When your arches fall, the tendon that holds up the inner curve of your foot gradually stretches, weakens, and loses its ability to support the arch. The arch flattens toward the ground, your ankle rolls inward, and the alignment of your entire lower leg shifts. This isn’t a sudden snap. For most people, it’s a slow progression that starts with mild pain and swelling and, left unaddressed, can reshape the foot permanently and cause problems all the way up to the knees and lower back.
What Actually Collapses
The arch of your foot is held in place primarily by a tendon that runs from your calf muscle, wraps behind the inner ankle bone, and attaches to bones on the underside of your foot. This tendon acts like a stirrup, pulling the arch upward every time you take a step. When it becomes damaged or inflamed, it gradually lengthens and can no longer hold the arch in position. The bones of the midfoot sag downward, and the heel tilts outward.
Several ligaments and smaller muscles also support the arch, but once the main tendon starts to fail, these structures take on more stress than they were designed for. Over time, they stretch too, and the collapse accelerates. The condition is most common in women over 40, with reported rates above 3% in that group and over 10% in all adults past age 65. The typical person who develops it is a woman in her 50s or 60s carrying extra body weight, since elevated BMI increases the mechanical load on the tendon with every step.
How It Progresses
Fallen arches don’t happen overnight. Clinicians recognize four stages, and understanding them helps you gauge where you might be.
In the earliest stage, the tendon is inflamed but the arch still looks normal on an X-ray. You can still rise onto your toes on one foot, though it may hurt. Pain and mild swelling along the inner ankle are the main clues.
In stage two, the arch visibly collapses. You can no longer do a single-leg heel raise without difficulty or pain. The foot begins to splay outward, producing what’s called the “too many toes” sign: if someone stands behind you, they can see more of your toes peeking out on the affected side than on the other. At this point the foot is still flexible, meaning the deformity can be manually corrected.
By stage three, the joints in the back of the foot develop arthritis. The flatfoot position becomes rigid, meaning it can no longer be pushed back into a normal shape. In stage four, the damage extends to the ankle joint itself. The ankle tilts inward because the ligaments on the inner side have given way, and arthritis spreads further.
Where You’ll Feel It
The earliest symptom is usually pain along the inner side of the ankle or in the arch itself. It tends to get worse with activity, especially walking or standing for long periods, and improves with rest. Swelling often develops along the inside of the ankle, right behind the ankle bone where the damaged tendon runs.
As the arch drops further, the outer ankle can start to hurt too. The heel bone shifts outward, which can pinch the tendons and nerves on the outside of the ankle against the bone below it. Some people also develop pain on the top of the foot as the midfoot bones shift position and compress against each other. Heel pain resembling plantar fasciitis is common because the tissue along the sole of the foot gets overstretched.
How Fallen Arches Affect Your Knees and Back
Your foot is the foundation of a chain of joints that extends up through the ankle, knee, hip, and spine. When the arch collapses, the shin bone rotates inward more than it should during walking. This inward twist changes how forces travel through the knee. Research has linked flat feet in older adults to knee pain and cartilage damage, particularly in the inner compartment of the knee where the rotational stress is greatest.
That same inward rotation of the shin bone can also push the kneecap against the outer wall of its groove, contributing to pain at the front of the knee. Further up the chain, the thigh bone may rotate inward as well, altering hip mechanics and tilting the pelvis. When the pelvis tilts, the lower back compensates. This is why some people with fallen arches develop chronic lower back pain that doesn’t respond to back-focused treatment: the root cause is two feet below.
Long-Term Complications if Left Untreated
Without intervention, the progressive misalignment of the foot creates conditions for secondary problems. Arthritis in the midfoot and rearfoot joints is the most significant. Once the bones sit in abnormal positions for months or years, the cartilage wears unevenly, and the joint damage becomes permanent.
Toe deformities also become more likely. As the arch flattens, the mechanics of push-off during walking change, placing abnormal stress on the smaller toes. This can lead to hammertoes, where the middle joint of a toe bends upward and becomes fixed in that position, or claw toes, where all three joints of a toe curl. Bunions can worsen for similar reasons: the altered foot mechanics push the big toe progressively outward.
A Simple Self-Test
The single-leg heel raise is the quickest way to check your arch-supporting tendon at home. Stand on one foot and try to rise onto your toes, lifting your heel about two to three centimeters off the ground. A healthy tendon allows you to do this repeatedly, at least eight to ten times, with your heel turning slightly inward as you rise. If you can’t rise onto your toes at all, or if your heel stays tilted outward when you try, the tendon is likely compromised. Pain or wobbling during the attempt is also a meaningful signal, even if you can technically complete the motion.
Exercises That Help Rebuild Arch Support
The small muscles inside the foot can be strengthened to partially compensate for a weakened tendon, especially in the earlier stages. The most well-studied exercise is the arch lift, sometimes called foot doming. With your foot flat on the floor, you raise the arch as high as you can by pulling the ball of your foot toward your heel, rolling your weight to the outer edge of the foot while keeping both your heel and toes in contact with the ground. You can do this sitting or standing. It targets the intrinsic muscles of the foot and has also been shown to help with plantar fasciitis.
Calf stretching matters too, because a tight calf muscle increases the load on the arch-supporting tendon. If the calf can’t flex enough during walking, the foot compensates by collapsing inward. Towel curls (gripping a towel with your toes), heel raises on both feet, and resistance-band exercises that strengthen the muscles responsible for turning the foot inward all support the arch from different angles. Consistency over weeks and months matters more than intensity on any single day.
Footwear and Orthotics
Shoes play a bigger role than most people expect. Two features matter most: a firm midsole that resists twisting when you wring the shoe like a dishrag, and a solid heel counter (the rigid cup at the back of the shoe that wraps around your heel). Together, these limit the inward rolling motion that worsens arch collapse. Flexible, unsupportive shoes like ballet flats, worn-out sneakers, or most sandals allow the foot to pronate freely and accelerate the problem.
Over-the-counter arch supports can provide meaningful relief for mild to moderate cases. Custom orthotics, molded to the specific shape of your foot, are typically recommended when off-the-shelf inserts aren’t enough. They work by redistributing pressure across the sole and holding the heel in a more neutral position. Orthotics don’t reverse structural damage, but they can slow progression and significantly reduce pain.
When Surgery Becomes Necessary
Most people with fallen arches never need surgery. Orthotics, physical therapy, and footwear changes manage the majority of cases, particularly those caught in the first two stages. However, obesity has been linked to higher rates of failing non-surgical treatment.
When conservative approaches don’t control the pain, or when the deformity becomes rigid, surgical options range from tendon repair and bone realignment to joint fusion, depending on the stage. Recovery is lengthy. A typical timeline involves about two weeks in a cast, then four more weeks in a walking boot, with full weight-bearing walking (without a boot or crutches) starting around six weeks after surgery. Pivoting and athletic activities are generally off-limits for at least six months. Strength training and balance work continue for up to a year, and full functional recovery in one case study took 19 months.
The single most important factor in avoiding surgery is catching the problem early, while the foot is still flexible and the joints are free of arthritis. Once the deformity becomes rigid and arthritic, the surgical options become more invasive and the recovery longer.