"Flat feet" are extremely common. Wether or not you actually have "flat feet" is a different story. I'm sure there are plenty of cases where insoles are genuinely required, but there are a lot more "therapists" selling you them at £80 a pair when you could do some rehab exercises and fix your pain for free!
Flat feet can be caused by a number of issues, but for now I'm just going to concentrate on hip weakness and it's effect on your arches. The amount of research into hip weakness and it's link to excessive pronation of the feet, flattening the arches.
How do hips affect foot position?!
The muscles of the hip depict the position of the thigh bone (femur). The largest muscle in the body is the main mover of the hip; the gluteus maximus. This along with the other hip muscles are responsible for hip abduction and external rotation.
If these muscles are weak, they fail to keep the femur in the correct position and alter the angle of the knee. The image below shows how this effects the foot more clearly:
As you can see, when the glute muscles are weak, the femur rotates inwards causing knee valgus (inward alignment of the knees). This causes the angle lower leg bones to alter and in turn overpronating the foot. This causes the arch of the foot to flatten, causing the "flat foot".
How do we fix your flat feet?
Hopefully you agree, you'd rather do some exercises every day for a while than wear insoles forever? Complete these exercises daily to strengthen your hips and fix that postural problem!
1. Glute band steps
You can get hold of some glute bands from Amazon for under £10. Use the band you find reasonably difficult to pull apart but that don't stop you moving correctly. Apply it round your ankles as shown in the image above and take a wide step to the side. Keep a good position and make sure your knees are driven outwards, over your foot. Don't let your knees bend inwards. Perform 12-15 steps in each direction, rest for 30-60s and repeat for a total of 3 sets.
2. Side-lying leg raises
No equipment needed for this exercise. Simply lie on your side with your top leg straight. Raise your leg up as high as comfortable with your knee straight. Lower it back down to around 2 inches off the ground and repeat. Again complete 12-15 raises on each leg continuously for 3 sets. There is no need to rest between sets on this one as one leg works while the other rests.
3. Glute bridge
The glute bridge is a good all round glute strengthening exercise. Again, no equipment is needed. Lie on the floor with your knees bent at around 90 degrees, ensuring your knees are in line with your feet. Drive your hips up and your heels into the ground to lift your bum off the floor. 3 sets of 12-15 reps with 30-60s rest in between sets.