Reviewer's report 
 The effect of straining on the diaphragmatic crura with identification of the straining-crural Title: 
reflex. The reflex theory in gastroesophagael competence: a new concept 
 1  16 February 2004 Version: Date: 
 James Francis Xavier FX Jones Reviewer: 
Reviewer's report: 
General 
The manuscript by Shafik et al. is an interesting exploration of human crural diaphragm function. The 
results relating to local anesthesia of the muscle are particularly interesting. 
------------------------------------------------------------------------------- 
Major Compulsory Revisions (that the author must respond to before a decision on publication can 
be reached) 1. In order to determine that any response is a reflex the afferent signal that is "reflected" in the central 
nervous system must be elucidated as well as the efferent arc. The authors have not done this. 
Lidocaine infiltration will remove efferent and afferent pathways. 
In other words how do the authors know that the crural activation during straining or coughing is part 
of a motor programme transmitted to the crural branch of the 
phrenic nerve and with no reflex component at all (to augment the sphincteric response)? I can 
empathasise somewhat with the authors, as human experimentation is very difficult and can never be harmful to the patient. Perhaps the manuscript can be written up as the "straining-crural response" and the reflex theory can be left just that, a theory. 
2. 
It must be made clear in the methods how the stimuli were so precisely timed (in the millisecond range). 
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Minor Essential Revisions (such as missing labels on figures, or the wrong use of a term, which the author can be trusted to correct) P2 line 6 (10 men and 6 women) 
P2 line 22 "competence mechanism" 
P2 line 23 gastro-esophageal P4 line 10 "swallow studies" "gut endoscopy yielded normal.." P5 3rd paragraph "...coughing and straining via laryngeal and tracheal stimulation by moving the 
enodtracheal tube." 
P6 line 2 "...activity with a mean.." P8 line 8 A delta ------------------------------------------------------------------------------- 
Discretionary Revisions (which the author can choose to ignore) 
P4 line 10 
"Laboratory work" is very vague. 
P7 The CD does not share the respiratory movements with the costal diaphragm. 
The CD has respiratory rhythm but is not a respiratory muscle. 
 Accept after minor essential revisions What next?: 
 An article whose findings are important to those with closely related research Level of interest: 
interests 
 Needs some language corrections before being published Quality of written English: 
 No Statistical review: 
Declaration of competing interests: 
None 
Reviewer's report 
 The effect of straining on the diaphragmatic crura with identification of the straining-crural Title: 
reflex. The reflex theory in gastroesophagael competence: a new concept 
 1  16 February 2004 Version: Date: 
 James Francis Xavier FX Jones Reviewer: 
Reviewer's report: 
General 
The manuscript by Shafik et al. is an interesting exploration of human crural diaphragm function. The 
results relating to local anesthesia of the muscle are particularly interesting. 
------------------------------------------------------------------------------- 
Major Compulsory Revisions (that the author must respond to before a decision on publication can 
be reached) 1. In order to determine that any response is a reflex the afferent signal that is "reflected" in the central 
nervous system must be elucidated as well as the efferent arc. The authors have not done this. 
Lidocaine infiltration will remove efferent and afferent pathways. 
In other words how do the authors know that the crural activation during straining or coughing is part 
of a motor programme transmitted to the crural branch of the 
phrenic nerve and with no reflex component at all (to augment the sphincteric response)? I can 
empathasise somewhat with the authors, as human experimentation is very difficult and can never be harmful to the patient. Perhaps the manuscript can be written up as the "straining-crural response" and the reflex theory can be left just that, a theory. 
2. 
It must be made clear in the methods how the stimuli were so precisely timed (in the millisecond range). 
------------------------------------------------------------------------------- 
Minor Essential Revisions (such as missing labels on figures, or the wrong use of a term, which the author can be trusted to correct) P2 line 6 (10 men and 6 women) 
P2 line 22 "competence mechanism" 
P2 line 23 gastro-esophageal P4 line 10 "swallow studies" "gut endoscopy yielded normal.." P5 3rd paragraph "...coughing and straining via laryngeal and tracheal stimulation by moving the 
enodtracheal tube." 
P6 line 2 "...activity with a mean.." P8 line 8 A delta ------------------------------------------------------------------------------- 
Discretionary Revisions (which the author can choose to ignore) 
P4 line 10 
"Laboratory work" is very vague. 
P7 The CD does not share the respiratory movements with the costal diaphragm. 
The CD has respiratory rhythm but is not a respiratory muscle. 
 Accept after minor essential revisions What next?: 
 An article whose findings are important to those with closely related research Level of interest: 
interests 
 Needs some language corrections before being published Quality of written English: 
 No Statistical review: 
Declaration of competing interests: 
None 
Please review this paper.
user
Reviewer's report 
 The effect of straining on the diaphragmatic crura with identification of the straining-crural Title: 
reflex. The reflex theory in gastroesophagael competence: a new concept 
 1  16 February 2004 Version: Date: 
 James Francis Xavier FX Jones Reviewer: 
Reviewer's report: 
General 
The manuscript by Shafik et al. is an interesting exploration of human crural diaphragm function. The 
results relating to local anesthesia of the muscle are particularly interesting. 
------------------------------------------------------------------------------- 
Major Compulsory Revisions (that the author must respond to before a decision on publication can 
be reached) 1. In order to determine that any response is a reflex the afferent signal that is "reflected" in the central 
nervous system must be elucidated as well as the efferent arc. The authors have not done this. 
Lidocaine infiltration will remove efferent and afferent pathways. 
In other words how do the authors know that the crural activation during straining or coughing is part 
of a motor programme transmitted to the crural branch of the 
phrenic nerve and with no reflex component at all (to augment the sphincteric response)? I can 
empathasise somewhat with the authors, as human experimentation is very difficult and can never be harmful to the patient. Perhaps the manuscript can be written up as the "straining-crural response" and the reflex theory can be left just that, a theory. 
2. 
It must be made clear in the methods how the stimuli were so precisely timed (in the millisecond range). 
------------------------------------------------------------------------------- 
Minor Essential Revisions (such as missing labels on figures, or the wrong use of a term, which the author can be trusted to correct) P2 line 6 (10 men and 6 women) 
P2 line 22 "competence mechanism" 
P2 line 23 gastro-esophageal P4 line 10 "swallow studies" "gut endoscopy yielded normal.." P5 3rd paragraph "...coughing and straining via laryngeal and tracheal stimulation by moving the 
enodtracheal tube." 
P6 line 2 "...activity with a mean.." P8 line 8 A delta ------------------------------------------------------------------------------- 
Discretionary Revisions (which the author can choose to ignore) 
P4 line 10 
"Laboratory work" is very vague. 
P7 The CD does not share the respiratory movements with the costal diaphragm. 
The CD has respiratory rhythm but is not a respiratory muscle. 
 Accept after minor essential revisions What next?: 
 An article whose findings are important to those with closely related research Level of interest: 
interests 
 Needs some language corrections before being published Quality of written English: 
 No Statistical review: 
Declaration of competing interests: 
None 
assistant