Blood Flow Restriction Training in Tennis Elbow (tennis elbow)

Effects of Blood Flow Restriction Training on Pain, Function, Disability, Quality of Life, and Common Extensor Tendon Thickness and Echogenicity in Patients With Lateral Epicondylitis: A Prospective Randomized Controlled Trial

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.

Study Overview

• Status: Completed
• Conditions: Tennis Elbow Syndrome
• Intervention / Treatment: Procedure: Blood Flow Restriction Training; Procedure: Exercise without blood flow restriction

Detailed Description

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
• Enrollment (Actual): 60
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Turkey (Türkiye)
  • Konya, Turkey (Türkiye)
    • Necmettin Erbakan University, Faculty of Medicine, Department of Physical Medicine and Rehabilitation

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• age between 18 and 75 years;
• clinical diagnosis of lateral epicondylitis based on medical history and physical examination;
• pain intensity of ≥4 on a 10-cm Visual Analog Scale (VAS) during daily activities;
• provision of written informed consent.

Exclusion Criteria:

• hypertension, diabetes mellitus, cardiovascular disease, peripheral vascular disease, previous deep vein thrombosis, or lymphedema;
• orthopedic, rheumatologic, or neurological disorders affecting the upper extremity;
• fibromyalgia;
• congenital or acquired elbow deformity;
• previous trauma, fracture, or surgery involving the affected upper extremity;
• cervical radiculopathy or peripheral neuropathy affecting the involved limb;
• receipt of any treatment for lateral epicondylitis within the preceding 3 months;
• skin lesions, infection, or open wounds at the cuff application site;
• bleeding disorders or current anticoagulant therapy;
• pregnancy;
• active malignancy or a history of malignancy;
• cognitive impairment or neurological or psychiatric disorders that could interfere with comprehension of study procedures or completion of outcome assessments.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Control group	Procedure: Exercise without blood flow restriction; Participants in the control group performed the identical exercise protocol without blood flow restriction.
Experimental: Blood flow restriction training (BFRT) group	Procedure: Blood Flow Restriction Training; 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

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
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	Baseline, at 4 weeks (end of intervention), and at 12 weeks (follow-up).

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
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.	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.	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	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.	Baseline, at 4 weeks (end of intervention), and at 12 weeks (follow-up).

Collaborators and Investigators

• Sponsor: Necmettin Erbakan University

Study record dates

Study Major Dates

• Study Start (Actual): February 28, 2025
• Primary Completion (Actual): February 28, 2026
• Study Completion (Actual): February 28, 2026

Study Registration Dates

• First Submitted: July 14, 2026
• First Submitted That Met QC Criteria: July 14, 2026
• First Posted (Actual): July 17, 2026

Study Record Updates

• Last Update Posted (Actual): July 17, 2026
• Last Update Submitted That Met QC Criteria: July 14, 2026
• Last Verified: May 1, 2025

More Information

Terms related to this study

• Keywords: rehabilitation; quality of life; blood flow restriction training; ultrasonography; grip strength; Tennis elbow
• Additional Relevant MeSH Terms: Elbow Tendinopathy; Elbow Injuries; Musculoskeletal Diseases; Muscular Diseases; Wounds and Injuries; Tendon Injuries; Arm Injuries; Tendinopathy; Tennis Elbow; Motor Activity; Movement; Musculoskeletal Physiological Phenomena; Musculoskeletal and Neural Physiological Phenomena; Therapeutics; Physical Therapy Modalities; Patient Care; Exercise Therapy; Rehabilitation; Aftercare; Continuity of Patient Care; Exercise; Blood Flow Restriction Therapy
• Other Study ID Numbers: 2025/5793

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: All collected IPD, all IPD that underlie results in a publication
• IPD Sharing Time Frame: Starting 6 months after publication- ending 2 years after the publication of results
• IPD Sharing Access Criteria: Journal editors or reviewers may request this information from the corresponding author's email address if they deem it necessary.
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP; ICF; ANALYTIC_CODE; CSR

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No