deslomar
to break one's back
des-
un-, dis-
+
loma
hill, ridge
+
-ar
verb suffix
Deslomar literally means to un-hill0 (des-0) the ridge1 (loma1) of your back, which idiomatically translates to to break one's back. The -ar2 ending makes it a verb2.
verb
  1. to break one's back
    To break or injure someone's back
    No te deslomarás si levantas el peso correctamente. // You won't break your back if you lift the weight correctly.