We practice kinhin, or walking practice, between sits.
At the end of a sit, the jikijitsu will strike a bell. You should then bring your hands into gassho and bow. After you rise from your bow, stand up and put your hands in gassho. The jikijitsu will strike a pair of clappers twice, and you will bow again. Continue to stand with your hands in gassho as the jikijitsu leads the kinhin line out of the zendo. Each person in the jikijitsu's line of cushions will fall in behind the jikijitsu in turn. The head of the second line will fall in behind the last person in the jikijitsu's line, and each person in his or her line will join in turn.
If your legs have fallen asleep during a sit and won't support you, just remain seated. After the kinhin line has left, stretch your legs until they come back to life, then join the kinhin line in your place.
As you join the kinhin line, lower your hands to your navel. Grasp your left thumb in your right hand and enclose the right hand with the fingers of the left. Walk naturally and mindfully. As you practice just sitting, practice just walking. Keep with the pace the jikijitsu sets; don't collide with the person in front of you or let too much space grow between you.
If you need to use the bathroom, you can bow briefly and step out of the kinhin line as it comes past the bathroom area. When you return, stand with your hands in gassho. When the line comes past you, bow briefly to the person who was behind you in line. He or she should return your bow and let you resume your place in line.
If you aren't staying for the next sit and need to leave the zendo entirely, bow and step out of line, and put on your shoes and leave discretely.
The jikijitsu will strike the clappers once to signal that kinhin is ending and the kinhin line is entering the zendo for the next sit. When you hear the clappers struck, place your hands in gassho. The jikijitsu will lead the people in his or her line to their places, and the leader of the other line with lead everyone else to their places on their side of the room. If everyone has remained in the correct position in line, this should be quick and easy, with no one needing to move past anyone else. All zendo procedures are designed to make everything work smoothly.
The jikijitsu will strike a bell. Bow and take up your zazen posture for the next sit.
Kinhin gives you a chance to stretch your legs between sits, but it is not "break time". It gives you the chance to continue your practice as you perform a more active task. Ultimately, your Zen practice will have to be integrated into your daily life. Kinhin is a transition stage. When you sit silently on the cushion, your body is relaxed and your mind is not distracted by demands from other people. The circumstances are ideal for Zen practice, but we can't sit on a cushion forever. As we walk silently and mindfully, we have the opportunity to continue our practice under just slightly more demanding circumstances. On a longer day of practice, we continue to eating mindfully and working mindfully before moving back into regular daily interaction. If you carry your practice with you through each stage, it becomes a habit, and it's easier to bring the mindfulness you find on the cushion into your daily life.