Final answer:
Double support is the phase during the gait cycle where both feet are in contact with the ground, accounting for approximately 10-30% of the cycle. It provides balance and stability during walking.
Step-by-step explanation:
The double support phase is approximately 10-30% of the gait cycle. In the context of a normal gait pattern, during walking at a comfortable speed, double support refers to the period where both feet are in contact with the ground simultaneously. This phase is crucial for maintaining balance and stability as the body's weight shifts from one leg to the other. There are two double support phases within a single cycle: once after the heel strike of the initial limb and before the toe-off of the contralateral limb, and once after the heel strike of the contralateral limb before the toe-off of the initial limb.