I Want to Learn More About Chakras

I visited a reiki massage therapist and during the draining massage they told me my solar plexus was blocked (knotted)

I carry a lot of tension in my shoulders they said and have a build up of lactic acid, I was getting stiff necks as a child also and in adult hood, back ache to the point where I could not move.

Is this all caused by emotional problems?

How to unblock them?