The stability and comfort when walking hands free has been addressed carefully using a combination of three different features.
The elastic (between the retraction housing and the attachment) works as a stabilizer. It is designed to absorb the sudden moves resulting from accelerating or decelerating when you start or stop walking as well as the up and down movements or turning left and right. (The elasticity strength is not enough to catapult the bag into the user. unless the bag is completely empty).
For the elastic to work in stabilizing the bag handle, it is important to have the Velcro loop attachment pretty tight on the bag handle to keep it in place from moving horizontally along the handle. We added silicon rubber on the back of the Velcro to provide a better grip. The bag handle may touch you only when you come to a complete stop depending on how fast you're going and how quickly you decelerate or stop.  Attaching the RetraStrap tightly to the corner of the handle nearest you helps guide the handle to your side and miss hitting you when you stop walking or decelerate.
the RetraStrap is adjustable so you can set it to the most comfortable length. Make sure it is not too short so it stays far enough from you when walking.
Running is not recommended while pulling the bag behind you hands free using the RetraStrap. always use caution.