Changes in tendon blood circulation and heart rate variability after intermittent compression to patellar and Achilles tendons

Effects of Static Stretching on the Blood Circulation of Human Tendon In Vivo

“…Previous studies demonstrated that hyperthermia, acupuncture, hyperbaric oxygen therapy, and repeated eccentric contractions increased blood volume and oxygen saturation of the tendons [ 10 – 13 ]. More recent study has also reported that acupressure stimulation, which imposes a short-axis mechanical load on the tendon, enhances tendon blood circulation [ 19 ]. In the present study, we examined whether the tendon blood circulation changes due to static stretching, which was a mechanical stimulus in the long-axis direction of the tendon.…”

“…In the recovery period after static stretching, the reason for the lack of change in tendon blood circulation may be related to insufficient mechanical stimulation of the tendon compared to acupressure and repeated muscle contractions [ 10 , 19 ]. Although different from stretching, in repeated muscle contractions, tendon blood volume did not change under long-duration conditions in isometric contractions but increased after short-duration (i.e., cyclic) contractions [ 20 ].…”

“…Our previous study on acupuncture stimulation showed a significant negative correlation between heart rate changes and tendon THb during the recovery period, suggesting that the autonomic nervous system is involved in controlling tendon blood circulation after acupuncture stimulation [ 11 ]. Conversely, a positive correlation was observed between the changes in tendon blood volume and heart rate during the recovery period with acupressure stimulation, suggesting that increased tendon metabolism due to acupressure stimulation is associated with increased heart rate [ 19 ]. The present study found a high positive correlation between the changes in tendon THb and heart rate only in the 2 min of static stretching ( Figure 6 ).…”

“…However, to our knowledge, no direct relationship between stretching-induced changes in muscle blood flow and central hemodynamic response has been examined. Regarding tendon blood circulation, our previous studies showed that the changes in tendon blood volume during the recovery period after acupuncture and acupressure stimulation were significantly associated with the change in heart rate [ 11 , 19 ]. Thus, if stretching causes changes in tendon (and muscle) blood circulation, the changes in muscle and tendon blood circulation would be related to the changes in the heart rate.…”

Effects of acupuncture and acupressure of the acupoint compared to the tendon on the blood circulation of human tendon in vivo

“…The healing mechanisms of tendon disorders with these therapies included improved blood circulation of the tendons (Chen et al 2001 ; Greve et al 2012 ; Praxitelous et al 2018 ). In fact, our studies showed that blood volume and oxygen saturation of the human tendons increased after acupuncture and acupressure (Kubo et al 2010 , 2011 , 2020a , b ; Yasuda et al 2022 ). In all of these studies, acupuncture and acupressure were directly applied to the tendons.…”