The accelerometer will sense most of the normal steps regardless, even if you keep your hands in the pocket or you hold a bag or a soda can, so don't worry about that. One thing you should know is that all the wrist based pedometers try to filter for movements of your hands while you are actually not walking (driving, typing, etc...). The undesirable side effect is that they tend not to register any step while your pushing a cart or a stroller. As far as I know all wrist based devices have this issue, so you just have to live with it or work around it (I tend to push my kids in the stroller using only one hand, same with the cart at the grocery store).
I've had it count accurately when I've held the dogs leash in the hand with watch on it or with my hands in my pocket so I don't think your arm needs to swing completely freely.
Also phones do a pretty good job while in your pocket so there obviously doesn't need to be large motions to register steps.
When you step, there is a high frequency distinct signal that the accelerometer will register. It will use this possibly along with other signals like arm swings to distinguish a step.
The main signal is that 'thud' when you step. You can recreate this signal by making a hammer fist and banging it on your other hand or a table and watch your step count increase - don't use this to cheat your step count or silence you move bar though :)
Driving over a long distance can also add some steps to your step count.
I drove my RV 600km, which added approx. 10.000 steps for that day, and I was definitely not walking around that much, just sitting behind the wheel. Same happened on the next day and on the return leg of this journey, so that could not have been a glitch.
Any thoughts or similar experiences?
