Shoe Insole – Why my shoes don’t fit? (Part 4)

The shoe insole is located at the bottom of the shoe last and has to present certain measurement points from the plantar surface of the foot.

In our previous post “Why my shoes don’t fit? (Shoe last) we have learned that the shoe last has to represent three certain measurement points – joint, waist and instep – from your foot, only than a shoe can comfortably fit.
These three points are representing parts of the volume from your foot, but the shoe insole is presenting the width of your feet. We need to have a look to the bottom profile of the shoe last as well.


The blue line is our shoe insole and the vertical purple lines are representing the different bottom points of the last. Before I’ll explain, let’s spice this a little bit up, have a look at the next picture below, we are adding our foot profile here as well.


For our right foot we have taken the outer line(in green) and the foot surface (dotted line) and I have inserted another line in red, the joint-line.

Remember, in the first part of the series (shoe fitting), I have told you, that the actual length of the shoe is not really important for the fitting and here you can see why it is like this.

On every shoe last some extra allowance is been added on the toe. How much, that depends on the style of the shoe, in this case, it’s almost 25 mm or one inch. The minimum allowance for a shoe should be at least 10 mm. Now, if this shoe would have only a toe allowance of 10 mm, the toe shape of the insole would  certainly look different, but the shoe fitting would not change at all. But, if your foot is too long or too short then all the important lines of the insole profile would be in the wrong positions and will not match with your foot – the shoe can’t fit under any circumstances.
Let’s have a look at the inside and outside joints of the foot.( For clarification, these are the big bones on our foot, just behind the toes. In this picture the outside joint is not so prominent, don’t mind it. ) The outside line of the foot is of no concern to us here, but it’s the inside line, the profile of the feet (the dotted line), which matters here most.
As you can see, the insole (blue line) is touching the joints exactly, inside and outside, demonstrated by the new line I have added, the joint-line. Now this is very important for our shoe fitting.

The joint-line must connect the inside and outside joints of our foot.

If the joint-line would be too big and the joints would be outside of the insole, it would press our foot into the shoe. On the other hand, would the joint-line be too  small and wouldn’t touch the insole, the foot would slip forwards and the toes would bend forward for grip, which courses discomfort to the feet.

Finally, let’s go back to the toes of our foot. The mid- toe- line of the shoe last is very crucial for a comfortable fit. The big toe needs always to inside off the insole without having contact with the insole, because while walking, we are pressing our body weight to the front part of our foot and the big toe will bend to the outside by an average of 3-4 mm – with high heels even more. If there is no space in the shoe for the big toe to bend, it would press on the inside part of the shoe and this would put up lots of stress for the foot.

In our picture above, I’m not too happy with the insole shape, it should leave some more extra room for the big toe.

Waist and instep are important measurements too, but we are leaving them here out of the discussion for a moment. Only so much, they need to fit your shoe as well, if you feel any pressure or the shoe is loose at these points, please don’t go for it – it’s not meant to be yours!

For any questions or remarks, please leave your comment in the reply section. Continue reading with the next part about foot problems or download the free shoe guide  with measurement instructions
Andre Gerdes ( the shoe technician )

1 thought on “Shoe Insole – Why my shoes don’t fit? (Part 4)

  1. Thank you so much for this EBOOK.
    I am learning to become a shoe maker but want to start without the bad habits and also want to learn about the foot/last and how to eventually measure my clients feet for a perfect fit (possibly making my own lasts in the process?!?!?)- as just making shoes is not enough. Thank you again for this layman’s terms basic insight into a stupidily in-depth and what seems never ending learning of of this subject

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