Ischemic preconditioning attenuates pain perception following eccentric exercise - a crossover-study

Jokumsen, Peter Sørensen ; ter Beek, Frank ; Bentzon, Sabrina Mosegaard ; Hansen, Casper Østergaard

4. semester

Sports Science, Master

2018

2018-02-25

14

Baggrund: Når blodforsyningen til væv afbrydes (iskæmi) og derefter gendannes (reperfusion), kan det udløse inflammation, øget calcium inde i cellerne og reaktive iltforbindelser (ROS), som skader cellemembranen og kan føre til celledød. Iskæmisk præconditioning (IPC) er korte, kontrollerede afbrydelser af blodtilførslen, som tidligere er vist at kunne begrænse vævsskade. Træningsudløst muskelskade efter excentrisk arbejde (når musklen arbejder, mens den forlænges) deler flere af de samme biologiske kendetegn. Formålet var at undersøge, om IPC kan reducere kendte markører for sådan muskelskade efter excentrisk træning. Metoder: Elleve raske frivillige gennemførte begge betingelser i et randomiseret cross-over-design: IPC (en stram blodtryksmanchet, oppumpet i korte intervaller) og sham (en manchet med meget lavt tryk). Umiddelbart efter hver betingelse udførte deltagerne 5 sæt af 10 kontrollerede excentriske kontraktioner af tibialis anterior, musklen på forsiden af skinnebenet, på en specialbygget platform. Vi målte muskelstivhed (med shear wave elastografi), muskeltykkelse/hævelse (med B-mode ultralyd), muskelstyrke (maksimal frivillig kontraktion) og oplevet smerte (numerisk ratingskala) før indgrebet, lige efter træning samt 24 og 48 timer efter. Smerte blev desuden registreret 72, 96, 120 og 144 timer efter. Resultater: Oplevet smerte steg i begge betingelser sammenlignet med udgangspunktet og frem til 48 timer, uden overordnet forskel mellem IPC og sham. Ved 72 timer sås dog kun en yderligere stigning i smerte efter sham, ikke efter IPC. Muskeltykkelsen var øget 24 og 48 timer efter, men uden forskel mellem betingelser. Der sås ingen signifikante ændringer i muskelstivhed eller muskelstyrke. Konklusion: IPC kan muligvis dæmpe oplevet smerte efter excentrisk træning af tibialis anterior, men påvirkede ikke muskelstivhed, hævelse eller styrke i denne undersøgelse.

Background: When blood flow to tissue is cut off (ischemia) and then restored (reperfusion), it can trigger inflammation, higher calcium inside cells, and reactive oxygen species (ROS) that damage cell membranes and may lead to cell death. Ischemic preconditioning (IPC)—brief, controlled reductions in blood flow—has been shown to limit tissue injury. Exercise-induced muscle damage after eccentric work (when a muscle lengthens under load) shares several of these biological features. This study asked whether IPC can reduce known markers of such muscle damage after eccentric exercise. Methods: Eleven healthy volunteers completed both conditions in a randomized crossover design: IPC (a tight blood-pressure cuff inflated in short bouts) and sham (a cuff at very low pressure). Immediately afterward, participants performed 5 sets of 10 controlled eccentric contractions of the tibialis anterior, the muscle at the front of the shin, on a custom-built platform. We assessed muscle stiffness (shear wave elastography), muscle thickness/swelling (B-mode ultrasound), muscle strength (maximal voluntary contraction), and perceived pain (numeric rating scale) before the procedure, immediately after exercise, and 24 and 48 hours later. Pain was also recorded at 72, 96, 120, and 144 hours. Results: Perceived pain rose from baseline in both conditions up to 48 hours, with no overall difference between IPC and sham. However, only the sham condition showed a further increase in pain at 72 hours; IPC did not. Muscle thickness increased at 24 and 48 hours, with no differences between conditions. There were no significant changes in muscle stiffness or muscle strength. Conclusion: IPC may reduce perceived pain after eccentric exercise of the tibialis anterior but did not affect muscle stiffness, swelling, or strength in this study.

[This abstract was generated with the help of AI]

Ischemic Preconditioning ; Exercise-induced muscle damage ; IPC ; EIMD ; Ultrasound ; Shear Wave Elastography ; MVC ; Pain ; NRS ; DOMS

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Jokumsen, Peter Sørensen:

• Ischemic preconditioning does not improve maximal power output or maximal oxygen consumption but attenuates rating of perceived exertion - a crossover study (2019)

ter Beek, Frank:

• Ischemic preconditioning does not improve maximal power output or maximal oxygen consumption but attenuates rating of perceived exertion - a crossover study (2019)

Bentzon, Sabrina Mosegaard:

• Recognition in the Danish Defence (2019)