Shoe trouble

So I went on a hike last weekend and the trek was rocky and there was no clear path. I mostly had to navigate through large bushes and plants. Once I started my climb down I felt a sharp pain on my toe whenever I took a step down. I felt that it was because my toe kept pushing on to the tip of my shoe and it was truly painful. I really just wanted to remove my shoe halfway down. My shoe is a decathalon hiking pair. Any idea as to why this happened ? Is it because my shoe is too small for my feet size ?