Bad shocks
Your brain.
Bad shocks, ball joints bad, tires out of balance. More then likely shocks.
Out of alignment or bad shocks or struts
Worn shocks, -very common.
Something that causes an involuntary action
tardive dyskinesia
check shocks
your shocks or your brake pads are probly loose. You need to check them out. If that's not it then take it to a mechanic.
It is caused by involuntary muscle contractions.
it is a problem in the nervous system
Gmtjh