Figure 6.5 shows the results of loosening the soil of a vegetable plot using hoes of two different types. In soft soil a swivel hoe is much more efficient than the ordinary chopping hoe but if the soil is hard and dry the two types are almost equally good.
A pleasant and not too strenuous walking pace is 75-110 steps per minute, with a length of pace between 0.5 and 0.75 m, but this is not the most efficient pace when the work performed is compared with the energy consumed. Figure 6.6 shows the efficiency of walking. expressed in terms of the energy consumed per kg/m of work performed.
From studies by Hettinger and Muller (1953) it appears that the most efficient walking speed is 4-5 km/h, reduced to 3-4 km/h in heavy shoes.