Arch height is one of the parameters that indicate your chances of developing issues related to the shape of your foot and your posture.
A very high or low arch height could put you at risk of some musculoskeletal disorders. However, most people are not aware of these risk factors due to which they fail to identify the root causes of the pain and discomfort they experience while walking, sitting, or performing routine physical activities.
The lack of awareness about the importance of measuring arch height is one of the reasons why the musculoskeletal issues arising due to them continue to persist or worsen in most cases.
A simple change in the footwear is all that is needed to relieve or avoid these symptoms.
If you are suffering from pain and discomfort in your legs, soles, ankles, thighs, or back, read on to check whether a high or low arch height could be responsible for the same. We will discuss what arch height means, the implications of having an abnormal arch height, and what you can do to avoid any complications.
What is an arch height?
An arch height is the measure of the characteristic shape and structure of your foot. Measuring arch height is considered a superior and reliable way to characterize the foot structure and shape in order to ascertain the causes of pain in the legs and back.
Measuring the arch height also involves comparing these characteristics between the standing and sitting positions.
The best way to check your foot arch is to dip your soles in colored liquid and get an imprint of the same on a paper.
Here are the different types of foot arches based on the arch heights:
Normal or medium arch height
If the middle part of the arch is at least half-filled (as shown by the imprint of your soles dipped in colored liquid), it means you have a normal or medium arch height. A medium arch can support your body weight naturally. It can also allow your foot to roll in (pronate) easily while under a reasonable load.
People with a medium arch height are usually advised to wear shoes with straight or semi-curved lasts and firm midsoles. The ‘last’ here refers to the shape of the sole. It also indicates the shape of the footprint around which your shoe can be built to provide improved rear-foot stability.
A flat arch
In case your footprint resembles the shape of a complete foot, you are likely to have a low arch height or a flat arch.
This means your footprint would show the complete outline of your sole without any space that should otherwise be created due to the arch of the foot at the middle and inner part of the sole.
In this case, your foot may not have the ability to roll in or pronate easily while you are walking or running resulting in a higher risk of injuries and missed steps.
The lower arch height may also contribute to muscle strain and joint issues.
These problems can be avoided by wearing a walking shoe having a straight last with better motion control that can help to stabilize your feet more effectively.
If your footprint shows a very little of the soles with a larger portion of the middle and inner parts missing from it, you are likely to have a high arch foot.
The high arch may contribute to strain on the muscles and joints. It suggests that a significant portion of your soles does not touch the ground while you are walking.
This implies that the shock-absorbing capacity of your foot is reduced due to the lack of adequate contact of the sole to the floor. As a result, your foot would not absorb shocks well, especially while you are performing impact and jumping activities.
This can put you at a higher risk of falls and injuries.
The reduced shock-absorbing capacity may also create more strain on the muscles of the legs and back as the shock would transit through the soles to the other tissues of the body more easily.
This is one of the reasons why men and women with a high arch often develop pain in the knees, hips, and back. They may also experience moderate to severe pain and stiffness in the muscles, which may limit their physical activities.
The adverse effects of having a high arch could be avoided by using shoes with a cushioning to compensate for the lack of shock absorption. Additionally, a curved last could also help in these cases. 
Now that we have had a look at the different types of arch heights, let us check how to measure the arch height so that you can choose the appropriate footwear to avoid the problems associated with them.
How to measure arch height?
Here is a step-by-step method you can follow to measure your arch height:
- To measure the arch height, the person should first sit on a chair placing his feet on the ground.
- Then, place two boards under the heels and the heads of the metatarsal to ensure maximum possible collapse of the foot arch.
The metatarsals are the thin and long bones in the soles of the feet that extend from the ankle to the base of the toes. There are 5 metatarsals in each foot each of them leading to the base of the respective toe.
The head of the metatarsal is the part that is close to the base of the small bones called the proximal phalanx in the toes.
- Once the person is positioned in this manner, the right and left jig is used to measure the length of the foot as well as the truncated foot length.
The truncated foot length refers to the foot length from the first metatarsophalangeal joint (the joint between the head of the metatarsal or the proximal phalanx of the respective toe) to the heel.
- The arch height can now be measured as half of the foot length using a free-falling bar. The measurement is recorded for both legs.
