Grandson’s Flat feet

My feet have caused me many problems, which I think stemmed from childhood. I kept being told to walk straight, but I didn't know any other way than putting one foot in from of the other. The shoe repairer kept telling my mum I walked on the inside of my feet!! Again I was told off.

Life might have been easier if these problems had been corrected when I was a child

I was 8 when my mother noticed.
Yes, I think you should mention it as he will be given exercises to do to help.
However, I must say that exercises didn't help me because of the type of problem I have, and I had orthotics, which werent so good in those days.
I refused to wear them as a teenager and teetered around in high heels which made it worse. It's so much easier for a boy to always wear sensible shoes.

It does cause me issues with my hips but didn't until well into adulthood

Yes, the hips and knees get used to being in a certain position and, if you then start wearing orthotics later in life, it can put them back to where they should be but that can be painful.

Starblaze, you jogged my memory. We used to buy trainers for pronation (flat feet), they are readily available. However, like the others say, you can’t push it too much, it’s his parents’ decision. Our son was/is extremely flat footed. The specialist said they didn’t come any flatter!

I have flat feet, all my joints are too flexible. I wouldn't pressure parents, they might not like it.

It does cause me issues with my hips but didn't until well into adulthood

Good arch support won't hurt, just buy him some nice trainers lol

My son has flat feet. I took him to the doctor when he was a little boy and the doctor’s attitude was “he’s fine, he can walk okay “.

I took him to see my podiatrist as a private patient.She took a very different attitude. Because she was NHS registered, she was able to refer him to the podiatrist at the hospital. They made shoe inserts for him to provide some sort arch under his feet. He returned at intervals as his feet grew, gave him exercises to do and recommended ankle boots rather than shoes to support his ankles in a more upright position. We were advised that not treating his feet would result in back and knee pain in later years.

He is tall and does suffer a little with his back, particularly when he has been on his feet all day.He wasn’t very conscientious about doing the exercises. I encouraged him to walk with his feet straight rather than at “10 to 2 “. Apparently, feet splaying is all to do with compensating for short tendons (I think) and the exercises are to stretch them. He naturally walks with his feet straight now.
The shoe inserts weren’t ideal as he always felt like he was walking out of his shoes. The little toad was resistant to having ankle boots. Now he is an adult, I see he has some ankle boots and he has visited podiatrists of his own volition.
He was advised also that regarding exercise to keep fit, jogging and distance running were not ideal for him because of his feet.

If not causing pain or discomfort flat feet do not need any treatment.

You don't need to do anything if you or your child have flat feet that aren't causing any problems.
Taken from the NHS website:

Flat feet:

don't usually cause any problems
shouldn't stop you doing any activities, including sports
are rarely a sign of anything serious
In children, flat feet usually last until they're about 6 years of age.

But buffy if your daughter says she’s never noticed it that has to really be the end if it
Running ‘on his heels with one foot splayed out’ doesn’t really sound how I thought (no experience here) flat feet would appear running, but unless his parents are concerned, you ve mentioned it the once, and that’s all you can do

My grown up GD has flat feet it’s never stopped her doing anything. If your GS is doing all the things kids do without problems I wouldn’t draw his attention to it. Of course if it was causing problems then his GP would be the way to go.

My husband has flat feet and it's never caused any issues. If your daughter is concerned about it she could check with a podiatrist.