Thermographic assessment of the immediate and short term-effects of blood flow restriction exercise on Achilles tendon skin temperature

Objectives: To determine the thermal patterning of the Achilles tendon following bodyweight resistance exercise with and without blood-flow restriction (BFR). Design: Cross-sectional. Setting: Research laboratory. Participants: Twelve asymptomatic recreational runners (Age: 37 +/- 10, Height: 169 +/- 20, Mass: 73.8 +/- 13.4). Main outcome measures: Thermograms were taken pre and post exercise with and without a BFR cuff on separate legs. BFR cuff pressure was set at 80% maximal arterial occlusion pressure determined using doppler via the tibial artery. Linear mixed-effects models were used to assess the effect of BFR and time post-exercise on skin-temperature (Tskin). Results: A lower Tskin was seen following BFR exercise at the tendon insertion (P = 0.002), but not at the free tendon (P = 0.234), or the musculotendinous junction (P = 0.933). A significant effect of time upon changes in Tskin was observed in both BFR and non-BFR groups (P = 0.002). No interaction of time and BFR were observed on changes in Tskin (P = 0.726). Conclusion: Region specific changes in Tskin were found, with greater and longer reductions observed at the insertion of the Achilles following BFR exercise before returning to baseline. These findings could have implications for the programming of BFR exercise on tendon health. Future research should observe for differences between symptomatic and healthy tendons. (c) 2021 Published by Elsevier Ltd.

Automated summary

The study aimed to determine the thermal patterning of the Achilles tendon following bodyweight resistance exercise with and without blood-flow restriction. Results showed lower Tskin at the tendon insertion following BFR exercise, with a significant effect of time post-exercise on Tskin changes, but no interaction of time and BFR.