Intramuscular Properties of Resting Lumbar Muscles in Patients with Unilateral Lower Limb Amputation

Round 1

Reviewer 1 Report

In this paper the authors investigate the effect of lower limb amputation (LLA) on low back pain (LBP). In particular, this is achieved by investigating the stiffness characteristics of lower and upper lumbar muscles via a handheld myotonometer. The dynamic stiffness, oscillating frequency and logarithmic decrement are measured in patients with and without LLAs. The comparison between the obtained results provided information about the influence of LLAs on the different activation, stiffness and elasticity of lumbar muscles between the LLA patients and the control group, suggesting the possible role of LLAs on the occurrence of chronic LBP.

The manuscript is interesting, fits well with the aim of the “Applied Sciences” Journal, and can be accepted for publication after the described minor revisions.

Specifically:

(1) A brief explanation and comments about the t-values reported in Table 1 should be provided.

(2) A picture of the use of the myotonometer during the test should be provided in section 2.2, so that the reader might have a clearer idea of how the test was actually carried out. A synthetic figure representing a typical signal extracted from the instrument should be provided as well, where the authors indicate the meaning of the fundamental features extracted for analysis, namely the dynamic stiffness, the oscillating frequency and the logarithmic decrement. The physical meaning of the maximum acceleration and amplitude of displacement signal could be better represented via this new figure. This would surely improve the quality of the paper and allow to understand the experiment and results more easily.

(3) Similarly to what requested for the t-value in Table 1, a brief explanation and comments about the F values and Tukey HSD in Table 4 should be provided. Also, in the Tukey HSD column, I see various "NS" labels, assuming they stand for “Not significant”. However in the same table they report the same acronym “NS”, standing for “Non-amputated side”. Be careful about the conflict and adjust.

(4) At lines 394-396, it is written: “As mentioned above, in this study, the erector spinae muscle, which corresponds to the inflection point of the thoracolumbar curvature [42], where a high load [33] and rotational forces [43] occurs in the upper lumbar region (T12–L1) is included”. It seems that some verb is missing. Please correct.

(5) Finally, the authors explained very clearly throughout the text the possible occurrence of LBP due to LLA as a result of various causes (LLD, asymmetric trunk-pelvic movement, etc.). Just as a final minor suggestion, it would be great if the authors inserted a figure (maybe in the introduction), schematically representing how these imbalances occur during the motion, highlighting all the important muscles contributing to it.

According to what said above, the reviewer’s opinion is that the manuscript can be accepted for publication after the described minor revisions.

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 2 Report

The manuscript is well presented and follows the aim&scope of the journal. It presents the scope correctly and does not really present major fixes. Only minor points need to be solved before the publication.

In the abstract, abbreviations should be avoided. Authors could fix it.

Figure 1 is not clear, authors could update a better image to increase interest in reading.

The discussion is too long. Readers may lose the train of thought. I suggest reducing it and place the attention on the study's aim. Even if the citation to gait analysis muscular activity is worth it, the somewhat controversial speech can lead the reader to lose interest in the work. 

L353 Shojaei citation, probably the software missed to change it to citation style. 

In the conclusion please highlight better the scientific/clinical relevance of your work. Please provide a clear message of the importance of this paper in the scientific community.

Author Response

Please see the attachment

Author Response File: Author Response.docx