Triceps

Hi all, Lately I've realized that something feels amiss in my left arm as I play the piano. It doesn't feel like my arm is acting as one unit from the shoulder. My right arm feels very secure and I have this feeling that it's because the triceps and shoulder muscles in this arm are more developed. I know for a fact that these muscles in my left arm are nowhere near as strong. I was curious if anyone has had a similar feeling/experience. Also, would strengthening the tricep and shoulder possibly help to solve this problem? I was thinking a lot about it and as I said I think that my right arm uses the tricep when descending into the keys and playing a note. In my left arm I feel very little activity there and if anything I feel more activity in the forearm than upper arm. Thanks for any ideas you might have!