I have this pain on my upper back and recently pain over my left hand (over triceps), I am a programmer so I spend a lot of time before a computer.

Overuse Injury. This sounds like an overuse issue related to posture, as you suggest in your question. You may try OTC anti-inflammatories such as Motrin or Aleve (naproxen) in the short term, but a physical therapy evaluation may provide useful tips on preventive posture as well as strengthening and stretching exercises to prevent further discomfort or injury.