Warming Up. 17 



It fell to my lot in the psychological laboratory, at 

 Clark University, to determine if possible exactly what hap- 

 pens in this warming up process and whether the cause is 

 located in the brain, muscle, or elsewhere. The results ob- 

 tained were certainly suggestive. Having in mind the work 

 done by Mf)Sso, and especially the closely related work of 

 Lombard, we began in a similar way with the ergograph, 

 which is a machine for measuring work done by registering 

 the height to which the weight is lifted each time. We used 

 the middle finger of the right band. The muscles are so 

 closely related in the forearm, and in some persons probably 

 grown together to such an extent that the experiment there 

 was valueless. When one combination of muscle fibers fa- 

 tigued, another took its place and the finger could be worked 

 with considerable power, though variable, all the time. We 

 then arranged a thimble for the index finger and a hand rest, 

 to which the hand was bound so that it could not be tilted to 

 allow a bending of the finger, thus having but one motion 

 possible — that of separating the index from the other fingers 

 by the use of the abductor indicis, which is a y-sha^aed 

 muscle between the first joints of the thumb and index. 

 Being separate from all others, this muscle can be used for 

 an exact record. The marks in the curve represent the 

 height to which the weight was pulled each time. 



Ten or twelve subjects were tried, though most of the 

 results were gained from four or five. The others were used 

 to verify the work. Some of the experiments were so painful 

 that they were not often repeated. 



The two curves (see Plate 3), No. 8 taken January 19 and 

 No. 35 taken May 9, show the general effect of warming up 

 on one subject whom we may call G. They show, too, the 

 value of exercising a muscle regularly, since 530 grams at 

 first fatigued the muscle in about 95 seconds while in May 

 795 grams produced the same effect in 115 seconds. The 

 weight was pulled once every second at the swinging of a 

 pendulum. (These curves have been reduced but the general 

 character remains.) 



