Miner was exiting desk chair and tripped over lunchbox below the desk causing miner to fall to the floor. Miner hit left knee first, then left arm, then head on the wall. Miner refused medical attention at the time of incident(12/18/2020). Miner later determined on 04/07/2021 that medical care was needed. Miner's first date of lost time was 04/09/2021.