Adult Acquired Flatfoot

What is adult acquired flatfoot?

  • Adult acquired flat foot is a condition where the main arch of the foot loses its height giving the appearance that the foot sits flat on the floor.

How common is adult acquired flatfoot?

  • Posterior tibial tendon dysfunction is the most common cause of adult-acquired flatfoot.
  • It typically occurs in middle-aged women, particularly those with an elevated BMI, and is reported to occur in 3%-10% of this group (3).

Should I worry?

  • No
  • Symptomatic posterior tibial tendon dysfunction can be successfully treated non-surgically with physiotherapy (4).

Who is most likely to suffer from adult acquired flatfoot?

  • More common in women over 40.
  • Typically, those who have a high body mass index.
  • People who experience the condition have other likely medical conditions such as high blood pressure, diabetes and previous surgery in the area (3).

What are the common symptoms?

  • Flattened foot arch.
  • Often the pain will start along the instep of the foot, with pain developing behind the inner ankle bone and up the inner aspect of the leg.
  • A defining symptom is often an inability, or difficulty, to heel rise (go up on tiptoes).

What can I do?

  • If symptomatic, adult acquired flatfoot can generally be managed conservatively with specific advice and a personalised strengthening programme provided by a physiotherapist.
    • Lifestyle changes, such as losing weight.
    • Activity modification.
    • Exercise and physical activity to improve strength, health and fitness.

How long will it take to recover?

  • Rehabilitation time will vary between individuals and is dependent on the stage of the condition.
  • Generally, allowing for anything up to 4 months of rehabilitation would be recommended (2).

1. Introduction

Posterior tibialis tendon dysfunction is the most common cause of adult acquired flatfoot and is described in 4 stages (4).

The main function of the posterior tibialis muscle is to provide dynamic stabilisation of the inner arch of the foot. This initial dysfunction can lead to a cascade of worsening pathological events, therefore early diagnosis may be important in delaying or preventing worsening symptoms associated with this condition.


2. Signs & Symptoms

Often the pain will start along your instep of the foot with pain developing behind the inner ankle bone and up the inner aspect of your leg. You may have difficulty walking, with a generalised ache which may exacerbate throughout the day. A defining symptom is often an inability or difficulty to heel rise (go up on tiptoes) because your tibialis posterior tendon has a reduced capacity to perform this effectively. As symptoms and the condition deteriorate, inner ankle pain may be followed by pain on the outside of the ankle also, resulting from biomechanical changes.

3. Causes

The dysfunction of the posterior tibial tendon is a multifactorial process and can be difficult to attribute to a single cause. In many patients, there is a pre-existing flatfoot and many patients are also overweight, leading to increased stress on the tendon (1).

Episodes of previous trauma, corticosteroid injections, arthritis, neuromuscular conditions and diabetes all increase the risk of the development of the condition (1).


4. Risk Factors

This is not an exhaustive list. These factors could increase the likelihood of someone developing adult acquired flat foot. It does not mean everyone with these risk factors will develop symptoms.


5. Prevalence

Adult acquired flatfoot is more common in middle-aged adults, particularly females with an elevated BMI, and has a reported prevalence in the UK between 3%-10% (3).

6. Assessment & Diagnosis

Your physiotherapist will ask for a history of your symptoms, proceeded by carrying out a clinical examination so that a precise and timely diagnosis can be given to ensure the most effective treatment can be put in place immediately. Your physiotherapist will work closely with you to set individualised treatment goals and will regularly reassess you to measure your progress and make any necessary modifications in your treatment.

7. Self-Management

Upon receiving your diagnosis, your clinician will educate you on the condition so that you can understand how you can help manage your symptoms. The physiotherapist will suggest activity modification strategies that will allow you to remain functional without causing symptom exacerbation. Additionally, your physiotherapist can suggest ways to help reduce pain and recommendations on pharmaceuticals that can make you more comfortable, collaborating with your GP where needed.


