A jogging stroller has to have a fixed front wheel if your intention is running, jogging or rollerblading.
If you run with a jogging stroller, you would need a fixed wheel. All you need is safety and stability. A stroller with a swivel wheel rattles and does not go smoothly.
I strongly recommend NOT to use a stroller with a front swivel wheel for jogging, running and not under any circumstances for rollerblading.
Let me tell you why: a front wheel should be fixed. No lock can guarantee that it will remain fixed at high speeds. The last thing that I would like to think about while rollerblading and pushing the stroller in front of me is the front wheel lock.
That is the same as to use a sport car for driving in the city center in the rush hour! Plastic joints and locks will not give you 100% guarantee of safety and stability. These factors are crucial. Bear in mind, the simpler the construction of the stroller, the more reliable and safer it is.
Even if you are not going to rollerblade or run with your stroller, you might face some kind of difficulties while walking as a swivel wheel might pull to the sides. It might happen especially at speedy walking pace. Besides, sandy beaches and snowy roads are difficult for a swivel wheel to conquer. You will have to lock it anyway.
I know some parents who run with a fixed swivel wheel. They say it is fine. But there is always much hassle of adjusting a stroller front wheel before it can go straight. If you are a serious runner, you should consider a running stroller with a fixed front wheel.