flow restriction training (BFRT) involves partially restricting arterial blood flow into muscles while occluding venous outflow during exercise. It was first introduced into the literature in 1987 by researchers who used tourniquet ischemia to induce fatigue in muscles, dating back to Dr. Yoshiaki Sato in Japan, where it was known as "kaatsu training," meaning "training with added pressure." Kaatsu training is now performed worldwide and is more commonly referred to as "BFR training," which is achieved using a pneumatic tourniquet system.

In addition to physical rehabilitation, BFRT is used for physical training and performance in healthy individuals. There has been extensive research into its value as a training tool, including elite- and amateur-level athletes, untrained young and older adults, and hypertensive individuals.

In addition to reducing arterial blood flow to working muscles, blood flow restriction obstructs venous return. When active muscles are exposed to BFR conditions, they are subjected to ischemia, which increases the metabolic stress on them. In addition to BFR, venous occlusion increases muscle cell swelling, activates intracellular anabolic pathways, and recruits fast-twitch fibers, which are thought to be involved in muscle adaptation.

There were different Factors affecting exercise adaptations with BFR, including pressure of occlusion (partial or complete), type of occlusion (continuous or intermittent), intensity of exercise, and volume of

Exercise with BFR:

BFR, along with low-load resistance training, cardio endurance training, and other activities that are generally recommended to improve muscular mass/strength, is also associated with these adaptations in muscles.

The randomized trial done by Karanasios et al to assess the effect of low-load resistance training with blood flow restriction (LLRT-BFR) versus LLRT with sham-BFR in patients with lateral elbow tendinopathy (LET) found that LLRT with blood flow restriction produced significantly better pain, strength, and function improvement in comparison to LLRT with sham-BFR for all primary outcomes(Karanasios et al., 2022).

Regarding the study of proximal and distal effects of BFR Training, a study by Bowman et al. on Lower extremity Low-load BFR training resulted in greater increases in muscle strength and limb circumference in healthy participants after completing a standardized 6-week course of BFR training. Muscle groups at the proximal and distal ends of the body were similarly strengthened after BFR training(Bowman et al., 2019).

This study aims to explore the effects of incorporating BFR into wrist extensor strength training for athletes with lateral epicondylitis. By evaluating its impact on strength, function, pain, range of motion (ROM), and overall quality of life, this research seeks to determine whether BFR can optimize rehabilitation outcomes and provide a more effective treatment strategy for LET.

Inclusion criteria

• Both Male and female, aged between 18 to 45 years old.
• Subjects with a positive test of lateral epicondylitis, which will be determined based on physical therapy assessment procedures.
• The presence of tenderness over the lateral epicondyle.positive Cozen's and Mill's tests.
• Pain on grasping.
• Pain on passive flexion of the wrist with elbow extension.
• Pain with resisted wrist extension.
• Show decreased muscle strength and functional ability.

Exclusion criteria

• Patients with shoulder tendinopathy, cervical radiculopathy, and rheumatoid arthritis.
• Presences of sensory and motor impairment of the upper extremities
• History of cardiovascular disease
• History of trauma and surgery on the elbow
• Having a history of malignancy and peripheral vascular disorders.