Is it realistic to use a cane/crutches to beat the shit out of someone/run someone over with a chair/rollator/etc? I would personally do it but I wonder if it's different for those who use different aids. (If the context matters, it's between two characters who don't really care about larger ramifications in a kind of typical dumb teen delinquent way, they have a vitriolic relationship where they get on but express their emotions by brawling in the parking lot and such things)
Most mobility aides are not structurally sound enough to be used as a weapon, meaning they would bend, dent, or otherwise break if used to strike someone or something. And if you are reliant on your mobility aid to get around, you wouldn't want to risk damaging it by using it as a weapon in a fight. You might need to use it to run away, and it's very hard to run away on dented crutches. Plus, if it's damaged, you will need to replace it, and replacing your mobility aid can be a real pain and very expensive. Unless they have one of those fancy canes that are specifically reinforced for combat purposes (which are hundreds, if not thousands, of dollars and far heavier than normal canes,) they'll either break their mobility aid or they won't put enough force behind the swing to do damage. It would be a desperate last resort measure.
(Plus, assuming your character can swing a cane or crutch hard enough to do actual damage, it would be very easy to accidentally put someone in the hospital or even the morgue. You aim an aluminium pole at someone's temple or neck and you run the risk of killing them even if you don't put a lot of force behind the swing. Same problem with the face. Hit them in the gut and you can damage organs, at the chest and you can accidentally snap ribs or stop the heart. Aim it at a joint and you could severely mess up said joint. Aim it at the back and you run the risk of messing up organs or the spinal cord. Aim it at any bone beyond something like the femur (trust me, hollow aluminium pole is not going to do more than bruise the femur unless you're Superman, you will break the cane or crutch long before you will so much as crack the femur) and you could cause a serious break, like an open or comminuted fracture. Even aiming it at a major blood vessel like the femoral could cause catastrophic internal bleeding or haemorrhaging. That's another reason it's a last resort measure, because if you can do actual damage, you're likely to do a lot of it. Remember, a mobility aid is still a metal pole. You would break it if you put enough force behind it to cause damage, but there is a potential for serious harm there that you don't want to take unless it's life-or-death.)
You could roll someone over with a rollator or wheelchair. I have seen people run over other people's feet using the wheels of their wheelchairs (one famous example is that Stephen Hawking used to run over the feet of people he did not like with his wheelchair.) You wouldn't be able to run over someone's body with it, that's far too uneven a terrain, but running over someone's foot or hand is plausible. Unlikely to do any real damage, but plausible and at least likely to hurt due to the number of nerves in the hand and foot.
Using a mobility aid as a weapon is a last resort measure- I've seen people state that they would sooner look for an improvised weapon such as a plank of wood before they considered using their cane or crutches to whack someone. If you're writing it as a last resort measure, yes, it can be realistic. But very few people are going to swing at someone's head with a cane if they're just in a little spat or are just sparring. Plus, using this trope just reinforces the idea that disabled people's mobility aids are threats. A cane or crutch is already seen by cops as a potential bludgeon, a prosthetic leg as a potential bomb, a wheelchair as somewhere you can hide weapons. Even though the use of mobility aids as weapons is a very rare occurrence, people assume it is more common, so everyone using a mobility aid is treated as a potential threat or even as if they've already done something wrong when they haven't. And if you attack someone with a mobility aid, it's seen by the law as less of a crime because "they have a weapon and just didn't use it." Best not to perpetuate the stereotype as it does have real-world consequences.
I'd give them some other form of weapons if you would like them to engage in armed combat.
