1st time cramping After SPOrt...Funny...Ouch!!!

Today after school I have badminton selection...Unfortunately,,the hall were used by the drama ppl...then all the badminton's player play at the area beside the hall...I start play without warm-up... bt when reach home , my backbone cramped and its feeling was terrible...OUCH!!!... It was my 1st time cramping after sport all the time....Wakaka!!!...