PICO
Patient/Population
Patients with ACL rupture and reconstructive surgery (n=18)
Intervention
- Blood Flow Restriction (BFR)
Comparison
- SHAM-BFR
- Control (muscle biopsies)
Outcomes
- Isokinetic strength of quadriceps and hamstring muscles
- Muscle size changes
- Total work performed during exercises
- Volume per session progress
- Muscle hypertrophy and gains in muscle performance
- HIF1A; HIF2A; VEGFA; PGK1; IL6; IL6; IL6ST; MSTJN; ACVR2B; OSTN
Translatability: (3/3) Easy
Comments: ” …Results show augmented strength and endurance of knee extensors but less of the flexors. LL-BFR training is especially effective for conditioning of knee extensors in this population.”
Limitations: Inability to match groups for all baseline patient characteristics. Lack of assessment of changes in joint pain intensity and location. Potential interference of joint pain with arthrogenic muscle inhibition and muscle activation during LL-BFR training. Possibility of systemic bias in central fatigue due to exercising extensors before flexors. Absence of protein abundance measurements affecting the interpretation of transcriptional responses. Lack of investigation into training adaptations in the central and peripheral neural systems.
Appraisals:
Cochrane risk-of-bias – (4/5) Blinding of participants and personnel: No (by: Colombo, V., Valenčič, T., Steiner, K., Škarabot, J., Folland, J., O’Sullivan, O., & Kluzek, S. (2024). Comparison of Blood Flow Restriction Interventions to Standard Rehabilitation After an Anterior Cruciate Ligament Injury: A Systematic Review. The American journal of sports medicine, 3635465241232002. Advance online publication. https://doi.org/10.1177/03635465241232002)
BTB
Intervention
- Blood Flow Restriction
Dose
- 4 sets of knee extensions and flexions at 40 repetitions maximum (RM) to volitional failure.
- Workload remained constant throughout the intervention.
Periodicity
- 9 exercise sessions 3 times a week
Local/Technic:
- A dynamometric system (HUMAC NORM, CSMi Medical Solutions) was used in isotonic mode. The subject sits with hips in 85° flexion and knee flexion-extension axis aligned with the dynamometer’s rotational axis.
- Partial blood flow restriction was induced using a 13.5-cm wide double-chamber pneumatic cuff with asymmetric pressure (Ischemic Trainer). The cuff inflated to a cumulative pressure of 150 mmHg after warm-up.
- Rest periods: 45 s without reperfusion after the first and third set, 90 s of reperfusion after the second set.
Citation: Kacin, A., Drobnič, M., Marš, T., Miš, K., Petrič, M., Weber, D., Tomc Žargi, T., Martinčič, D., & Pirkmajer, S. (2021). Functional and molecular adaptations of quadriceps and hamstring muscles to blood flow restricted training in patients with ACL rupture. Scandinavian journal of medicine & science in sports,31(8), 1636–1646. https://doi.org/10.1111/sms.13968