Flat feet are one of the most over-treated and under-understood conditions in foot care. We use objective gait analysis and diagnostic imaging to determine whether yours actually need intervention — and what kind.
Flat feet (pes planus) describes a foot posture where the medial longitudinal arch sits lower than typical during standing or walking. The heel often tilts outward (rearfoot eversion) and the forefoot may splay or abduct. This is an extremely common foot type — estimates suggest 20–30% of the adult population have some degree of flat foot posture.
The critical point that many clinics miss: flat feet are a foot shape, not a diagnosis. Having flat feet doesn't automatically mean you have a problem. Many elite athletes — including marathon runners, rugby players, and sprinters — perform at the highest level with flat foot posture. The question isn't whether your feet are flat, but whether that foot posture is contributing to symptoms or functional limitations.
There are two fundamentally different types, and the distinction drives every treatment decision:
Flexible flat feet — The arch appears low or absent during weight-bearing but reforms when you stand on tiptoe or when the foot is examined in a non-weight-bearing position. The joints are mobile, the foot functions through its range, and the arch can be restored with muscle activation. This is the most common type and frequently requires no treatment at all if asymptomatic.
Rigid flat feet — The arch is absent regardless of position — in standing, on tiptoe, and when examined off the ground. This indicates structural change in the bones or joints, often from tarsal coalition (a congenital bony or cartilaginous bridge between tarsal bones), previous fracture, advanced posterior tibial tendon dysfunction, or degenerative joint disease. Rigid flat feet more commonly cause symptoms and are more likely to require intervention.
A third important category is adult-acquired flat foot (posterior tibial tendon dysfunction, or PTTD). This develops in adulthood — typically affecting one foot — when the posterior tibial tendon progressively weakens and fails to support the arch. It's staged from I (tendon inflammation with maintained arch) through to IV (rigid deformity with ankle involvement). Early identification and treatment of PTTD is crucial because it's progressive — what starts as tendon pain can become irreversible structural deformity if left untreated.
If you have flexible flat feet with no pain, no functional limitation, and no progressive change, treatment is unlikely to offer meaningful benefit.
Children under the age of 6 almost universally have flat-appearing feet because the fat pad under the arch hasn't yet thinned and the arch is still developing — this is normal development, not pathology.
In adults, asymptomatic flat feet that have been stable for years typically need monitoring rather than intervention.
We are honest about this. Not every patient who walks through our door with flat feet needs orthotics, exercises, or treatment. Our job is to give you an accurate assessment and honest advice — even when that advice is "your feet are fine."
This is the centrepiece of our flat foot assessment. In-floor pressure plates capture exactly how forces distribute through your feet during walking — not just a static snapshot, but the dynamic reality of how your foot loads with every step.
This data transforms orthotic prescription from opinion-based to data-driven. Instead of looking at a static footprint and prescribing a generic arch support, we can see exactly which phase of gait needs correction and target orthotic features accordingly.
For flat feet with pain along the medial ankle, we use ultrasound to assess the posterior tibial tendon directly. A healthy PT tendon appears as a bright, fibrillar structure approximately twice the diameter of the adjacent flexor digitorum longus tendon. In PTTD, the tendon becomes thickened, hypoechoic (darker), and may show partial tearing, peritendinous fluid, or increased vascularity on Power Doppler.
Ultrasound also identifies spring ligament damage (a key stabiliser of the medial arch), tibialis posterior tenosynovitis, and accessory navicular syndrome — all conditions that present alongside or mimic flat foot symptoms.
We assess the Foot Posture Index (FPI-6), a validated 6-item scoring system that quantifies foot posture objectively on a scale from -12 (highly supinated) to +12 (highly pronated).
Treatment depends entirely on diagnosis. Asymptomatic flexible flat feet need nothing. Symptomatic flat feet need targeted intervention. PTTD needs stage-specific management.
Designed and manufactured using SLS 3D printing via Réalta Labs. For flexible flat feet: medial heel skive, calibrated arch fill, forefoot posting. For rigid flat feet: accommodation over correction. For PTTD: higher medial flanges, deeper heel cups, UCBL-style devices.
For PTTD stages I–II. Structured progressive loading from seated resisted inversion through to single-leg balance and heel raise work. Individualised based on clinical stage, ultrasound findings, and functional capacity.
