You should be riding with your shoulders dropped and relaxed and a slight bend at your elbows. Your arms shouldn't be taking too much of your weight with locked out straight elbows or tight shoulders. A trick I read is that you should be able to waggle your elbows in and out while you ride - if not then something is locked when it shouldn't be.
Also your back should be straight, not hunched. One way to do this is to conciously push your lower back forward to straighten out your spine. Not sure if this is part of the problem but it might be.
You should be riding with your shoulders dropped and relaxed and a slight bend at your elbows. Your arms shouldn't be taking too much of your weight with locked out straight elbows or tight shoulders. A trick I read is that you should be able to waggle your elbows in and out while you ride - if not then something is locked when it shouldn't be.
Also your back should be straight, not hunched. One way to do this is to conciously push your lower back forward to straighten out your spine. Not sure if this is part of the problem but it might be.