Uncontrolled supination on the left forearm and hand

Hi doctor, I am a 35 year old man. Lately, I have been experiencing uncontrollable supination problems in my left forearm and hand. When I straighten the arm either straight forward (90 degrees, palm facing downward) or straight down (0 degrees, palm facing backward), uncontrolled supination will occur on the left forearm with my left hand. If I want to stop the uncontrolled movement by turning in the opposite direction (pronation) or just by holding the position, I will feel strong resistance and tension in the forearm to wrist, and can not stop the uncontrolled movement of supination (the feeling is like rotate and squeezing wet cloth in 2 different directions). The uncontrolled supination movement will continue to rotate and put pressure on the forearm and hand until I “fold” the forearm towards the elbow (elbow flexion?) and press lightly on the Median nerve or place nearby it, then the uncontrolled supination will only and my hand and forearm movement becomes free again. It will happen again if I straighten my forearms again.

For doctor’s knowledge, last week I went to the klinik kesihatan for an examination, but the doctor there mentioned that this was an ergonomic problem and poor blood circulation, but I was a right hand user and my left hand was affected. I was only given painkillers/anti-inflammatory at that time because my wrist was sore and there was a little inflammation as a result of my early attempt to stop uncontrolled movements before the visit. A week after, my condition did not see much improved yet.

Can the doctor provide some idea on what is happened to my left forearm? And can the doctor suggest which specialist can do an examination for my condition? Because if I visit klinik kesihatan again, possibly they will only give me another batch of NSAID or maybe nerve suppressant.

Looking forward from your reply soon.