| Objective: To investigate the short-term efficacy of blood flow restriction training (BFRT) versus conventional resistance training for the recovery of quadriceps morphology and isokinetic knee extension strength, and to explore potential sex-related differences in the efficacy of BFRT. Methods: A total of 50 patients who had under-gone knee arthroscopy were randomly allocated to a control group (n=25) or a BFRT group (n=25). Both groups followed an identical standard rehabilitation program that included lower-limb strength training on a leg-press device for 4 weeks. The BFRT group performed the leg-press exercises with blood-flow restriction. Outcomes were assessed before and 4 weeks after treatment. Musculoskeletal ultrasound was used to measure the thickness of the rectus femoris, cross-sectional area (CSA) of the rectus femoris, and thickness of the vastus intermedius of the operative limb. An isokinetic dynamometer was used to record peak knee-extension torque normalized to body weight, and a tape measure was used to determine mid-thigh circumference 10 cm above the superior pole of the patella. Results: After 4 weeks, the BFRT group showed significant post-treatment increases in rectus femoris thickness, rectus femoris CSA, and vastus intermedius thickness (all P<0.01). Both groups exhibited significant increases in peak knee-extension torque normalized to body weight (P<0.01), with no statistically significant difference between the two groups in this outcome. A significant interaction effect between training modality and sex was observed for changes in peak knee-extension torque normalized to body weight (P<0.01). Mid-thigh circumference (10 cm above the superior pole of the patella) also increased significantly in the BFRT group (P<0.01). Conclusion: Both BFRT and conventional strength training improved the peak knee-extension torque-to-body weight ratio after knee arthroscopy. BFRT demonstrated superior effects on muscle strength in female participants compared with male participants. Furthermore, BFRT improved ultrasound-assessed quadriceps morphology and increased muscle circumference. |
