The first thing you should do is to identify the cause of the problem, and then go for physical therapy, medication, or surgery. The causes of the inextensibility of hand joints include tenosynovitis, trauma, osteoarthritis, etc. It is recommended to find out the causes of the disease before the treatment, and carry out targeted treatment. 1. Tenosynovitis: If patients work on their hands for a long time, such as operating computers and knitting, which causes excessive friction between tendons and tendon sheaths, tenosynovitis is likely to occur, and with the aggravation of the condition, there will be obvious stiffness of the joints, which will result in the inability to straighten the joints of the hands. 2. Trauma: If the patient’s hand is hit by an external impact, the violent impact will easily cause hand fracture, and the patient will easily be unable to straighten the hand joints, which is usually accompanied by obvious pain. 3. Osteoarthritis: Due to the damage of articular cartilage caused by various factors, osteoarthritis is easily caused, which leads to joint stiffness, pain, and limited activities. Causes of hand joints not straight more reasons, may also be related to osteophytes, gout, rheumatoid arthritis and other factors, if the symptoms continue to have no relief, it is recommended to go to the hospital in a timely manner to find out the cause of the disease, by the doctor targeted treatment.