I am unable to straighten my right arm, or flex it. Extending the arm, or pulling the forearm up towards me, causes pain in the forearm, the bicep, and the muscles at the back of the elbow. Ibuprofen reduces the pain. Movement is limited; unable to lift a cup to my mouth. The condition has existed for some years, but in the past week it has become much worse, for no apparent reason.
Hello, Have you ever taken an MRI brain and cervical spine? Because the symptoms are mixed up here with Higher motor functions and peripheral nervous system. If you have taken one what was the reports indicating? It makes a sense to rule out between the Higher motor functions and peripheral nervous system functions. Since you have pain in forearm and also limited movements arm muscles like biceps and triceps I will advise for physiotherapy sessions. Like transcutaneous nerve stimulation therapy for pain in the forearm and improving the muscle elastic property for biceps and triceps. ROM exercise for the elbow to have freedom of movement for maximum ability to be achieved.  Exercises include - static biceps, static triceps, static deltoid, status neck exercise, static forearm exercise etc. Check out online you will find samples of same. Let me know after a week to ten days, so we can add some proper exercise regimen. Jay In Chat Doctor.