Overview
This randomized controlled trial compares blood flow restriction (BFR) resistance training (leg press and seated knee extension at 30% 1RM) versus BFR cycling (stationary cycling at low resistance) in 60 athletes (aged 18-40 years) diagnosed with patellofemoral pain syndrome. Both interventions are delivered over 8 weeks (3 sessions/week) with a pneumatic cuff set at 80% limb occlusion pressure. Primary outcomes include pain intensity (NPRS), quadriceps strength (handheld dynamometer), and functional ability (Kujala Anterior Knee Pain Scale), assessed at baseline and post-intervention.
Description
Patellofemoral pain (PFP) is among the most prevalent musculoskeletal conditions in athletes, with reported prevalence of 30-40% in sports populations. High-load resistance training is the conventional rehabilitation approach but often exacerbates joint stress and reduces adherence. Blood flow restriction (BFR) training enables strength gains at low loads by applying a pneumatic cuff at 80% LOP on the proximal thigh.
This trial compares two BFR modalities:
- Group A (BFR-RT): Leg press and seated knee extension, 1x30 + 3x15 reps at 30% 1RM, 3x/week for 8 weeks.
- Group B (BFR-CYC): Stationary cycling at low resistance, 4x5-minute intervals at 70-80 RPM (RPE 11-13), 3x/week for 8 weeks.
All sessions are supervised one-on-one by a physiotherapist. Assessments are conducted at baseline and week 8. The study is single-blinded (outcome assessor blinded). Randomization via computer-generated sequence. Statistical analysis via SPSS v27 (paired t-test / Wilcoxon for within-group; independent t-test / Mann-Whitney for between-group, alpha=0.05).
Eligibility
Inclusion Criteria:
- Male and female athletes aged 18-40 years
- Clinically diagnosed with patellofemoral pain syndrome
- Anterior or retropatellar knee pain of at least 3 months duration
- Pain provoked by at least two functional activities (e.g., squatting, stair climbing, running, prolonged sitting)
- Willingness to participate and provide written informed consent
Exclusion Criteria:
- History of knee surgery or significant knee trauma in the past 6 months
- Presence of ligament, meniscal, or cartilage injuries
- Neurological, vascular, or systemic inflammatory conditions
- Contraindications to BFR training (e.g., deep vein thrombosis, uncontrolled hypertension)
- Pregnancy
