Vibration for pain?

Lizz • 💙5.5.19&4.15.22💙

So I woke up this morning with a really painful knot in my lower back on my right side, like near my hip. I was on my feet almost all day yesterday and then fell into a coma like sleep so I’m assuming I just slept in a funky position. Anyways one of the physical therapists at my job saw me rubbing my back all morning and lent me a little hand held vibrating massager like this one

I’ve been sitting with it between me and my chair all morning and it’s helping the pain sooo much. The only thing is every time I turn it on the baby starts to kick like crazy! I’m sure he can feel it, or some of it. (I’m 35+2). I just wish I could know if he’s kicking because he likes it or if he’s kicking because it’s bothering him. Anyone else use vibration for pain late in your third?