Restricted ankle dorsiflexion is one of the most common drivers of compensatory pronation. Structured gastrocnemius and soleus stretching combined with ankle joint mobilisation addresses this root cause.
Weakness in the hip external rotators (particularly gluteus medius) allows internal rotation during stance, driving secondary pronation. We assess and address the entire kinetic chain.
For associated conditions such as plantar fasciitis or posterior tibial tendinopathy that haven't responded to initial conservative treatment.
For PTTD stages III–IV or when conservative management fails after 6–12 months. Options include tendon transfer, calcaneal osteotomy, or arthrodesis. We continue managing orthotic needs post-surgically.
Parents frequently bring children for assessment of flat feet, often concerned by advice from relatives, school nurses, or shoe shop staff. It's important to understand that flat feet in children under 6 are almost universally normal — the medial arch develops progressively between ages 3 and 10, and early intervention with orthotics in this age group has not been shown to influence long-term arch development.
We recommend assessment for children when there is:
Our paediatric assessment is thorough but gentle, and we are upfront with parents about what does and doesn't require treatment. We'd rather reassure a worried parent than prescribe unnecessary orthotics for a developing foot.
Symptoms, activity levels, and previous treatment.
Foot Posture Index scoring, single-leg heel raise testing, Jack's test, muscle strength, and lower limb alignment.
Detailed force distribution mapping — the most important objective measure for flat foot assessment.
Where indicated: posterior tibial tendon, plantar fascia, and spring ligament assessment.
Clear explanation with images and data shown to you. A tailored treatment plan — including honest advice if treatment isn't necessary.
Total appointment time: approximately 45–60 minutes. No GP referral needed.
Outcomes depend on the specific diagnosis:
Symptomatic flexible flat feet managed with orthotics and exercise — most patients report significant improvement within 4–8 weeks. Orthotics manage the mechanical problem; ongoing use during aggravating activities is typically recommended.
PTTD stage I (tendinitis) — full recovery expected with 8–12 weeks of structured rehabilitation combined with orthotic support.
PTTD stage II (tendon degeneration with flexible deformity) — management is typically long-term. Orthotics and strengthening can stabilise the condition and significantly reduce symptoms, but the tendon may not return to full normal function.
PTTD stages III–IV — conservative management aims to reduce pain and improve function, but structural correction usually requires surgery.
We monitor progress with repeat pressure plate analysis and ultrasound scanning, tracking objective changes in gait patterns, tendon structure, and functional capacity alongside your symptom reports.
Paul McMullan BSc(Hons) MSc FRCPSGlasg MRCPod — Lead clinician with nearly 15 years of specialist experience in biomechanical assessment and orthotic prescription. Currently completing an MSc in Podiatric Sports Medicine at Queen Mary University of London. Fellow of the Royal College of Physicians and Surgeons of Glasgow. Extensive experience with complex flat foot presentations including adult-acquired flat foot and post-surgical management.
Darren Costello BSc(Hons) MSc PGCert — MSc Sports and Exercise Medicine, postgraduate certificate from Brunel University in lower limb musculoskeletal assessment. Specialist interest in gait analysis and progressive rehabilitation for tendon pathology.
Objective data, not guesswork.
To assess tendon pathology without a separate referral.
Manufactured using 3D printing technology.
We'll tell you if your flat feet don't need treatment.
Assessing hip, knee, and ankle alongside foot posture.
HCPC registration and Royal College memberships.
Common questions about Flat Feet at Lower Limb Clinic.
Get Flat Feet at our clinic, conveniently located in East Belfast
385 Lisburn Road, BT9 7EP
373 Ormeau Road, BT7 3GP
1 Shimna Road, BT33 0AS
We serve patients from across Belfast and Northern Ireland including East Belfast, South Belfast, Lisburn, Bangor, Holywood, Newtownards, Dundonald, Carryduff, Hillsborough, and Comber.
Get Flat Feet at our clinic, conveniently located in East Belfast
385 Lisburn Road, BT9 7EP
373 Ormeau Road, BT7 3GP
1 Shimna Road, BT33 0AS
We serve patients from across Belfast and Northern Ireland including East Belfast, South Belfast, Lisburn, Bangor, Holywood, Newtownards, Dundonald, Carryduff, Hillsborough, and Comber.