246 



METABOLISM DURING WALKING. 



COMPARISON OF STEP-LIFT IN HORIZONTAL AND GRADE WALKING. 



Although the data for the step-lift as measured may be found scat- 

 tered throughout the tables, it seems desirable to make a direct com- 

 parison of the step-lift in horizontal walking with the step-lift in grade 

 walking as measured by the apparatus pictured in figure 1. Such 

 comparison should, however, be subject to the criticism and at least 

 theoretical corrections brought out in the discussion of the technique 

 on page 31. Using the data for our most frequently employed sub- 

 ject, E. D. B., we have collected in table 67 a series of values comparing 

 the step-lift of this subject during horizontal and grade walking at an 



TABLE 67. Comparison of step-lift of E. D. B. in horizontal and grade walking 

 at an approximate speed of J+5 meters. (Values per minute.) 



average speed of 45 meters. The different grades used in the grade- 

 walking experiments are also indicated. The first half of the table 

 consists simply of a repetition of horizontal walking on different days, 

 and consequently shows no great variation. As a matter of fact, the 

 total step-lift ranged from 0.66 to 1.00 meter per minute on the days 

 selected for comparison, and the step-lift per step from 0.82 to 1.18 cm. 

 Since all of the horizontal- walking data are not here included, it seems 

 unnecessary to assume an average, and it will not be used in the sub- 

 sequent discussion. 



The values for the grade walking are given in the lower part of the 

 table. It will be noted that the distance walked per minute was 

 slightly higher in most instances than in the horizontal walking. Not- 



