Is BFR Training for tendon related pains superior vs conventional rehab modalities?

In a recent short article at Dansk Sports Medicine a group of researchers elaborate on their concurrent RCT that explores whether Low-load Blood Flow Restriction (BFR) Training is effective in the treatment for patellar tendon related pains.

Currently, at the Department of Sports Medicine at Bispebjerg hospital Denmark, the researchers are exploring the potential benefit of BFR Training in the rehab for tendon related overuse injuries e.g., tendinopathy vs conventional training.

So far, the body of literature appears with contradictory outcomes for the effect of Low-load BFR training vs Conventional high-load training in the treatment for pain and objective parameters of tendon health whether.

That is why this concurrent RCT is an important contribution to this less explored field BFR research and is pertinent before a general recommendation of low-load BFR should be prescribed as a first line rehab modality for tendon related pains and tendinopathy.

Introduction:

Eccentric and Heavy Slow Resistance (HSR) Training, particularly the later, is currently the recommended rehab modality for tendinopathy.

However, exercise modality and type of muscle work does not appear to be decisive, instead the total training volume and time under tension seem to be of importance. And notably, only about 25% experience relevant effects of HSR, after 12 weeks of progressive exercise.

The rational for BFR is inherently the low-load and fatiguing stimuli, with less strain on the joint and tendons, whereby modulation of the damaged tissue may be augmented compared to conventional training.

As presented in a previous post, this case-series from the corresponding group of researchers tested a 3-week training intervention in which they performed 3/weekly low-load BFR as 30% of 1-RM.

6/7 subjects experienced a clinically significant pain reduction (≥50%) measured in with a single-leg decline squat.

+4% quadriceps maximal isometric contraction strength.

-31% Doppler activity in the patellar tendon as an expression of reduced vascularization, which could indicate healing of the tendon tissue.

Preliminary conclusion from the authors:

Because of the methodological shortcomings, as the lack of a control group (not RCT) and few participants, the results need to be interpreted cautiously. But it seems that BFR may be effective in the treatment of tendinopathy!?

As explained, the current evidence is sparse with contradictory results for the effect of Low-load BFR training vs Conventional High-load training in the treatment and objective parameters of tendon health and importantly, considering the relative low success rate with the current recommended HSR Training. That is why, this RCT is an important contribution to the literature and we find it pertinent before a general recommendation of low-load BFR should be prescribed as a first line rehab modality for tendon related pains and tendinopathy.
So, stay tuned for the results of this RCT.

But wait – what is the rational for BFR in this population, if volume and time under tension is thought to be the decisive factors? And why should low-load No-BFR with inherently higher volume not be a better option!? . Any explanations of this opposition?

Primary Source: https://dansksportsmedicin.dk/ front page.. With Google translate as Your companion..

Selection of original articles:
Aagaard et al. (2020) The effect of low-load resistance training with blood flow restriction on chronic patellar tendinopathy – a case series.
Sata (2005). Kaatsu Training for patella tendinitis patient.
Centner et al. (20219) Low-load blood flow restriction training induces similar morphological and mechanical Achilles tendon adaptations compared to high-load resistance training.
Kubo et al. (2006) Effects of low-load resistance training with vascular occlusion on the mechanical properties of muscle and tendon.
Reeves et al. (2006) Comparison of hormone responses following light resistance exercise with partial vascular occlusion and moderately difficult resistance exercise without occlusion.
Makris et al. (2014) Developing functional musculoskeletal tissues through hypoxia and lysyl oxidase-induced collagen cross-linking.
Xia et al. (2006) Nitric oxide enhances collagen synthesis in cultured human tendon cells.