The effect of plyometric training with blood flow restriction on muscle strength and function after anterior cruciate ligament reconstruction

The aim of this study was to investigate the effect of plyometric training with blood flow restriction (BFR) on muscle strength, muscle volume and function after anterior cruciate ligament reconstruction (ACLR). The study included 28 male patients aged 18-30 years who completed a 12-week rehabilitation program after ACLR. The patients were randomly allocated into two groups as BFR group (n=14, age: 19,64±2,16 year, BMİ: 23,55±2,69 kg/m2) and control group (n=14, age: 20,35±3,31 year, BMI: 22,5±3,02 kg/m2). Both groups received plyometric training for 8 weeks and 3 days a week in addition to the standard rehabilitation program. Plyometric training was performed with blood flow restriction only in BFR group. Quadriceps muscle thickness and rectus femoris cross-sectional area, hamstring and quadriceps muscle strength (isometric, concentric, eccentric), functional performances (vertical jump test, one leg hop test, 3 step hop test), dynamic balances (y balance test), knee functions (IKDC, KOOS, Tampa, ACL-RSI questionnaire) were evaluated before and after plyometric training. Rectus femoris, vastus medialis obliques, vastus lateralis muscle thickness, rectus femoris cross sectional area, isometric and concentric muscle strength of quadriceps and hamstring increased in both groups after training (p<0,05), whereas BFR group had higher increase in all parameters (p<0,05). The quadriceps and hamstring eccentric muscle strength results were similar, while quadriceps leg symmetry index improved in the BFR group (p=0,015). When the results of clinical tests and scales are examined; vertical jump test, y balance test, IKDC, Tampa, KOOS scores were improved in both groups (p <0,05), but this improvement was higher in BFR group (p <0,05). Single leg hop test symmetry index, triple hop test symmetry index and ACL-RSI scores were respectively better in BFR group (p=0,02, p=0,009, p= 0,03). As a result of our study, pliometric training with BFR was found to be more effective in increasing muscle strength, muscle volume and function in return to sports after ACLR. We think that plyometric training with BFR after anterior cruciate ligament injury is an alternative rehabilitation method that can be used during the return to sports.