Cubital Tunnel Syndrome is most common in people who spend long periods of time with their elbows bent, such as when holding a telephone to the head. Flexing the elbow while the arm is pressed against a hard surface, such as leaning against the edge of a table, is a significant risk factor.
That is a tricky one! And not as simple and straight forward as muscle repetitive strain and tendon irritation. Nerve entrapment of the Ulnar nerve can take place anywhere along the neck, shoulders, and arms and can have a downstream deleterious effect. There may even be a 'subluxation' of the nerve when it pops out of its groove in the elbow.
Compression of the nerve area at the back (medial) part of the elbow is not a good idea because it may aggravate the nerve further. And never massage a nerve!
The only way that Armaid-use could help is if you massage the inner (flexor) muscles in the middle belly or distal (closer to the wrist) parts of the forearm flexor muscle (not at the muscle attachments at the elbow) and release any tension and tightness found in those flexor muscle areas. The tight flexor muscle attachments at the elbow could be causing your problem.
As I said, there are several ways and even multiple areas (pressure points) that could be affecting this condition... you could even have a cyst or a growth compressing the nerve as well.
There are so many potential factors involved that I would suggest consulting with a medical professional who is familiar with this condition to ask for accurate assessment and treatment advice.
Massage may be of help with some of the cause of the problem as I mentioned, but it could easily be a further aggravation if not done properly.
I hope this gives you some insight into your problem, sorry it's not as straight forward as tendinitis.
All the Best, Terry