Pes planus seldom produces any signs and symptoms. In cases when it does, pain is the most common complaint. In addition, the other symptoms include the following:

• Feet begin to ache after long hours of standing or after playing sports.
• Children often complain of pain in the ankle, foot and the lower leg [7].

• Plethora

  A diverse range of pre-fabricated and customised FOs were utilised and effectiveness measured through a plethora of outcomes. [ncbi.nlm.nih.gov]

• Lower Extremity Pain

  Alteration of foot biomechanics such as with pes planus, may play a role in the development of lower extremity pain with exercise 18. [ncbi.nlm.nih.gov]

• Foot Pain

  While improvement in terms of foot pain, foot function index and quality of life was observed in all the study groups (p< 0.05), the most improvement was observed in the group of patients treated with internal modification (p< 0.016). [ncbi.nlm.nih.gov]

  Pain may worsen with activity. Swelling along the inside of the ankle can also occur. When to see a doctor Talk to your doctor if you or your child has foot pain. [mayoclinic.org]

  Symptoms associated with fallen arches may include: Persistent foot pain not related to any other conditions Arch or heal pain that worsens with strenuous activities Visible swelling on the inside part of the ankle Diagnosing Pes Planus If the “wet foot [theshoesforme.com]

  […] of foot pain and foot problems such as:[1] Tibialis posterior dysfunction (because hyperpronation stretches this tendon). [patient.info]

• Anterior Knee Pain

  The goal of the study was to track the prevalence of pes planus in adolescents, and examine its associated risk to anterior knee pain and intermittent low back pain, respectively. [ncbi.nlm.nih.gov]

  Patellofemoral Pain Syndrome Your patella or "kneecap" is commonly affected due to its altered translation during movement. The rotational changes of the ankle and knee can push the kneecap in the wrong direction causing anterior knee pain. [boyner-clinic.com]

  Prevalence of anterior knee pain and pes planus in Israel defense force recruits. Mil Med. 2010;175(11):855-857. Google Scholar | Crossref | Medline | ISI 19. Levy, JC, Mizel, MS, Wilson, LS. [journals.sagepub.com]

  Patellofemoral Pain Syndrome Your patella or “kneecap” is commonly affected due to its altered translation during movement. The rotational changes of the ankle and knee can push the kneecap in the wrong direction causing anterior knee pain. [physioworks.com.au]

• Enthesopathy

  Myerson described two subsets of patients with PTT dysfunction. [37] One patient group was younger and had associated enthesopathies at multiple sites, a higher incidence of HLA-B27 positivity, and a significant family history for inflammatory disease [emedicine.com]

• Medial Tibial Stress Syndrome

  This can result in medial tibial stress syndrome : shin splints or tibia stress fractures. [physioworks.com.au]

  Medial Tibial Stress Syndrome or "Shin Splints" Due to the excessive pronation can cause the tibialis posterior or soleus muscle to apply altered stress to the inside aspect of the tibia. This can result in medial tibial stress. [boyner-clinic.com]

• Heel Swelling

  Some other subtle signs of problem can include: “Achy” or painful feet, especially around the heels Swelling in the inside bottom of the feet Increased difficulty standing or moving feet Leg and back pain Non-surgical Solutions Surgery is often the last [theshoesforme.com]

Diagnosis of pes planus is made by a preliminary physical examination of the foot. The formation of arch upon standing on the toes will determine the type of flat foot present. For example, if an arch is formed when the individual stands on the toes then the condition is known as flexible foot. However, when no such arch in formed then the condition is referred to as rigid flat foot.
Individuals with flexible foot require no further tests or treatment. But, those diagnosed with rigid flat feet have to undergo the following diagnostic procedures:

• Plain X-ray and weight bearing X-ray of the affected foot to further understand the condition [8]. 
• Imaging studies such as CT scan of the bones and MRI of the tendons of the foot are also required to occur at definite diagnosis.

• Joint Space Narrowing

  and joint space narrowing of the MTP1 joint (chi2 = 12.7, p = 0.013). [ncbi.nlm.nih.gov]

  On MR images, bone marrow edema, abnormal articular orientation, and joint space narrowing were frequently identified adjacent to the abnormal joint. [doi.org]

• HLA-B27

  Myerson described two subsets of patients with PTT dysfunction. [37] One patient group was younger and had associated enthesopathies at multiple sites, a higher incidence of HLA-B27 positivity, and a significant family history for inflammatory disease [emedicine.com]

Children and toddlers affected by pes planus do not actually require any treatment if they are not experiencing any pain or discomfort while walking and even otherwise [9]. However, when the condition causes pain then the following methods are available:

• A foot support known as orthotic is inserted into the shoes that provides support to the feet. In certain cases, doctors also recommend special shoes with heels to be tailor made that need to be worn until the arch forms naturally.
• Certain lifestyle changes such as regular exercise to lose weight may be recommended. Affected individuals are advised to avoid standing or walking for longer durations.
• Medications may be prescribed to relieve the pain and discomfort.
• Surgical intervention is usually the last resort and is employed only when other treatment methods are not effective enough or the condition is causing great discomfort to the individual [10]. This involves, creating an arch in the foot, fusion of the bones, and repairing the tendons.

