When that happens, it's so important to seek quality care from a licensed physician and physical therapist. A physical therapist will help you with appropriate exercises and rehabilitation. They will use Physical Therapy Supplies and their knowledge of human anatomy to get you back in top form.
They work with your doctor to create a plan to get you back to your old self - or maybe a better (more mobile) version of your prior self.
If you know someone that has been injured, offer to help them find an appropriate health care provider. Offer to help with daily chores or getting to appointments. Having your help will better allow them to heal, and they'll be more apt to help you if you end up needing assistance.
Most of all, take care of your joints and muscles now. Get plenty of regular exercise, and don't push things too far too fast. Eat high quality meals, get plenty of fresh air and sunlight, and stay active with your family and friends. An ounce of prevention is really worth a pound of cure.