You will likely want to visit a general practice first as they would be better equipped to identifying if the problem is just your joints or if it is another issue that just shows symptoms in your joints. If you do need to see someone that specializes in joints then the general practitioner should be able to provide you with a referral.
A proctologist specializes in hemorrhoids.
Hematologist .
pathologist
what is the name of the kind of doctor who specializes in eye disease,i.e. macular degeneration?
Hematoligist
otolaryngologist
A Pulmonologist
An optometrist, ophthalmologist, or an optician.
cardiologist -evangeline chandran
Orthopedists and rheumatologists both treat joint conditions.
If the injury is to your foot you will want to seek out a podiatrist. That would be a doctor that specializes in foot injuries.
There isn't a specific doctor who specializes in this field of medicine. It will usually depend on what kind of musculoskeletal symptoms you are experiencing. Doctors who are D.O rather than M.D. have special training in the musculoskeletal system as well.