Figure 3

Mean and standard error of compression depth when average at 15 second intervals. a = 15 sec was different from 1 min 30 sec thru 10 min, b = 30 sec was different from 1 min 15 sec thru 10 min. c = 45 sec was different from 2 min 15 sec thru 10 min. d = 1 min was different from 2 min thru 10 min. e = 1 min 15 sec was different from 2 min 30 sec thru 10 min. f = 1 min 30 sec was different from 3 min thru 10 min. g = 1 min 45 sec was different from 3 min 15 sec thru 10 min. h = 2 min and 2 min 15 sec were different from 4 min thru 10 min. i = 2 min 30 sec and 2 min 45 sec were different from 5 min thru 10 min. j = 3 min was different from 7 min 45 sec.