The effects of the Aussie current on pain, torque and muscle strength: Systematic review

The Aussie Current (AC) is a medium frequency electrical current of 1 and 4 kHz modulated in bursts used to reduce pain, increase muscle strength and produce torque in adults. However, there is still no consensus on these effects.

To systematically review available evidence on the effects of AC on pain, muscle strength, torque, comfort and functionality in adults.

This systematic review was conducted according to PRISMA guidelines and registered in PROSPERO. A search was carried out in the Lilacs, Scielo, Web of Science, Scopus, Pubmed and PEDro databases, from 10/2021 to 02/2022. Randomized or non-randomized clinical trials that investigated the effects of the application of AC were selected. Two reviewers independently assessed the risk of bias in the studies using the JADAD scale. The quality of the evidence of some outcomes was assessed using the GRADE system of rating The selected studies used AC as intervention and presented pain, muscle strength, torque, comfort and/or functionality as outcomes.

21 studies (590 participants) were included. 14 articles were classified as low quality and 7 as high quality. The quality of the evidence was moderate. The effects of AC on the studied outcomes are still controversial. As for the consensus regarding the chosen frequency, 80,9% (n = 17) of the studies used the frequency of 1 kHz.

Although it was verified that the frequency of 1 kHz is the most used, the studies that address AC are scarce and with methodological diversity, which makes it difficult to assess the effectiveness of this current. Thus, we suggest that further studies should be carried out to elucidate the effects of AC on pain, muscle strength and torque production.