- The patient is then asked to stand.
- The measurement of the length of the foot, as well as the truncated foot length, is taken in the same manner for both the feet in the standing position.
These measurements can help you calculate the arch height index in standing and sitting positions, arch drop, and arch rigidity index for both feet. The geometry-based measurements for arch height are repeatable as given below:
- AHI (Arch Height Index) = Arch height at the half Foot length divided by the truncated foot length in sitting position
- ARI (Arch Rigidity Index) = Standing AHI divided by sitting AHI
- AD (Arch Drop) = Arch height at the half foot length in the sitting position minus arch height in the standing position
Based on your arch height, you can choose appropriate footwear to avoid any consequences related to a low or high foot arch.
Application of the measurement of arch height
Most people do not give much thought to their arch height. However, knowing that you have a low or high arch height could really be helpful when it comes to understanding how your body mechanics work.
Once you have figured out if you have high arches or the flattest of the feet, or even if you are somewhere in between with a medium arch height, you can know how your feet work, and how they affect the movements of the rest of your body.
This will allow you to determine what you can do to take care of these issues. Let us have a look at what it means to have a high or low arch foot and how to avoid the musculoskeletal issues linked to them. 
What does it mean to have a high arch height?
A higher arch height implies the arch of your foot has a slightly curved area between the ball of the foot and the heel. People with unusually high arches can develop a range of problems from occasional mild pain to even permanent structural changes.
While some people are naturally born with high arch height, some may develop it later in life as a symptom of an underlying disorder such as Charcot-Marie-tooth disease, cerebral palsy, spinal cord tumors, muscular dystrophy, polio, spina bifida, and stroke.
Your family history, physical examination, and the review of your footwear and walking pattern can help to reveal the possible causes of the high arch foot.
In some cases, X-rays, electromyography, and nerve conduction velocity may be recommended to identify the underlying causes so that proper treatment can be administered.
The common complications linked to high arch height include plantar fasciitis and metatarsalgia.
Patients with a high arch foot are prone to develop plantar fasciitis that occurs due to the inflammation of the band of a ligament called the plantar fascia that connects the heel to the toes and supports the arches.
Metatarsalgia is a painful condition caused due to the inflammation in the ball of the foot. The symptoms of metatarsalgia often improve after taking rest and become worse after walking, standing, or exercising. Flexing the foot may worsen the pain.
The claw toes is another condition common in patients with a high arch. Claw toe refers to the toes that take on the claw-like shape causing digging down of the soles into the shoes. It often affects the four smaller toes.
Hammer toe and ankle and foot instabilities are other common issues linked to the high arch. 
How to avoid the complications linked to high arch?
- Patients with a high arch may use orthotic devices that are designed to provide artificial support. These devices can be worn in the shoes to provide extra cushioning and stability.
- Foot pads made of silicone and foam can also be worn in the shoes to relieve pain and pressure.
- Night splints can be used while sleeping for stretching the arch of the foot and calf in order to relieve plantar fasciitis.
What does it mean to have a low arch height?
People with a low arch height or flat feet either have no arch in their feet or have one that is too low.
The footprint of these individuals usually reveals a gap under the inner part of the foot as the arch raises against the ground.
Patients with flat feet need treatment only if they develop pain and discomfort that indicate any underlying disorder. It should be noted that some people with a high arch do not experience any symptoms.
Some patients may complain of pain and stiffness in the arch of the foot, ankles, calf, hip, knee, lower back, and lower legs.
The common causes of flat feet include genetic factors, weak arches, ankle or foot injury, rheumatoid arthritis, rupture or damage to the posterior tibial tendon, and cerebral palsy.
How to relieve the symptoms of a low arch?
- A physical therapist may recommend exercises to relieve the symptoms caused due to flat feet. These exercises are also aimed at improving the strength and flexibility of the ankles and feet. 
- Heel cord stretching is another treatment that helps to stretch the posterior calf muscles and Achilles tendon and relieves the symptoms of flat foot.
Measuring the arch height in both the feet will help you determine the possible causes of musculoskeletal symptoms you are suffering from.
Regular exercises and the use of the most appropriate footwear can help to relieve the symptoms of a high arch or low arch and help you live a healthy and active life without the risk of complications linked to the abnormal arch heights.