loon the blue badge give you entitlement to free buses as well as parking, and also applies to anyone who is driving you, so if you are not doing well with walking, especially with both legs hurting so much and dragging feeling, if you and DH go somewhere with him driving you can still use the badge. it is not for your use, it is for the use of whoever is using the car you are in, so you can transfer it to a friend's car if they are driving you. The rule is that the person driving the car has to either have you in the car, or be waiting to collect you, say for example they are coming to collect you from a hospital appointment but you are not already in the car, they can use it.
I don't necessarily think you have to have permanent disability as in never going to recover, but I think the terminology is it needs to be disabling for 12 months, or likely for 12 months, same as DLA/PIP - you need to have been experiencing the disabling problem for 3 months already with the likelihood of it continuing for 12 months or more. They normally issue 3 years at a time, but they will make an assumption that if you recover before the end of that time, you will send it back.
You apply to your local council, and will probably need to have an assessment - certainly that is how my local council do it. If you apply for PIP and are awarded the higher rate of mobility, your application for a blue badge is automatically awarded.
For those who are in work, or who are considering returning to work at any point - re what is termed a disability, our back conditions ARE protected under the Equality Act 2010, which superseded the Disability Discrimination Act 19somethingorother. Again, you need to have either been experiencing disability for 12 months already, or anticipate that you will be experiencing disability for 12 months or more. I think you need to have been experiencing the disability for 12 weeks already, but not completely sure of that. A disability is (not exact wording) a health condition that affects your day to day activities. It does not have to necessarily stop you or affect your job hugely. It is about how it affects your normal life within, and outside of the workplace, including travel to and from work, breaks at work, etc.
If you recover for the most part from your disability, but take time off on rare occasions, still need some adjustments, you are still protected as it will still be a disability, whatever level it affects you by at that time, as the protection is lifetime. This covers full recovery. So if you make a full recovery from disc prolapse after 12 months, then had a reprolapse 2 years later, you are immediately protected as a disability.