The Acute Effects of Static and PNF Stretching Exercise With Blood Flow Restriction in Athletes

The Acute Effects of Static and PNF Stretching Exercise With Blood Flow Restriction on Hamstring Flexibility, Muscle Strength and Single Leg Hop in Athletes : A Randomized Controlled Trial

The study aims to examine the acute effects of static and proprioceptive neuromuscular facilitation stretching exercises with blood flow restriction on hamstring flexibility, muscle strength, and single leg hop in athletes. Outcome measures were hip range of motion, isometric and eccentric hamstring muscle strength, and single leg hop distance.

A total of 109 athletes were included in the study. Participants were randomized into five groups: (1) static stretching, (2) proprioceptive neuromuscular facilitation (PNF) stretching, (3) blood flow restriction (BFR) + static stretching, (4) BFR + PNF stretching, and (5) control groups. Stretching exercises were performed on the dominant leg hamstring muscle group for 3 sets of 15 seconds each. BFR was applied during the stretching to the blood flow restriction (BFR) + static stretching and BFR + PNF stretching groups. No stretching was applied to the control group.

Assessments were performed at baseline and immediately after stretching. Hamstring flexibility (hip joint range of motion) was assessed via the passive straight leg raise test. Isometric and eccentric hamstring muscle strength were measured using a hand-held dynamometer, and muscle power was assessed using the single leg hop distance.

Inclusion Criteria:

• Age between 18-40 years old
• Engaged in regular physical activity for at least 8 hours a week for the last 6 months
• Body mass index (BMI) < than 30 kg/m²
• Momentary blood pressure less than 135/85 mmHg

Exclusion Criteria:

• History of fractures or surgical operations involving the lower limbs, hips, or lumbar region
• history of fractures, surgeries and other diagnosed medical conditions on the lower extremity, hip, and lumbar region
• Systemic musculoskeletal disease
• Pain in the lower back, hips, or lower extremities
• Known hip deformity or diagnosis of scoliosis
• History of deep vein thrombosis or embolism
• Diagnosis of circulatory system diseases such as hypertension or peripheral vascular disease
• History of anemia
• Previous cerebrovascular disease or myocardial infarction.