Journal Information
Vol. 24. Issue 6.
Pages 561-562 (01 November 2020)
Download PDF
More article options
Vol. 24. Issue 6.
Pages 561-562 (01 November 2020)
Letter to the Editor
DOI: 10.1016/j.bjpt.2020.05.006
Full text access
Reply to letter to the Editor about the article “The addition of blood flow restriction to resistance exercise in individuals with knee pain: a systematic review and meta-analysis”
Iván Cuyul-Vasqueza, Héctor Gutiérrez-Espinozab,c,
Corresponding author

Corresponding author.
, Felipe Araya-Quintanillab,d
a Faculty of Health, Therapeutic Process Department, Temuco Catholic University, Temuco, Chile
b Rehabilitation in Health Research Center, CIRES, Universidad de las Américas, Echaurren Street 140, 3rd floor, Santiago, Chile
c Physical Therapy Department, Clinical Hospital San Borja Arriaran, Santiago, Chile
d Faculty of Health Sciences, Universidad SEK, Santiago, Chile

  • The effect of resistance exercise with BRF is not more effective that resistance exercise in in patients with knee pain.

  • Our study was unable to demonstrate the clinical benefits of resistance exercise with BRF in subjects with knee pain.

  • Further studies are needed to support the clinical effect of BRF in pain intensity and knee function in these patients.

Article information
Full Text
Download PDF
Full Text
Dear Editor

We appreciate the comments on our article “The addition of blood flow restriction to resistance exercise in individuals with knee pain: a systematic review and meta-analysis” (Cuyul-Vásquez et al.1). We would like to take the opportunity to address several points raised in these comments.

First, it is important to consider that performing subgroup analyses for meta-analysis with less than 10 studies and with high heterogeneity among the included studies, is not recommended.2,3 In our meta-analysis for pain intensity, the small number of included clinical trials (n = 5), the considerable heterogeneity (i2 = 76%) of these trials, and the lack of plausible interaction, justify our decision not to report a subgroup analysis. We understand how the contrast between the results of previous investigations and the findings of our study could be questioned. For this reason, in response to your letter, we performed a subgroup analysis for pain intensity, independently combining studies that used high intensity versus low intensity resistance exercises in the control group.

The comparison between low intensity resistance exercise (30%-1RM) combined with blood flow restriction (BFR) versus high intensity resistance exercise (70% -1RM),4–6 showed no benefits of BFR for pain relief (pooled SMD = -0.08, 95% CI = -0.41, 0.26, p = 0.66, I2: 0%). For the comparison between low intensity resistance exercise (30%-1RM) with or without BFR, 4,7,8 the pooled SMD also showed no added effectiveness of BFR on pain relief (SMD= -0.51, 95% CI = -1.57, 0.55, p = 0.34, I2: 87%). Therefore, both comparisons are not statistically and clinically significant.9 While this subgroup analysis is affected by the limitations described in the first point of this letter, these findings support the conclusions of our systematic review with meta-analysis, that adding BFR to resistance exercise does not provide additional benefits to decrease knee pain.1

Conflicts of interest

The authors declare no conflicts of interest.

I. Cuyul-Vásquez, A. Leiva-Sepúlveda, O. Catalán-Medalla, F. Araya-Quintanilla, H. Gutiérrez-Espinoza.
The addition of blood flow restriction to resistance exercise in individuals with knee pain: A systematic review and meta-analysis.
Braz J Phys Ther, 24 (2020), pp. 465-478
M. Richardson, P. Garner, S. Donegan.
Interpretation of subgroup analyses in systematic reviews: A tutorial.
Clin Epidemiol Glob Heal, 7 (2019), pp. 192-198
Higgins JPT, Thomas J, Chandler J., Cumpston M., Li T., Page M.J., Welch VA. Cochrane Handbook for Systematic Reviews of Interventions version 6.0 (updated July 2019). Cochrane, 2019. Available from
R.B. Ferraz, B. Gualano, R. Rodrigues, et al.
Benefits of resistance training with blood flow restriction in knee osteoarthritis.
Med Sci Sports Exerc, 50 (2018), pp. 897-905
F.F. Bryk, A.C. dos Reis, D. Fingerhut, et al.
Exercises with partial vascular occlusion in patients with knee osteoarthritis: A randomized clinical trial.
Knee Surg Sports Traumatol Arthrosc, 24 (2016), pp. 1580-1586
L. Giles, K.E. Webster, J. Mcclelland, J.L. Cook.
Quadriceps strengthening with and without blood flow restriction in the treatment of patellofemoral pain: A double-blind randomised trial.
Br J Sports Med, 51 (2017), pp. 1688-1694
N. Segal, M.D. Davis, A.E. Mikesky.
Efficacy of blood flow-restricted low-load resistance training for quadriceps strengthening in men at risk of symptomatic knee osteoarthritis.
Geriatr Orthop Surg Rehabil, 6 (2015), pp. 160-167
N.A. Segal, G.N. Williams, M.C. Davis, R.B. Wallace, A.E. Mikesky.
Efficacy of blood flow-restricted, low-load resistance training in women with risk factors for symptomatic knee osteoarthritis.
A.C. Lee, J.B. Driban, L.L. Price, W.F. Harvey, A.M. Rodday, C. Wang.
Responsiveness and minimally important differences for 4 patient-reported outcomes measurement information system short forms: Physical function, pain interference, depression, and anxiety in knee osteoarthritis.
J Pain, 18 (2017), pp. 1096-1110
Copyright © 2020. Associação Brasileira de Pesquisa e Pós-Graduação em Fisioterapia
Brazilian Journal of Physical Therapy

Subscribe to our newsletter

Article options
en pt
Cookies policy Política de cookies
To improve our services and products, we use "cookies" (own or third parties authorized) to show advertising related to client preferences through the analyses of navigation customer behavior. Continuing navigation will be considered as acceptance of this use. You can change the settings or obtain more information by clicking here. Utilizamos cookies próprios e de terceiros para melhorar nossos serviços e mostrar publicidade relacionada às suas preferências, analisando seus hábitos de navegação. Se continuar a navegar, consideramos que aceita o seu uso. Você pode alterar a configuração ou obter mais informações aqui.