Pes Planus – What Causes Flat Feet?

There are two distinct types of ‘pes planus’ – the medical name for flat feet. Either rigid or flexible, with flexible being the most common.
Both types appear ‘flat’ when standing, with no or little sign of a medial long arch in the feet. But when lying down with no weight on the feet, or when tip-toeing, an arch does reappear with flexible flat feet. An arch can be formed in this case with the right custom corrective orthotic treatment.
It is completely normal for babies and toddlers to have flat feet, because their bones are still forming, muscles toning and fatty padding covers their feet. As they grow and start to walk, an arch usually starts to form as they toddle, with arches taken shape between 4-6 years old. This is why we recommend that parents bring their children to a Podiatrist for a foot screening as they start school. This is the perfect age to detect any issues, especially with arch formation and to correct it if required. Corrective orthotics can be easily worn within their school and sports shoes and early intervention will reduce the likelihood if longer term issues in adulthood such as osteoarthritis.
It is common for one foot to have less of an arch than the other.

Pes Planus, or ‘flat feet’ can be congenital or develop later in life
The arch of the foot is an extremely important structure that enables our feet, ankles, legs and hips to function efficiently. Think of your foot as a bridge, with the arch being the springy bridge that connects the front and back of your foot.
Signs of Pes Planus
Patients attend the specialist foot clinic, Dubai Podiatry Centre, on Sheikh Zayed Road if they have noticed themselves that they have feet that look ‘flat’, or are worried about their children appearing to have flat feet. Sometimes, there is pain also, generally where the arch should be.
What Causes Pes Planus?
Flat feet can be caused by a variety of reasons.
In children, it is quite normal for babies and toddlers to have flat, chubby feet. As they walk and grow, an arch should spontaneously form normally by the time they are around 4-5 years old. This is the perfect time to have their feet checked for any issues by the Podiatrists at Dubai Podiatry Centre, who also carry out annual school screenings.
If an arch hasn’t formed, this may be due to:
• Loose ligaments in the foot not holding the bones in correct alignment (genetic)
• Neurological (e.g. polio, cerebral palsy)
• Bony developmental issues, such as tarsal coalition
Pes Planus is very common, with a least 20-30% of people having it. Most have ‘flexible’ flat feet and no pain. However, a significant number do experience pain, not just in the feet but to the ankle joints, knees, hips and lower back experiencing abnormal stress loads.
If the arch has started to fall during adulthood, it is called ‘acquired’ flat foot (as opposed to genetic, or something they inherited from one or both parents).
Acquired flat feet can be caused by:
• Tibialis posterior tendon dysfunction
• Tear of the spring ligament
• Tibilais anterior rupture
• Neuropathy caused by diabetes, polio or other illness
• Wear and tear to the foot and ankle joints, caused by arthritis, sprains or fractures
Contributory factors:
• Unsupportive footwear (flip flops, ballet flats encourage the foot to over-pronate to hold the footwear on)
• High heels – limiting toe movement
• Tight Achilles tendons / calf muscles
• Bony abnormalities e.g. ankle equinus
• Congenital ligament laxity e.g. Down’s Syndrome, Marfan’s Syndrome
• Muscle imbalances causing over-pronation e.g. hip abductor weakness, Genu Valgum
• Hereditary – “It is extremely common for me to see a child patient with flat feet, and either mum or dad also has the same issue,” says Mrs Champlin
• Hyper or over-pronation of the sub-talar joint.
• During pregnancy due to the release of hormones causing ligament laxity
• Increased bodyweight
• Foot or ankle trauma such as sprain or fracture
Pes Planus Symptoms
Many flat feet do not cause pain. We usually recommend treating flat feet if it is new, getting worse, causing pain or linked to another complaint (such as hallux valgus). You should see your Podiatrist if you (or your child) experience the following:
• Foot, ankle, knee or hip pain
• Tiring easily when walking or running
• Clumsy gait / tripping
Your Podiatrist will be assessing whether the pes planus is bilateral (both feet) or in one foot, worse in one foot than the other, has been present since childhood or recently started, if there is any pain in the feet, legs, hips or back, family history and any associated illness or factors such as diabetes.
Your Podiatrist will carry out an extensive biomechanical lower limb assessment, which will identify any associated issues with heel cord tightening, tight calf muscles, and range of other associated foot problems that can be caused or worsened by pes planus. These include:
• Hallux valgus (bunions) caused by flat feet putting too much pressure through the big toe joint when weight bearing
• Metatarsal stress fractures – same reason as above
• Plantar fasciitis – due to too much strain on the plantar fascia connecting the heel bone to the forefoot
• Tibilais posterior dysfunction.
Now we know more about flat feet – why you might be born with it or develop it later in life. Read on now for how to correct it.