What is Age Related Flat Foot?
Age-related flat foot, or adult-acquired flatfoot deformity (AAFD), is a condition where the arch of a person’s foot collapses over time. Unlike the flexible flat feet seen in many children, AAFD develops later in life, typically affecting individuals in their 40s and beyond, with a higher prevalence in women. This progressive flattening is most commonly attributed to the failure of the posterior tibial tendon (PTT), a vital structure that runs along the inside of the ankle and is responsible for supporting the foot's arch. As this tendon and the surrounding ligaments weaken with age, the arch loses its support and collapses.
The Role of the Posterior Tibial Tendon
To understand age-related flat foot, it is crucial to know the function of the posterior tibial tendon. This tendon acts like a pulley system, connecting the calf muscle to the bones on the inside of the foot and helping to create and maintain the arch. With every step, the PTT helps lift the arch and support the foot. Years of repetitive use and strain from walking, running, and other weight-bearing activities can cause this tendon to become inflamed, stretched, and eventually worn down.
When the PTT loses its strength, the foot can no longer maintain its proper alignment. The arch sags, and the heel bone may begin to shift outward, a process known as overpronation. This misalignment, in turn, places excessive strain on other foot structures and can lead to a cascade of related problems.
Common Causes and Risk Factors
While age is the primary factor, several conditions and lifestyle choices can increase the risk of developing AAFD:
- Aging: The natural wear and tear on tendons and ligaments over decades is a leading cause.
- Obesity: Excess body weight places significantly more pressure on the foot's arches and the PTT, accelerating its degeneration.
- Chronic Diseases: Conditions such as diabetes, high blood pressure, and rheumatoid arthritis can increase the risk of tendon damage and inflammation.
- Repetitive Stress: High-impact sports like running, basketball, or soccer can put excessive strain on the foot's supportive structures.
- Genetics: A predisposition to foot structure issues can be inherited, meaning those with a family history of flat feet may be more susceptible.
Symptoms and Progression
Age-related flat foot typically progresses in stages, with symptoms worsening over time if left untreated.
Stage 1: Mild Inflammation
- Pain and swelling along the inside of the ankle and foot, where the PTT is located.
- Pain often increases with activity but subsides with rest.
- The arch may appear normal and flexible.
Stage 2: Arch Collapse
- The foot's arch visibly collapses, but the foot remains flexible.
- Difficulty or inability to perform a single-leg heel raise, a test where you stand on one foot and try to raise your heel.
- The heel may begin to turn outward, and the forefoot points outward, a phenomenon sometimes called the "too many toes" sign when viewed from behind.
Stage 3: Fixed Deformity
- The foot becomes rigid and the deformity is no longer flexible.
- Pain may shift to the outside of the ankle as the collapsing heel pinches against bones.
- Early stages of arthritis can begin to develop in the subtalar joint.
Stage 4: Ankle Involvement
- The most severe stage, characterized by deformity in both the foot and the ankle joint.
- Significant arthritis develops, and the ankle joint may be misaligned.
Impact on Overall Health
The effects of AAFD are not limited to the feet. When the foot's foundation is compromised, it creates a domino effect up the kinetic chain, impacting the ankles, knees, hips, and lower back. Poor alignment can lead to joint pain, muscle strain, and altered gait patterns that increase the risk of falls and other injuries. Other foot problems, like bunions and plantar fasciitis, are also more common in individuals with flat feet.
Comparison of Flat Foot Types
| Feature | Congenital Flat Foot | Adult-Acquired Flat Foot (AAFD) |
|---|---|---|
| Onset | Present from birth or early childhood. | Develops later in life, typically after age 40. |
| Cause | Lack of arch development, often genetic or due to hypermobility. | Degeneration of the posterior tibial tendon and supportive ligaments. |
| Flexibility | Often flexible, meaning an arch can appear when not bearing weight. | Starts flexible in early stages but progresses to rigid in later stages. |
| Symptomatic | Often painless, with symptoms only developing later in life. | Can be painful from the onset, with pain worsening over time. |
| Progression | Typically doesn't worsen significantly, though it can progress in adults. | A progressive condition that will worsen without treatment. |
Treatment Options
Treatment for age-related flat foot depends on the stage and severity of the condition and is typically managed by a podiatrist or orthopedic specialist.
Conservative (Non-Surgical) Treatments
- Orthotic Devices: Custom-molded or over-the-counter arch supports can provide crucial support, realign the foot, and relieve pressure.
- Physical Therapy: Targeted exercises can strengthen the posterior tibial tendon, calf muscles, and other foot-stabilizing muscles. Stretches for a tight Achilles tendon are also beneficial.
- Supportive Footwear: Wearing shoes with good arch support and a firm heel counter helps control foot mechanics and reduce strain.
- Activity Modification: Reducing high-impact activities like running and jumping and opting for low-impact exercises (e.g., swimming, cycling) can reduce stress on the feet.
- Medication and Ice: Nonsteroidal anti-inflammatory drugs (NSAIDs) can help manage pain and inflammation, while icing can reduce swelling.
- Immobilization: In acute cases, a walking boot may be used to rest the tendon and allow it to heal.
Surgical Treatments
Surgery is typically considered when conservative therapies fail to provide relief, the deformity is advanced, or arthritis is present. Surgical procedures vary widely and can include:
- Tendon repair or transfer to reconstruct the failing PTT.
- Osteotomy, or cutting and repositioning bones, to correct the alignment.
- Joint fusion (arthrodesis) for severe, rigid deformities to provide stability and pain relief, though this can result in a stiffer foot.
Conclusion
What is age related flat foot? It is a progressive and often painful condition resulting from the weakening of the foot's supportive structures, primarily the posterior tibial tendon. While age is a significant risk factor, other elements like obesity and chronic diseases can contribute. Recognizing the symptoms in their early stages is vital for effective management with conservative treatments like orthotics, physical therapy, and supportive footwear. Left untreated, the condition can lead to significant pain, deformity, and issues in the ankles, knees, and back. Consulting a foot and ankle specialist is the best course of action to diagnose the condition and create a personalized treatment plan to maintain mobility and reduce discomfort. For more information on PTTD and its symptoms, OrthoInfo offers a detailed resource on the topic.
