Arbeitsphysiologische Studien

Mechanical work and efficiency in level walking and running

“…The lines indicating the net energy expenditure (total minus standing) in Fig. 3 are in agreement with the oxygen consumption data of Atzler & Herbst (1927), Margaria (1938), Ralston (1958), Cotes & Meade (1960) and Dill (1965) on normal subjects. The dotted part of these curves indicates that an oyxgen debt may be necessary to meet the mechanical power output.…”

Validation of Physical Activity Monitors in Individuals with Diabetes: Energy Expenditure Estimation by the Multisensor SenseWear Armband Pro3 and the Step Counter Omron HJ-720 Against Indirect Calorimetry During Walking

“…Also, this smaller group was subjectively more comfortable with the speed of 4 km/h than 3 km/h. This apparent contradiction may be explained by the fact that the dependence of EE on speed is not linear, 22,23 and a certain U-shape curve rendering the dependence of EE on speed can be envisaged, where the present group of eight subjects in question would be situated somewhere on the concavity of this shape at the speed of 4 km/h. It may also depend on the fact that many of the participants had only little experience with the treadmill and that not even a trial stage before the testing itself was sufficient for them to get used to the movement, to keep balance and walk naturally.…”

“…When evaluating the Omron accelerometer during walking on a level surface (treadmill walking), we found out that this instrument is based on an almost linear correlation between the number of steps and EE. However, it is an established fact that this actual relation is not a purely linear one 22,23 and that, especially at speeds over 6 km/h, EE increases much more quickly than what would correspond to a simple linear increase. In our opinion, this is the main reason why in the above-mentioned studies 13,20 the highest underestimation was found at the highest tested speed of 6.4 km/h.…”

How people initiate energy optimization and converge on their optimal gaits

“…Human walking is a system well suited for studying these questions because the primary contributor to the nervous system's objective functionmetabolic energy expenditureis both well established and directly measurable. Decades of experiments using respiratory gas analysis have established that our preferred gait parametersfrom walking speed to step frequency and step widthminimize energetic cost (Atzler and Herbst, 1928;Donelan et al, 2001;Elftman, 1966;Minetti et al, 1993;Molen et al, 1972;Ralston, 1958;Umberger and Martin, 2007;Zarrugh et al, 1974). While some optimal motor control strategies may be established over relatively long periods of time, we recently discovered that the nervous system can re-optimize aspects of gait within minutes (Selinger et al, 2015).…”