A Promising Approach to Effectively Reduce Cramp Susceptibility in Human Muscles: A Randomized, Controlled Clinical Trial

作者：Behringer Michael^*; Moser Markus; McCourt Molly; Montag Johannes; Mester Joachim

来源：PLos One, 2014, 9(4): e94910.

DOI：10.1371/journal.pone.0094910

Background: To investigate if the cramp threshold frequency (CTF) can be altered by electrical muscle stimulation in a shortened position.
Methods: A total of 15 healthy male sport students were randomly allocated to an intervention (IG, n=10) and a non-treatment control group (CG, n=5). Calf muscles of both legs in the IG were stimulated equally twice a week over 6 weeks. The protocol was 3x5 s on, 10 s off, 150 its impulse width, 30 Hz above the individual CTF, and was at 85% of the maximal tolerated stimulation energy. One leg was stimulated in a shortened position, inducing muscle cramps (CT), while the opposite leg was fixated in a neutral position at the ankle, hindering muscle cramps (nCT). CTF tests were performed prior to the first and 96 h after the 6th (3 w) and 12th (6 w) training session.
Results: After 3 w, the CTF had significantly (p<0.001) increased in CT calves from 23.3 +/- 5.7 Hz to 33.3 +/- 6.9 Hz, while it remained unchanged in nCT (pre: 23.6 +/- 5.7 Hz, mid: 22.3 +/- 3.5 Hz) and in both legs of the CG (pre: 21.8 +/- 3.2 Hz, mid: 22.0 +/- 2.7 Hz). Only CT saw further insignificant increases in the CTF. The applied stimulation energy (mA(2)center dot mu s) positively correlated with the effect on the CTF (r = 0.92; p<0.001).
Conclusions: The present study may be useful for developing new non-pharmacological strategies to reduce cramp susceptibility.

• 出版日期2014-4-11