Title: Effects of Whole-Body Vibration on Bone Mineral Density in Postmenopausal Women:
An Overview of Systematic Reviews
Version: 2 Date: 08 Jul 2024
Reviewer's report:
The introduction provides a strong rationale as to the significance of this work. I commend the
authors for this very thorough analysis.
A major flaw of this paper is the lack of consideration of bone health in postmenopausal
women. In postmenopausal women, it is physiologically expected for BMD to decline without
any intervention.  Thus, if WBV or other intervention, can help maintain BMD, while others
(controls) experience a loss, this would still be clinically important for reducing risk for
fracture and/or prevention of osteoporosis.  The authors of this paper have neglected to consider
maintenance of BMD as a benefit to health. Considering this, the SRs should be reevaluated
because even a maintenance of BMD in postmenopausal women, in comparison to a decline in
non-exercising (control) populations, should still be considered as a positive outcome of WBV
use. I agree with the author’s conclusions, however, is there not value for a postmenopausal
woman to maintain BMD via use of WBV?  Prevention of bone loss is important for avoiding
osteoporosis and fracture. This should be further explored in order to be an accurate and
comprehensive paper which is useful for postmenopausal women.
I recommend a more thorough explanation of the “overview method” in the introduction of this
paper.  P. 4, beginning line 96. Why is the overview method better than previous methods?  What
further information does it add compared to methods used in published reviews?
P. 4 line 98 reference #22 seems inappropriate, the authors are citing a paper that uses the
overview method rather than citing Pollock et al. 2016 which describes the method itself.
Section 2.3 “Inclusion criteria” should be written with verbs in the past tense. For example, “If
an SR included RCTs recruiting both males and females, we read the full text, if the SR provided
a separate textual summary or meta-analysis for postmenopausal women, it was included.”
p. 5 line 117 “SRs and meta-analysis of randomized controlled trials (RCTs)” is not a complete
sentence.
The last paragraph of section 2.5 needs to be written with verbs in the past tense. Line 150-153
Section 2.7 – can the authors further explain the concept of “overlap” as calculated using CCA?
Line 204 When presenting Table 1, authors should explain what is meant by the variable,
magnitude (g). Does this refer to the amplitude of the WBV platform displacement?  Use of the
term magnitude needs greater explanation in general.
Table 2 needs to stand alone, so the AMSTAR-2 quality items 1-16 need to be provided in a
footnote.
Line 227, what do authors mean by “overall” BMD, does this refer to "whole body" BMD? This
should be specified.  If “overall” BMD really refers to whole body BMD, the use of whole body
should replace “overall” throughout the paper. (line 287)
Section 3.4 line 227. I recommend rearranging section 3.4 by anatomical bone site with femoral
neck first, followed by trochanter, total hip, lumbar spine, and then whole body. Clinically,
femoral neck may be the most relevant site for bone health and assessment of fracture risk. It
makes sense to present all the hip data together, then move on to another anatomical site.  The
Ward’s area has been shown to be irrelevant for clinical use and I recommend removing it from
the paper all together.
Table 4 – Add horizontal lines or shading to help differentiable the data from different studies.
In the current state, it is difficult to determine which information corresponds to which study.
Section 3.5 – reword the title of this section to accurately convey this section of your paper is
a review of the conclusions made by the authors of the previously published papers. As is, this
title may be interpreted that the section indicates your opinions.
Line 286 and 298 “top” should read “total”.
Line 296 -  In section 3.4 lumbar spine – the authors indicate that the 3 studies which found
“that WBV had a statistically significant difference in improving lumbar spine BMD” have
"moderate" certainty of evidence. However, in the discussion the authors indicate a "low"
certainty of evidence for these 3 studies.  This discrepancy needs to be corrected. If there truly
is moderate certainty of evidence in 3/8 studies, can we still confidently conclude that WBV is
not recommended for improving BMD at the spine?
Line 337-338, rewrite as “The subjectivity of the assessment tools and potential biases in our
understanding of these tools may influence on our final results.”