Blood flow restriction training in rehabilitation for knee conditions and elective knee procedures

Table 1 A summary of various blood flow restriction-assisted rehabilitation protocols applied to different knee conditions, their pearls and pitfalls

		Knee conditions
		ACLR	Knee OA and RA	PFS	TKA
BFR-assisted rehabilitation details	Sets	3 to 5	3 to 5	3 to 5	3 or 4, or until volitional fatigue
	Repetitions	10 or 30/15/15/15 protocol	10 or 30/15/15/15 protocol	10 or 30/15/15/15 protocol	30-15-15-15 protocol
	Frequency	Once to five times weekly	Twice to three times weekly	Twice to three times weekly	Twice to five times weekly
	Duration	2-8 weeks	4-12 weeks	4-12 weeks	6-10 weeks (some advised preoperative sessions)
	Load	30% to 60% RM	20% to 30% RM	30% RM	30% to 80% RM
	Restriction pressure	80% LOP	160-200 mmHg, or 50% to 70% LOP	160-200 mmHg, or 70% LOP	40% to 80% LOP
Pearls to consider	Proper patient selection, and better to avoid its usage in patients with peripheral vascular disease, vascular grafts, and active infection. The tourniquet cuff should be applied as proximally in the thigh as possible. Although there are variations in the used cuff width (ranging from 6 cm to 18 cm), wider cuffs are preferred as they have less potential for causing pain. It is preferable to adjust the tourniquet pressure for each patient [some suggested an equation as follows: Restriction pressure = 0.5 (systolic blood pressure) + 2 (thigh circumference) + 5] or by using ultrasound on the femoral or dorsalis pedis arteries). Limb occlusion pressure should always be tested supine with the patient as still as possible. Most protocols recommend 4 sets of 30, 15, 15, and 15 repetitions with a 30-s rest between sets
Pitfalls and drawbacks to avoid	Using inappropriate pressure will lead to an inability to occlude blood flow. Narrow cuffs may lead to more complications and increased pain after training. High pressure may lead to complications such as nerve injury and limb ischemia. Stop training immediately if the patient feels dizziness, lightheadedness, numbness, or severe pain

ACLR: Anterior cruciate ligament reconstruction; OA: Osteoarthritis; RA: Rheumatoid arthritis; PFS: Patellofemoral syndrome; TKA: Total knee arthroplasty; BFR: Blood flow restriction; RM: Repetition maximum; LOP: Limb occlusion pressure.