The generalized response is likely that it depends. Certainly most current management theory I've seen speaks to the answers here about the benefits of moving the body, and the approach that knowledge work (including software development) is best as salaried, results oriented work, where it shouldn't matter what your observed behavior is (as long as it is not offensive) as long as you do the work well and on time. I don't think anyone could honestly average out the totality of manager/company opinions on whether best practices are actually followed widely. I'd hope so, but it's hard to say with any certainty.
But let me point out a couple useful areas of management, policy and potential thoughts for legislation:
Breaks - Salaried vs. Hourly
I've noticed the trend that breaks are considered differently depending on whether you are salaried or hourly. There tends to be a lot more regimentation in any corporate policy over protecting the rights of hourly workers. In some offices, I've seen breaks mandated for them and as the US legislation covers it, their breaks are covered as part of their pay (where lunch is not). Often salaried guidelines are not as clear, given that the hours are far more flexible, although in cases where the employee's time is billed to a client, this can also be quite regimented.
Hours worked?
Usually with salaried folks, I have seen managers generally take notes of entry and exit times (if this is a traditional office environment). You like to know you can find people for a certain number of hours a day. I often don't see that most managers care much about breaks, but if they are long or if your are hard to find for hours on end, the excuse "I was taking a walk" may not cut it. In essence, 5-10 is a lot easier to handle than 30-60 minutes - particularly if we are talking twice a day. Even a 20 minute break, two times a day, is going to add up to more than half an hour (a common unit of time charging), and the manager may expect that you be around longer than the typical 8 hours if this isn't a team norm.
That said, if you are a wizzing along, meeting the same expectation as anyone else, and doing it in the typical hours a day (including breaks), then I have trouble seeing the average manager having an issue here.
Accomodation
At least in US law, the word "accomodation" is a word treated with a certain amount of caution. If you have a variety of health issues, it can be highly advisable that you get in a few brisk walks a day. I'd go so far (from a personal perspective, no medical expertise here) to say that if you qualify as human, a quick walking break will do you good... so getting a doctor's note even, to cover it, should be possible for many if not all people.
It never hurts to clear any accomodation with your manager, though. Getting up and walking around randomly could come off as weird in some cultures, but going to your manager and saying "hey, I stiffen up both physically and mentally if I don't get in a brisk walk every 2 hours - I'll do it anywhere you like, but I have to do it to stay productive" isn't out of line.
Disruption
Looking from another angle, the common reason management objects to walking around is usually the disruption. Some folks like walking, some folks like as few distractions as possible - and the two can be mutually exclusive in some environments. Be aware as you walk about those around you and set a tone by limiting or avoiding conversation.
At least in places I've worked, it's not a walker that gets the flack, but someone strolling the halls looking for a juicy conversation instead of getting to work that gets labeled as the slacker. But if timing is bad and you're always off having a conversation when management walks in, you could be setting a tone that you would prefer to prevent.
Also, sadly, some buildings are just hard to walk in - in which case, a walk outside of the team area may be in order.
Performance
In most places I've worked, it's really about performance. But a talk about performance can quickly lead to a talk about walking around alot. A manager has to point out issues in performance, when an employee isn't getting work done. And it's not always easy to observe the actual problem when there's a big performance gap. Walking to think and walking out of distraction are hard to differentiate. But walking vs. pounding on a keyboard is easy.
Whether the feedback "don't walk around" is given in your performance review or a fellow coworker's - it's good to ask the speaker "why". The answer is likely to be that there's a claim that work isn't getting done... which is the real problem.
For the most part, in software environments where the work was highly valued, I've seen tolerance for all sorts of goofy behavior (and a walk is hardly goofy) and as long as the performance is good and sustainable.