Fig 1.
Grinding tools, grinding position, and grinding movements used in the experiment.
Saddle quern (A) and rotary quern (B) used in the experiment. Kneeling position used during experimental grinding (C, D). To-and-fro movement used during experimental saddle quern grinding (E) and clockwise and anticlockwise rotary movements used during rotary quern grinding (F).
Fig 2.
Muscle activation during cereal grinding in athletes and nonathletes.
Maximum muscle activation (maxEMG, upper row) and mean muscle activity (meanEMG, lower row) in athletes (black squares) and nonathletes (white circles) during saddle quern (left column), clockwise rotary quern (middle column), and anticlockwise rotary quern (right column) grinding. Markers and whiskers indicate the means and 95% confidence intervals of the means, respectively. Significant difference between athletes and nonathletes (p < 0.05) is indicated by an asterisk. See Table 1 for abbreviations of muscles.
Table 1.
Maximum muscle activation (maxEMG, %MVC).
Table 2.
Mean muscle activation (meanEMG, %MVC).
Table 3.
Total activity of all measured muscles adjusted to PCSA (Summed meanEMGPCSA, %MVC cm2) in the eight- and four-muscle models in nonathletes.
Fig 3.
Results are shown for athletes (yellow, dashed line) and nonathletes (blue, solid line) during saddle quern (left column), clockwise rotary quern (middle column), and anticlockwise rotary quern (right column) grinding. Darker lines and colored areas indicate the means and ± standard deviations, respectively. See Table 1 for abbreviations of muscles.
Fig 4.
Mean muscle activity adjusted for PCSA of the muscles (meanEMGPCSA) in nonathletes.
Results are shown for saddle quern (left), clockwise rotary quern (middle), and anticlockwise rotary quern (right) grinding. Markers and whiskers indicate the means and 95% confidence intervals of the means, respectively. See Table 1 for abbreviations of muscles.