>>>>>>I would think that they the check in people can offer a wheel chair. Makes is much easier

That an EXCELLENT suggestion. On a recent Heathrow transit my mother, who has knee problems that cause pain, but could have walked, requested wheelchair assistance and it made a difficult shlep into 1st class treatment. Not only was there no strain for her, but they were wheeled through doors that others don't get to go through, and past queues where others had to wait. They (she and her husband) were, in effect whisked through a laborious transit in VIP style.

When I was a travel agent we would also order chairs for travellers who might even be mildly confused by where to go--it makes everything stressless--definitely consider requesting a chair (just call the airline in advance).