Fig. 1
From: Limb phase flexibility in walking: a test case in the squirrel monkey (Saimiri sciureus)
The phase wheel. Limb phase values from 0 to 100% (where 0% = 100%) can be represented as a circular continuum (a circular representation of the y-axis of a classic Hildebrand diagram). The circle can be segmented into four quadrants, each running between a simultaneous footfall pattern—a pace or a trot (black circle), and an evenly spaced footfall pattern—what Hildebrand [13] called the singlefoot (gray circle). The circle can be divided into halves vertically and horizontally by sequence and couplets respectively in which LS: lateral sequence, DS: diagonal sequence, LC: lateral couplet, DC: diagonal couplet; the shaded gray area is that of the DSLC gaits which appear to be uncommon in nature, see text for details