Descriptions of the Aiki-taiso from Rod Kobayashi-Sensei:
6. Shomenuchi Ikkyo Undo
Take a natural step forward with your left foot. At the "One" count, move your hips forward and let your arms swing forward and upward from your fingertips. Do not overextend your arms. Let yourfingertips draw their natural arcs as you send them forward from your hips.
On the "Two" count, drop your fingertips downward. Do not swing your arms toward you intentionally or move your hips back before you drop your fingertips because they will hinder the effectiveness of the arm swing.
The upswing of the arms with Ki extended will protect you from an overhead strike from the front while the downswing can lead an attacker to become off balace and fall.
Repeat this exercise several times, then change feet and repeat with your right foot forward.