Is My Repetitive Thumb Bending And Arm Flinging Until They Crack A Sign Of A Medical Issue Or Just An Unusual Habit?

i keep bending my thumb unintentionally until i hear a crack sound (mostly my right hand thumb repeatedly) i also keep flinging my arms in the forward position until it cracks.. (both repeatedly) i ve never seen others do this, not even once.. i even googled it and didn t get an answer that fits my situation.. Is something wrong with me or do i just have a rare thing??