Lateral epicondylitis (LE) is a common musculoskeletal disorder caused by repetitive overuse of the forearm extensor muscles. It is characterized by pain over the lateral epicondyle of the humerus, which may radiate to the surrounding tissues at the origin of the wrist extensor tendons. LE is one of the most frequent causes of lateral elbow pain, with a reported prevalence of approximately 1-3% in the general population. Among conservative interventions, exercise-based rehabilitation is considered a cornerstone of management. In particular, exercise programs incorporating eccentric contractions have demonstrated superior clinical outcomes compared with several other exercise approaches and are therefore widely recommended. Blood flow restriction training (BFRT) has recently emerged as an alternative rehabilitation strategy that promotes neuromuscular adaptations while using low mechanical loads. BFRT involves the application of a pneumatic cuff, tourniquet, or elastic band around the proximal portion of an extremity to partially restrict arterial inflow while substantially reducing venous return, thereby creating localized metabolic and hemodynamic stress during exercise. The primary aim of this randomized controlled trial was to investigate the effects of BFRT on pain, functional status, pain-free grip strength, health-related quality of life, and ultrasonographic characteristics of the common extensor tendon in patients with lateral epicondylitis.
Lateral epicondylitis (LE) is a common musculoskeletal disorder caused by repetitive overuse of the forearm extensor muscles. It is characterized by pain over the lateral epicondyle of the humerus, which may radiate to the surrounding tissues at the origin of the wrist extensor tendons. LE is one of the most frequent causes of lateral elbow pain, with a reported prevalence of approximately 1-3% in the general population. Although numerous conservative and invasive treatment modalities have been described, no universally accepted treatment algorithm currently exists. Among conservative interventions, exercise-based rehabilitation is considered a cornerstone of management because it improves tendon load tolerance, increases muscle strength, and facilitates functional recovery. Although no consensus has been reached regarding the optimal exercise protocol, recent research has focused on interventions that enhance the adaptation of the common extensor tendon to mechanical loading. In particular, exercise programs incorporating eccentric contractions have demonstrated superior clinical outcomes compared with several other exercise approaches and are therefore widely recommended. Furthermore, regular exercise has been shown to improve tendon mechanical properties by increasing collagen synthesis as well as collagen fiber number and diameter. To achieve meaningful improvements in muscle strength and hypertrophy, resistance exercise is generally recommended at loads of at least 70% of the one-repetition maximum (1RM). However, such loading is often poorly tolerated by individuals experiencing pain, muscle weakness, or muscle atrophy during the early stages of musculoskeletal rehabilitation. Consequently, high-intensity resistance exercise may exacerbate symptoms and reduce treatment adherence. Blood flow restriction training (BFRT) has recently emerged as an alternative rehabilitation strategy that promotes neuromuscular adaptations while using low mechanical loads. BFRT involves the application of a pneumatic cuff, tourniquet, or elastic band around the proximal portion of an extremity to partially restrict arterial inflow while substantially reducing venous return, thereby creating localized metabolic and hemodynamic stress during exercise. In BFRT, resistance exercises are typically performed at 20-30% of the one-repetition maximum (1RM). Despite the low training intensity, accumulating evidence indicates that BFRT can produce gains in muscle strength and hypertrophy comparable to those achieved with conventional high-intensity resistance training. These characteristics make BFRT an attractive adjunct or alternative to traditional resistance exercise in musculoskeletal rehabilitation, particularly for minimizing excessive tissue loading during tendon healing, preventing muscle atrophy, and preserving functional capacity. Nevertheless, evidence regarding the effects of BFRT on clinical outcomes and tendon morphology in patients with lateral epicondylitis remains limited. The primary aim of this randomized controlled trial was to investigate the effects of BFRT on pain, functional status, pain-free grip strength, health-related quality of life, and ultrasonographic characteristics of the common extensor tendon in patients with lateral epicondylitis. A secondary aim was to compare these outcomes with those achieved using a conventional exercise program and to determine whether BFRT induces measurable structural changes in tendon morphology as assessed by ultrasonography.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
SINGLE
Enrollment
60
Both groups participated in a supervised exercise program consisting of 12 sessions over four weeks (three sessions per week), with each session lasting approximately 45 minutes. Each treatment session began with 3-5 minutes of transverse friction massage applied to the painful region, followed by gentle circular soft-tissue mobilization in a proximal-to-distal direction. Resistance exercises were then performed using dumbbells and consisted of concentric and eccentric wrist extension and forearm supination exercises. The order of exercises was standardized for all participants throughout the intervention period. Participants allocated to the BFRT group performed the exercise program under blood flow restriction using a pneumatic cuff positioned around the proximal portion of the affected upper arm. Before the intervention, arterial occlusion pressure (AOP) was individually determined for each participant. The cuff pressure used during training was set at 50% of the individual AOP. Tot
Participants in the control group performed the identical exercise protocol without blood flow restriction.
