You might like to check your shoes, shoe insoles, walking working surface and duration and your own weight. Are the shoes right sized and have soft insoles? For example, Leather shoes with hard insoles can cause issue. If shoe insoles are hard and if you often keep walking or working in hard surface for long time, that causes strain to the leg muscle. If you are over weight, that also may add to the issue. You may consider the above and try light type of sports shoes that have soft insoles like dr scholls insoles.