32 METABOLISM DURING WALKING. 



plate, and the distance on the 1 -meter scale, it was found that in walk- 

 ing on a level there was an average total forward-and-back movement 

 at the waist of 1.98 cm., and at the shoulder of 0.79 cm., corresponding 

 to a displacement from the vertical of 0.99 and 0.40 cm., respectively, 

 while for the 10 and 25 per cent grades the displacement was even less. 

 For a radius of 1.5 meters, which represents the length of the cord from 

 the shoulders to the pulley, and which connects the subject with the 

 step-lift counter, this displacement would amount to a rise above the 

 horizontal of 0.01 cm., an amount too small to be considered. 



A comparison was also made at this time between the respective 

 readings of the perpendicular lift, as shown by the light spot at the waist 

 (Benedict and Murschhauser method), and that at the shoulder 

 (H. M. S. method), and of the kymograph tracings taken simul- 

 taneously. On one series of plates it was found that, for horizontal 

 walking, the movement of the light spot at the waist was larger than 

 that at the shoulder by 1 per cent, while the movement of the shoulder 

 light spot was greater than that recorded by the kymograph by 1.5 

 per cent. On another series of plates it was found that the shoulder 

 movement was slightly larger than the waist movement. In either 

 case it may be assumed that the variations agree within 1 or 2 per cent 

 of each other. In the case of the grade walking the differences were of 

 the same order. 



Measurements were likewise made with the subject walking up the 

 inclined treadmill when it was stationary and again when it was 

 running. The subject with the light at the waist stepped from a stool 

 on to the treadmill and walked to the top, thus giving an opportunity 

 for the measurement of the step-lift superimposed on the grade-lift. 

 The mill was at an incline of 18.4 per cent. By measuring the light 

 spots recorded on the plate when the subject walked up the stationary 

 mill, it was computed that the grade was 14.7 per cent, i. e., the light 

 spots did not correctly show the grade by 3.7 per cent. From the 

 plates made when the subject walked up the mill while it was running, 

 the grade, computed from the light spots, was 19.9 per cent, or 1.5 per 

 cent too high. Evidently the measurements of the step-lift can only 

 be regarded as approximate. 



The average step-lift, measured under these conditions, was 5.23 and 

 6.48 cm. per step, respectively, with the mill stationary and running. 

 Assuming 110 steps a minute, there was a lift of approximately 7 meters 

 per minute when the mill was running. From table 55 (see p. 214), 

 we find that E. D. B. on December 15, walking on a 15 percent grade and 

 with a speed of 75 meters per minute, had an average step-lift of 4.89 

 meters per minute, as measured by the kymograph; and on January 1, 

 with a 20 per cent grade and a speed of 80 meters per minute, it 

 was 5.57 meters per minute. If these figures are increased by 1.5 per 

 cent to correspond with the measurements from the photographic 



