DISCUSSION OF RESULTS. 61 



DISCUSSION OF RESULTS. 

 BASAL VALUES. 



In any study of walking in a horizontal direction, two main prob- 

 lems present themselves: first, the variations in the energy requirement 

 of different individuals for walking varying distances at varying 

 velocities, and second, the actual energy requirement for transporting 

 the body-weight or a superimposed load in a horizontal direction, i. e., 

 the calorie output per horizontal kilogrammeter. 



As has already been noted, the mechanical processes incidental 

 to walking, even at a moderate pace, usually involve some extraneous 

 muscular movements apparently not directly connected with the motion 

 of forward progression, such as the more or less vigorous swinging of 

 the arms and a not inconsiderable raising of the body-weight with each 

 step. Since these extraneous muscular movements do not necessarily 

 have an effective value in transporting the body-weight or the super- 

 imposed load in a horizontal direction, the problem of finding the 

 calorie requirement for such transportation of weight becomes an 

 exceedingly complicated one. 



If the principle of the deduction of basal values for determining the 

 energy required to move 1 kilogram 1 meter in a horizontal direction 

 may be legitimately employed, and this has been the method adopted 

 by all investigators, it becomes an important point as to what should 

 properly be considered as the basal maintenance metabolism in experi- 

 ments when the subject is walking in a horizontal direction. As will 

 be seen by reference to the summary of previous researches given in 

 table 1, investigators have varied considerably in their usage in this 

 respect. Certain members of the Zuntz school have almost invariably 

 employed the resting (lying) metabolism obtained with the subject in 

 the post-absorptive condition. The values found with the subject 

 sitting or stancling quietly have also been used as a basis in determining 

 the metabolism due to the muscular activity of walking. Still another 

 basal value which may be considered is that found when the subject is 

 standing and moving his arms in a manner similar to that employed in 

 more or less rapid walking. Finally it may even be possible to use 

 the metabolism determined during slow walking for a basal value to 

 be deducted from the metabolism found while the subject was walking 

 at a rapid rate. The validity of this assumption will be examined later. 



Bearing in mind the experience of Benedict and Cathcart in attempt- 

 ing to secure a suitable base-line for their bicycle rider, we considered 

 it desirable to study our subjects in varying positions. The positions 

 selected have been outlined in a preceding section. Since we were to 

 make a large number of observations upon each subject, we concluded 

 that the period of adjustment to the type of the experiment would be so 

 short that a moderately constant value could be found in the standing 