Majority of the cases of pes planus do not need any treatment as individuals do not experience any symptoms. In conditions when they experience pain, several treatment methods are employed to relieve pain and discomfort. Some cases of flat foot may require surgical intervention to correct the problem. Individuals benefit from the method and the prognosis is usually favorable. Pes planus from tendon rupture may require prompt surgical intervention, delay in the intervention may result into a poor prognostic outcome [6].

Complications

Pes planus by itself can rarely cause any serious complications. However, when the condition requires surgery then post-surgical complications include the following:

• Infection 
• The bones that were fused do not heal
• Pain persists even after the procedure
• Foot deformity does not get corrected
• Loss of ankle movement

Pes planus results when the tendons in the foot are loose. It is a common condition for infants and toddlers as the tendons take some time to tighten and form an arch. Other causative factors that give rise to pes planus include the following:

• Heredity 
• Illnesses or injury to the legs that damage the tendons
• Diseases such as muscular dystrophy and cerebral palsy can also give rise to pes planus
• Posterior tibial tendon insufficiency [1]
• Obesity [2]
• Traumatic rupture of foot ligaments [3]
• Other disease conditions such as rheumatoid arthritis and diabetes can cause the arch to flatten in individuals who otherwise did not have pes planus

Pes planus is a common condition affecting about 25% of the American population. In majority of the cases, the condition is reversible and can get corrected if treatment is initiated at right time. Acquired pes planus is fairly common in middle-aged women who are obese [4].

Under normal circumstances, the tendons of the foot develop in a way to form an arch. In condition of pes planus, the tendons do not form a longitudinal arch. However, if such a condition occurs normally then it gets corrected by itself as the child grows up. The tendons tighten and gradually form an arch. In some cases, it takes several years for the arch to develop and in some the arch does not develop at all. There are basically 3 types of pes planus namely: Flexible flat foot, short Achilles tendon and posterior tibial tendon dysfunction with interosseous ligament involvement [5].

Pes planus cannot be prevented since it is more of a heredity condition. However, the onset of secondary complications can be prevented by appropriately following the treatment recommended by a podiatrist.

Pes planus, commonly referred to as flat foot, is a condition wherein the foot does not form the normal arch in the standing position. It a common condition affecting millions of individuals across the globe. Such a kind of condition is normally identified in infants and toddlers.

Pes planus can get corrected by the time the child is 3 years old. Flat foot may be present in one or both the feet. There are no associated symptoms and pes planus can seldom lead to any serious consequences.

Definition

Pes planus also known as flat foot is a condition characterized by absence of an arch in the foot in the standing position. This condition is a normal phenomenon in infants and toddlers and usually gets corrected as the child grows. With growing age, the tendons tighten and gradually form an arch. It has been estimated that about 20 – 25% of the population fall prey to such a condition. Pes planus seldom gives rise to serious secondary conditions.

Cause

Heredity is one of the common causes of pes planus. In addition, other conditions such as diseases and injury to the feet are also known to give rise to flat foot.

Symptoms

In majority of the cases, flat foot has no accompanying signs or symptoms. But, certain types of pes planus such as rigid flat feet may cause pain and discomfort while walking.

Diagnosis

Affected individuals are made to stand on their toes and the examination is carried out. If an arch is formed in this position, it implies that the individual is suffering from flexible flat foot. Such a condition does not require any further diagnosis. If no arch is formed then further tests such as CT scan, MRI and X-ray of the feet is carried out for differential diagnosis.

Treatment

Individuals are given foot support to be worn inside the shoes that provide support to the foot while walking. Medications may also be prescribed if there is pain and inflammation. Surgery is employed to fuse the bones together or lengthen the tendons if they are too short to form an arch.

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2. Funk DA, Cass JR, Johnson KA. Acquired adult flat foot secondary to posterior tibial-tendon pathology. J Bone Joint Surg Am. Jan 1986; 68(1):95-102.
3. Levy JC, Mizel MS, and Wilson LS, et al. Incidence of foot and ankle injuries in West Point cadets with pes planus compared to the general cadet population. Foot Ankle Int. Dec 2006; 27(12):1060-4.
4. Myerson M, ed. Posterior tibial tendon insufficiency. Current Therapy in Foot and Ankle Surgery. St Louis, Mo: Mosby-Year Book; 1993:123-35.
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7. Pinney SJ, Lin SS. Current concept review: acquired adult flatfoot deformity. Foot Ankle Int. Jan 2006; 27(1):66-75.
8. Kong A, Van Der Vliet A. Imaging of tibialis posterior dysfunction. Br J Radiol. Oct 2008; 81(970):826-36.
9. Rome K, Ashford RL, Evans A. Non-surgical interventions for paediatric pes planus. Cochrane Database Syst Rev. Jul 7 2010; CD006311.
10. Key JA. Partial rupture of the tendon of the posterior tibial muscle. J Bone Joint Surg Am. Oct 1953; 35-A (4):1006-8.