Greetings akkar,
I tend to find that the area that is the weakest, or that I am holding tension in, shows up during the practice.
When one first starts riding a bicycle, s/he tends to overcompensate and use more energy and muscles than what's actually needed to perform the task until they gain skill/understanding of it.
As Master Lin would say, it's just your body doing its best with where its at, so thank it for helping you out all these years, then relax, breath into your lower dantian, and bring you focus back to your movement, breath, and visualization.
You can also sword finger the area through the day, clearing out the excess energy and giving back a healing message/energy.
Much Love, Shawn
Sometimes it starts shaking and when I stop standing the muscle throb.