Why remove the original shoe liner?
A full-length orthotic occupies space inside the shoe. Removing a removable liner can create more depth and allow the orthotic to sit directly on the base of the footwear.
What happens if two full-length insoles are stacked?
- toe room can be reduced;
- the heel may sit too high;
- the shoe may become difficult to fasten;
- pressure can develop over the top of the foot;
- the heel may slip;
- the orthotic may sit at the wrong height.
Does the original liner always need to come out?
No. Some footwear has enough depth to accommodate an additional thin insert, and many three-quarter-length orthotics are designed to sit over an existing liner.
The decision depends on the device, the shoe and the available space.
What if the liner is glued in?
Do not automatically pull out a fixed liner. It may form part of the shoe construction.
Instead, check whether the shoe has enough depth or choose footwear with a removable liner.
How should the orthotic sit after the liner is removed?
It should lie flat, remain stable and allow the heel to sit fully back in the shoe.
The edges should not curl or rock on an uneven base.
Can removing the liner make the shoe too loose?
Yes. A very thin orthotic may occupy less volume than the original liner.
The final setup should still hold the foot securely and should not allow excessive movement.
What about three-quarter-length orthotics?
These often leave the front of the shoe liner in place and can therefore work in footwear where a full-length replacement would take up too much toe-box space.
What is the simplest fit check?
- Place the orthotic flat in the shoe.
- Put on the socks normally worn with the footwear.
- Seat the heel fully back.
- Fasten the shoe normally.
- Check toe room, heel hold and pressure over the instep.
- Walk briefly and make sure the orthotic does not slide.
When should you seek help?
If removing the liner still leaves the shoe too tight, or if the orthotic rocks or changes position, a different shoe or professional fitting may be needed.
