Hello,
This may help some of you. I woke up one morning in March of 2018 with a stiff neck from what i thought to be sleeping wrong. I went about my day cause this was not the first stiff neck i ever had. But when i went to the gym that night, while attempting to warm up with dumbbell shoulder presses , my left arm went straight up and my right arm would not budge. These were 40lb dumbbells. I usually warm up with those and go up to 70lbs by the end of the workout. I forced 5 reps out of my right arm but knew something was wrong. I thought it was tendinitis or something, being that i played baseball and had it before . But next workout same thing on chest day i could not bench 135lbs, i could not even do 5 push ups. I then started to notice my right tricep wasting away. I went to an onsite doctor at work, he tested all my movements and said you should be fine. I kept working out everyday lifting what i could which was nothing. It is now November and i have went from not being able to bench alot or do much weight on my triceps to now seeing my tricep gaining muscle and benched 275 once . I get strong every week but my right is still alot weaker then my left. It is coming back i never went to the doctor or got checked. I just googled and found many people with the same issue. My bicep and tricep are still pretty soft but getting bigger. Its been 9 months and i have seen alot of progress, i read somewhere it takes a full 2 years to get back to 100%. I feel i will be there in about 18 months. One thing i did was i kept working out the entire time. I never stopped which may be why i am ahead of the curve. Good luck to you all.