The authors would like to make the following two corrections: Reference 138 incorrectly cited a protocol report rather than the full report that was reviewed by the authors. The original reference (138: Ebadi S, Ansari NN, Henschke N, Naghdi S, Tulder MW. The effect of continuous ultrasound on chronic low back pain: protocol of a randomized controlled trial. BMC Musculoskelet Disord. 2011; 12: 59) should be replaced with 138: Ebadi S, Ansari NN, Naghdi S, et al. The effect of continuous ultrasound on chronic non-specific low back pain: a single blind placebo-controlled randomized trial. BMC Musculoskelet Disord. 2012;13:192. 10.1186/1471-2474-13-192. This citation error had no impact on the authors’ evaluation of the full report. Additionally, the recommendation, “In patients with chronic low back pain, ultrasound is not recommended to improve functional outcomes [137,138]. Grade of Recommendation: A” should be corrected to, “It is suggested that ultrasound does not improve functional outcomes in patients with chronic low back pain [137,138]. Grade of Recommendation: B” due to the levels of evidence of the supporting references. The authors would like to apologize for any inconvenience caused.
Bibliographical notePublisher Copyright: