Hi, thanks for writing to HCM.
From the description, I feel that all your symptoms are related to the ISCHEMIA
of muscles and nerves in the forearm and hand caused by the constricting pressure applied to the arm for 20 minutes.
I think, this is going to resolve spontaneously with 4-6 weeks.
In the meantime, you are advised to regularly perform movements of all the joints in the upper limb so that they will not develop any contractures
leading to deformities.
Hope this information is helpful. Good day