Though the fever in chikungunya infection typically lasts a few days to a couple of weeks, some patients have prolonged fatigue lasting several weeks as with other arboviral fevers like Dengue, etc. In addition, some patients report incapacitating joint pain, or arthritis, which may last for weeks, months or rarely even years after the other symptoms have subsided. Nearly all cases recover over time.
In your case, back stiffness related to physical exertion (in a 46 years old person) could also reflect lack of physical exercise and fitness, and a visit to your doctor for a physical evaluation would be advisable.