Quadriceps training with blood flow restriction in knee pain
Conservative measures are often used as a first line of treatment against patellofemoral pain (PFP), as quadriceps strengthening has been proven efficacious in improving pain and function. A common challenge faced by clinicians is the administration of the appropriate loads to enact change without aggravating symptoms. The authors of this study conducted a randomized control trial to investigate the effects of blood flow restriction (BFR) training on PFP. In comparison to standard strength training, BFR had improved pain with ADL in the short term and improved strength in those with painful knee extension however, provided no difference in any outcomes at 6 months.
PFP often includes pain and muscle weakness and is associated with atrophy of the quadriceps musculature. The supported causative effect of increase in patellar joint surface contact area as a result of quadriceps strengthening has had proven positive effects on pain and function, however the equal increase in patellar joint pressure has been postulated as a cause of PFP making application of exercise difficult for some. The addition of BFR was thought to provide an opportunity to achieve strength effects at sub-threshold pain levels.
This RCT prospectively compared the 2 groups over an 8-week period and again at 6 months. Outcomes involving pain with ADL, peak pain reports, peak strength and muscle thickness were measured for comparison. Although limitations did exist that would warrant further research, the authors support the potential for BFR training as an alternative in the treatment of PFP in the short term when compared to standard strengthening practices.
> From: Giles et al., Br J Sports Med (2017) (Epub ahead of print). All rights reserved to BMJ Publishing Group Ltd. Click here for the online summary.