adapted by C. Higgs from E. Ayappa, Normal Human Locomotion Part 1: Basic Concepts and Terminology Journal of Prosthetics and Orthotics, V. 9, No. 1, 1997 http://www.oandp.org/jpo/library/1997_01_010.asp

Stance phase

Stance phase is the period during which a limb bears weight. Single limb stance (or single limb support) occurs when the contralateral limb is off the ground. Double support is when both feet are touching the ground simultaneously. Young children spend much of their gait cycle in double support, as they grow the time spent in single support increases. In three-year olds single-limb stance lasts for about 35% of the gait cycle. In seven-year olds, this is closer to 38% and, in adults, single-limb support lasts 39% of the entire cycle.

Swing phase

Swing phase occurs when the limb swings forward to prepare for the next step. The swing phase of the right leg coincides with single stance of the left leg and vice versa.