Gamekeeper's thumb is when you hurt your thumb that makes it hard for you to hold things or move it properly. It usually happens when you get injured on the inside of your thumb near the base of your thumb. This can happen when your thumb gets twisted or pulled suddenly, like when you fall down or catch something really heavy.
Your thumb has a special ligament that helps keep it in place so you can use it properly. When you hurt your thumb, this ligament may get stretched or torn. This can make it hard to use your thumb like you normally do. It may hurt when you try to grip something or move your thumb around.
If you think you might have gamekeeper's thumb, it's important to see a doctor. They can check to see if your ligament is injured and give you the right treatment to help you feel better. This may include wearing a special brace or splint, doing exercises to strengthen your thumb, or in more severe cases, surgery to repair the ligament.