256 METABOLISM DURING WALKING. 



external muscular work. The transportation of the body up-grade 

 or the transportation of a superimposed load, such as was done in many 

 of Durig's experiments, may definitely be classed as "effective" mus- 

 cular work. The step-lift, both with the body and with the superim- 

 posed load, can not be considered in the ordinary process of walking 

 as effective external work. Nevertheless we believe that this treat- 

 ment has distinct physiological interest in the strong suggestion that 

 attention to the type of gait, particularly in minimizing the step-lift, 

 may not be without definite economic importance in considering the 

 human body as an efficient machine. 



EFFECT OF LAMENESS UPON THE EFFICIENCY OF E. D. B. 



As has been stated elsewhere, E. D. B. developed a lameness in the 

 instep of his right foot early in January. As a result, the experiments 

 with him were discontinued for a period of three weeks, beginning with 

 January 10. On inquiry it developed that he had been conscious of 

 some pain in the instep for a number of days, although he had made no 

 complaint. The question accordingly arose whether the lameness was 

 of sufficient moment to vitiate the results of the standing and grade- 

 walking experiments on January 3, 4, and 5. The metabolism data 

 obtained on these days have accordingly been collected in table 73. 

 For comparison, the data are included for the standing experiment of 

 December 31 and the grade- walking experiment of January 1 before 

 the lameness developed, and for the grade-walking experiment of 

 February 4, when the lameness had been cured by three weeks of rest. 



As would be expected, the metabolism during standing was evi- 

 dently not affected, as the data for January 3, 4, and 5 agree well with 

 those obtained on December 31, before the lameness developed. In 

 the grade- walking experiments of January 3 and 4, the values for the 

 energy cost per kilogrammeter and the percentage efficiencies show 

 slight changes from corresponding data obtained on January 1 and 

 February 4; nevertheless the differences are so slight that they may be 

 considered as within the limits of experimental error. The efficiency 

 for the other day (January 5) agrees well with those of January 1 and 

 February 4. There is therefore no reason to discredit the values re- 

 ported for these three days. 



On January 10, when the subject began walking preliminary to the 

 experimental period, the pain in his instep was so severe that it was 

 necessary to end the experiment. The standing data for this day have 

 not been included in any of the tables previously discussed, but are 

 given in table 73. These values show a very slight increase in the 

 carbon-dioxide production and heat-output. Although it was noted in 

 the protocols of the experiment that the subject "stood mostly on the 

 left foot" and "favored his right leg," the difference in the metabolism 

 values is too small to indicate that the subject was standing at a dis- 





