Investigation of Upper Extremity Functions in Patients With Rheumatoid Arthritis

This study is measuring upper limb function and arm strength in people with rheumatoid arthritis and comparing them to healthy people of similar age. This is an observational study — no new treatment is given — and aims to better understand how rheumatoid arthritis affects daily hand and arm activities. **You may be eligible if...** - You have been diagnosed with rheumatoid arthritis - You are between 18 and 75 years old - You are willing to voluntarily participate - Healthy volunteers in the same age range are also being recruited as a comparison group **You may NOT be eligible if...** - You have serious heart, lung, neurological, or musculoskeletal conditions that affect your physical function - You have participated in a structured exercise program in the past few months - You have cognitive difficulties that would prevent you from following instructions Talk to your doctor to see if this trial is right for you.