Effect of blood flow restriction on muscle strength and stability following foot and ankle injury: A systematic review

Table 1 Characteristics of included studies

Ref.	Title	Study design	Country	Sample size (n)	Male (n)	Female (n)	Age (mean)	Blood flow restriction indication	Study population
Burkhardt et al[16]	Effects of Blood Flow Restriction on Muscle Activation During Dynamic Balance Exercises in Individuals with Chronic Ankle Instability	RCT	United States	25	15	10	20.3	Chronic ankle instability	Young adults with a history of chronic ankle instability
Mahmoud et al[17]	Effect of Blood Flow Restriction as a Stand-Alone Treatment on Muscle Strength, Dynamic Balance, and Physical Function in Female Patients with Chronic Ankle Instability	RCT	Saudi Arabia	39	0	39	23.5	Chronic ankle instability	Female patients with a history of chronic ankle instability
Okamura et al[18]	Effect of Neuromuscular Electrostimulation with Blood Flow Restriction on Acute Muscle Swelling of the Abductor Hallucis	RCT	Japan	48	24	24	21	Injuries associated with a low medial longitudinal arch	University students with abductor hallucis pathology
Wen et al[19]	Effect of Low-Load Blood Flow Restriction Training on Patients with Functional Ankle Instability: A Randomized Controlled Trial	RCT	China	46	20	26	21.9	Functional ankle instability	Young adults with a history of functional ankle instability
Werasirirat and Yimlamai[8]	Effect of Supervised Rehabilitation Combined with Blood Flow Restriction Training in Athletes with Chronic Ankle Instability: A Randomized Placebo-Controlled Trial	RCT	Thailand	16	12	4	20.5	Chronic ankle instability	Collegiate athletes with a history of chronic ankle instability
Clark et al[20]	Effects of Blood Flow Restriction on Balance Performance During Dynamic Balance Exercises in Individuals with Chronic Ankle Instability	Prospective	United States	25	9	16	20.8	Chronic ankle instability	Young adults with a history of chronic ankle instability
Killinger et al[21]	The Effects of Blood Flow Restriction on Muscle Activation and Hypoxia in Individuals with Chronic Ankle Instability	Prospective	United States	19	9	10	21.8	Chronic ankle instability	Young adults with a history of chronic ankle instability
Larsen et al[22]	Blood-Flow Restricted Exercise Following Ankle Fractures	Prospective	Denmark	8	3	5	33	Non-specific ankle fracture	Adults with a history of unilateral ankle fracture
Yow et al[23]	Blood Flow Restriction Training After Achilles Tendon Rupture	Case Series	United States	2	2	0	33.5	Achilles tendon rupture	Male soldiers with a history of left Achilles tendon rupture
Mortensen et al[24]	Low-Load Blood-Flow-Restricted Exercise to Prevent Muscle Atrophy and Decline in Functional Performance in a Patient Recovering from a Malleolus Fracture	Case Report	Denmark	1	0	1	28	Lateral malleolus fracture	Female with a history of lateral malleolus fracture

RCT: Randomized control trial.

Table 2 Evaluation of study bias using the methodological index for non-randomized studies

Ref.	Study design	Study type (comparative or non-comparative)	1: clearly stated aim	2: Inclusion of consecutive patients	3: Prospective collection of data	4: End points appropriate to study aim	5: Unbiased assessment of study end point	6: Follow-up period appropriate to study aim	7: Less than 5% lost to follow up	8: Prospective calculation of the study size	9: Adequate control group	10: Contemporary groups	11: Baseline equivalence of groups	12: Adequate statistical analysis	Total score
Clark et al[20]	Prospective	Comparative	2	2	2	2	2	2	2	0	2	2	2	2	22
Killinger et al[21]	Prospective	Comparative	2	2	2	2	2	2	2	0	2	2	2	2	22
Larsen et al[22]	Prospective	Comparative	2	2	2	2	2	2	2	0	0	0	0	1	15
Yow et al[23]	Case Series	Non-Comparative	2	2	0	2	2	2	2	0	0	0	0	0	12
Mortensen et al[24]	Case Report	Non-Comparative	2	2	0	2	2	2	2	0	0	0	0	0	12

Table 3 Evaluation of study bias using the PEDro scale

Ref.	1. Eligibility criteria specified	2. Random allocation	3. Concealed allocation	4. Groups similar at baseline	5. Subject blinding	6. Therapist blinding	7. Assessor blinding	8. Less than 15% dropouts	9. Intention-to-treat analysis	10. Between-group statistical comparisons	11. Point measures and variability data	Total PEDro score
Burkhardt et al[16]	1	1	0	1	0	0	0	1	0	1	1	6
Mahmoud et al[17]	1	1	1	1	1	1	1	1	0	1	1	10
Okamura et al[18]	1	1	1	1	0	0	1	1	0	1	1	8
Wen et al[19]	1	1	1	1	1	1	1	1	0	1	1	10
Werasirirat and Yimlamai[8]	1	1	1	1	1	0	0	1	0	1	1	8

Table 4 Characteristics of blood flow restriction protocols

Ref.	Limb arterial occlusion Pressure (%)	Location of tourniquet cuff	Total occlusion Time (min)	Repetitions in Set #1	Repetitions in Set #2	Repetitions in Set #3	Repetitions in Set #4	Total number of repetitions	Rest between Sets (sec)	Rest between exercises (min)	Number of exercises performed during visit	Frequency (# visits/week)	Duration of treatment Program (weeks)
Burkhardt et al[16]	80%	Proximal thigh	7.5	30	15	15	15	75	30	5	2	2	1
Mahmoud et al[17]	80%	Proximal thigh	5	10	10	10	N/A	30	10	3	5	3	4
Okamura et al[18]	70%	Proximal thigh	15	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	1	1
Wen et al[19]	80%	2-3 cm proximal to patella	7.5	30	15	15	15	75	30	3	3	2	6
Werasirirat and Yimlamai[8]	80%	Proximal thigh	N/A	30	15	15	15	75	30	N/A	4	3	4
Clark et al[20]	80%	Proximal thigh	8	30	15	15	15	75	30	N/A	4	2	1
Killinger et al[21]	80%	2-3 cm proximal to patella	N/A	30	15	15	15	75	45	5	2	1	1
Larsen et al[22]	60%	Proximal thigh	N/A	30	15	15	15	75	30	N/A	1	2	3
Yow et al[23]	60%	Proximal thigh	N/A	30	15	15	N/A	N/A	30	0-2	5	4	12
Mortensen et al[24]	80%	Proximal thigh	N/A	30	15	15	15	75	N/A	N/A	2	N/A	5
Average	75%		8.6	27.8	14.4	14.4	15	69.4	29.4	4	3.1	2.2	3.8