8. Rehabilitation

Adult acquired flatfoot can generally be managed conservatively with specific advice and a personalised and progressive strengthening programme that your specialist physiotherapist can design to increase the strength of the soft tissues involved (2). Your physiotherapist will understand the structures that need strengthening and will tailor your exercises towards the activity-related and functional goals that will be established. You will regularly be reassessed to measure progress and we provide ongoing support and advice so that you can effectively and autonomously manage your symptoms.

9. Adult Acquired Flat Foot Rehabilitation Plans

Early Plan

This programme focuses on maintaining and restoring ROM (range of motion) with beginner strengthening exercises to the ankle and foot complex. All exercises should be kept to a tolerable level of pain. This should not exceed any more than 4/10 on your perceived pain scale.

Early Plan - Rating

Advanced Plan

This is the next progression. More focus is given to progressive loading of the foot and ankle to rebuild strength, stability, and proprioception (proprioception refers to the body’s ability to perceive its position in space). This should not exceed any more than 4/10 on your perceived pain scale.

Advanced Plan - Rating

10. Return to Sport/Normal life

For patients wanting to achieve a high level of function or return to sport, we would encourage a consultation with a physiotherapist as you will likely require further progression beyond the advanced rehabilitation stage. Before returning to your sport, a rehabilitation programme should incorporate plyometric-based exercises; this might include things like jumping and running exercises (5, 7).

As part of a comprehensive treatment approach, your musculoskeletal physiotherapist may also use a variety of other pain-relieving treatments to support symptom relief and recovery. Whilst recovering, you might benefit from a further assessment to ensure you are making progress and to establish an appropriate progression of treatment. Ongoing support and advice will allow you to self-manage and prevent future reoccurrence.

11. Other Treatment Options

The most common intervention with this condition is the use of orthotics. These can be off the shelf insoles that are used to create support for the arch of the foot or custom insoles that are made specifically for your feet. It is advised to use these in conjunction with a tailored exercise programme.


Book an Appointment

Please book an appointment with one of our physiotherapists if you think you are suffering from this condition and would like to find out more.

We have Pure Physiotherapy clinics across the country including Norwich, Bury St Edmunds, Manchester, Bolton, Southampton and Wakefield. Please view our clinics to find the closest physiotherapy clinic for you.


  1. Arain A, Harrington MC, Rosenbaum AJ. Adult Acquired Flatfoot. [Updated 2020 Aug 10]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2020 Jan-. Available from:
  2. Alvarez, R. G., Marini, A., Schmitt, C., & Saltzman, C. L. (2006). Stage I and II posterior tibial tendon dysfunction treated by a structured nonoperative management protocol: an orthosis and exercise programme. Foot & ankle international, 27(1), 2-8.
  3. Bubra PS, Keighley G, Rateesh S, Carmody D. Posterior tibial tendon dysfunction: an overlooked cause of foot deformity. J Family Med Prim Care. 2015;4(1):26-29. doi:10.4103/2249-4863.152245
  4. Kohls-Gatzoulis J, Woods B, Angel JC, Singh D. The prevalence of symptomatic posterior tibialis tendon dysfunction in women over the age of 40 in England. Foot Ankle Surg. 2009;15(2):75-81. doi: 10.1016/j.fas.2008.08.003. Epub 2008 Oct 1. PMID: 19410173.
  5. Nielsen MD, Dodson EE, Shadrick DL, Catanzariti AR, Mendicino RW, Malay DS. Nonoperative care for the treatment of adult-acquired flatfoot deformity. J Foot Ankle Surg. 2011 May-Jun;50(3):311-4. doi: 10.1053/j.jfas.2011.02.002. Epub 2011 Mar 31. PMID: 21458301.
  6. Vulcano, E., Deland, J. T., & Ellis, S. J. (2013). Approach and treatment of the adult acquired flatfoot deformity. Current reviews in musculoskeletal medicine, 6(4), 294-303.
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