Necmettin Erbakan University, Faculty of Medicine, Department of Physical Medicine and Rehabilitation
Konya, Turkey (Türkiye)
Patient-Rated Tennis Elbow Evaluation (PRTEE)
The Patient-Rated Tennis Elbow Evaluation (PRTEE) is a disease-specific, patient-reported outcome measure designed to assess pain and functional disability associated with lateral epicondylitis (14,15). The questionnaire consists of two domains evaluating pain and functional limitations, with a total score ranging from 0 to 100, where higher scores indicate greater pain and disability. The Turkish version of the PRTEE has demonstrated satisfactory validity and reliability
Time frame: Baseline, at 4 weeks (end of intervention), and at 12 weeks (follow-up).
Visual Analog Scale (VAS)
Pain intensity at rest and during activity was assessed using a 10-cm Visual Analog Scale (VAS). The scale ranges from 0 ("no pain") to 10 ("worst imaginable pain"). Participants were instructed to indicate the intensity of their pain by marking a point on the scale corresponding to their perceived pain level. The score was determined by measuring the distance (cm) from the left endpoint to the participant's mark. The VAS is a valid and reliable instrument for assessing pain intensity in patients with musculoskeletal disorders.
Time frame: Baseline, at 4 weeks (end of intervention), and at 12 weeks (follow-up).
Pain-free grip strength (PFGS) Assessment
PFGS is considered a sensitive indicator of functional impairment in patients with lateral epicondylitis. Participants were seated with the shoulder in a neutral position, the elbow comfortably extended, and the forearm pronated. Firstly, maximal grip strength was measured using a Jamar hydraulic hand dynamometer in kilograms on the unaffected side. Participants were then instructed to gradually squeeze the dynamometer with the affected hand and stop immediately when pain was first perceived. Three measurements were obtained for each assessment with a 20-second rest interval between trials, and the mean value was used for analysis. PFGS was calculated as the ratio of pain-free grip strength of the affected side to maximal grip strength of the unaffected side. This method has been shown to provide excellent reliability in individuals with lateral epicondylitis.
Time frame: Baseline, at 4 weeks (end of intervention), and at 12 weeks (follow-up).
Health-Related Quality of Life
Health-related quality of life was evaluated using the 36-Item Short Form Health Survey (SF-36). The SF-36 comprises eight domains: physical functioning, role limitations due to physical health, bodily pain, general health perceptions, vitality, social functioning, role limitations due to emotional problems, and mental health. Each domain is scored from 0 to 100, with higher scores indicating better health-related quality of life. The Turkish version of the SF-36 has been validated and shown to be reliable
Time frame: Baseline, at 4 weeks (end of intervention), and at 12 weeks (follow-up).
Ultrasonographic Evaluation of the Common Extensor Tendon
Ultrasonographic examinations were performed using a 7-12 MHz linear-array transducer (Logiq P8; GE Healthcare, Wisconsin, USA). The measurements were taken by a researcher with four years of experience in musculoskeletal ultrasound who did not know which group the patients belonged to. Participants were examined in a seated position with the elbow flexed to 90° and the forearm pronated. Longitudinal images of the common extensor tendon were obtained, and tendon thickness perpendicular to the tendon fibers, was measured at two standardized anatomical landmarks: (1) the deepest point over the capitellum and (2) the midpoint of the radiocapitellar joint. To improve measurement reliability, each measurement was repeated three times, and the mean value was used for statistical analyses.
Time frame: Baseline, at 4 weeks (end of intervention), and at 12 weeks (follow-up).
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