Crooked toes are overwhelmingly the result of muscle imbalance, where the small muscles inside your foot weaken or lose their ability to counterbalance the stronger tendons running down from your leg. That imbalance pulls joints into flexed or extended positions they were never meant to hold permanently. But the story is rarely that simple: genetics account for a surprisingly large share of who develops toe deformities, footwear plays a role that compounds over decades, and conditions like rheumatoid arthritis or inherited nerve disorders can accelerate the process dramatically.
How Toe Deformities Actually Develop
Your toes stay straight thanks to a tug-of-war between two sets of muscles. The intrinsic muscles, small ones that live entirely within the foot, work to flex the toe joints closest to the ball of your foot while keeping the smaller joints farther out relatively straight. The extrinsic muscles, which originate in your lower leg and send long tendons into your toes, do the opposite: they pull the base joint upward and curl the outer joints down. When the intrinsic muscles weaken or stop doing their job, the extrinsic tendons win the tug-of-war unopposed, and your toes start bending into abnormal positions.
Research has quantified this imbalance clearly. In people with hammer toes, the ratio of extensor-to-flexor muscle strength in the lesser toes was roughly two to three times higher than in people with straight toes, and that ratio alone accounted for about half to two-thirds of the abnormal joint angle.
1PubMed Central. Muscle imbalance and reduced ankle joint motion in people with hammer toe deformityThe deformity tends to progress through stages. Early on, the bent joint is still flexible; you can straighten the toe with your hand, and the muscles and tendons have not yet permanently shortened. Over time, however, the soft tissues adapt to the new position. Tendons contract, the joint capsule tightens, and eventually the deformity becomes rigid. That flexible-to-rigid progression is the single most important factor in determining how easy the problem is to treat.
Hammer Toe, Claw Toe, and Mallet Toe
People use “crooked toes” as a catch-all, but clinicians distinguish between several patterns based on which joints are bent and in which direction. The differences matter because they point to different underlying causes and respond to different treatments.
- Hammer toe: The middle joint of the toe (the proximal interphalangeal joint) bends downward into a flexed position while the base joint and tip joint may stay relatively neutral. This is the most common lesser toe deformity and typically affects the second toe.
- Claw toe: The base joint hyperextends upward while the middle and tip joints both curl downward. The distinguishing feature is that upward extension at the base, which creates a claw-like appearance. 2PubMed. Definitions of hammer toe and claw toe: an evaluation of the literature
- Mallet toe: Only the tip joint (distal interphalangeal joint) flexes downward, leaving the other joints relatively straight. This tends to cause problems at the very end of the toe, where it presses into the ground or the shoe.
In practice, these deformities often overlap or coexist on different toes of the same foot. A person might have a hammer toe on their second toe and a claw toe on the third and fourth. The underlying mechanism, intrinsic muscle weakness letting extrinsic tendons dominate, drives all three patterns, but the specific anatomy of each toe’s tendon attachments determines which pattern emerges.
Why Bunions Make Everything Worse
If you have a bunion (hallux valgus), there is a good chance your second and third toes are crooked too, and that is not a coincidence. When the big toe drifts outward toward the smaller toes, it physically crowds them and disrupts the mechanical balance of the entire forefoot. The chronic lateral deviation of the big toe leads to flexion contracture at the second toe’s middle joint, subluxation at its base joint, and can ultimately produce a crossover deformity where the second toe rides over or under the big toe.3Foot & Ankle Orthopaedics. The Influence of Concomitant Hammertoe Correction on Postoperative Outcomes in Patients Undergoing Hallux Valgus Correction
The relationship is dose-dependent. A larger bunion angle correlates with a higher likelihood of second-toe hammer toe, and each additional degree of hallux valgus angle was associated with roughly a five percent greater chance of having a hammer toe alongside the bunion.4Foot & Ankle Orthopaedics. Do Radiographic and Clinical Parameters in the Setting of a Bunion Predict Second Ray Pathology? Increased age, which essentially serves as a proxy for how long the bunion has been present, further raises the risk. This is one reason foot specialists often recommend addressing bunions before the secondary deformities become fixed.
The plantar plate, a thick ligament on the underside of each toe joint, also plays a central role. When the bunion shifts mechanical loads onto the second metatarsal head, the plantar plate of the second toe gradually stretches and weakens. Once that ligament becomes insufficient, the base joint loses its stability, and the toe drifts upward and curls.5PubMed Central. Claw Toe With Dislocated Second Metatarsophalangeal Joint: Treated by Plantar Plate Tenodesis and Release of Collateral Ligaments Plantar plate tears are common enough that they have become a recognized diagnosis in their own right, separate from generic “hammer toe.”
The Footwear Factor
Shoes with a narrow toe box, elevated heels, or both compress the toes into positions that reinforce the same muscle imbalances described above. High heels shift your body weight forward onto the ball of the foot and the toes, overloading the metatarsal heads and encouraging the base joints to hyperextend. A tight toe box holds the toes in a bunched position for hours, preventing the intrinsic muscles from working through their full range. Over years, this chronic compression accelerates the progression from flexible to rigid deformity.
That said, footwear is rarely the sole cause. Plenty of people who wear narrow shoes their entire lives never develop significant toe deformities, while others who wear roomy footwear still end up with crooked toes. The difference usually comes down to the genetic and structural factors working underneath the shoe.
Genetics Play a Bigger Role Than Most People Expect
If your parents or grandparents had crooked toes, your odds of developing them are substantially higher, and the research backing this up is striking. A study of adult twins found that the heritability of lesser toe deformities ranged from about 0.49 to 0.90, depending on age and sex. For men and women over 70, the heritability was around 0.65. Hallux valgus showed a similarly wide range, from 0.29 to 0.89.6PubMed Central. High heritability of hallux valgus and lesser toe deformities in adult men and women
Heritability numbers like these mean that genetics explain roughly half to the vast majority of the variation in who gets these deformities, leaving a comparatively modest role for environmental factors like footwear and occupation. What is being inherited is not a “crooked toe gene” per se, but rather foot shape, arch height, metatarsal length ratios, ligament laxity, and intrinsic muscle architecture, all of which set the stage for deformities to develop or not develop over a lifetime. This is why some families see bunions and hammer toes appearing across multiple generations even when their shoe habits differ considerably.
When Systemic Disease Is the Cause
Not all crooked toes are a gradual consequence of mechanics and genetics. In some cases, the deformity points to an underlying medical condition that needs its own treatment.
Rheumatoid Arthritis
Rheumatoid arthritis frequently targets the forefoot. The chronic inflammation erodes joint cartilage, weakens the supporting ligaments, and causes the base joints of the lesser toes to sublux or fully dislocate dorsally. This produces claw toes alongside hallux valgus, often in a recognizable pattern where the toes drift laterally and the metatarsal heads become prominent and painful on the sole of the foot.7PubMed Central. Rheumatoid forefoot deformity: pathophysiology, evaluation and operative treatment options Despite advances in medication, forefoot deformity remains common enough in rheumatoid patients that surgical correction is frequently needed.
The damage tends to be worse in the outer toes. When the lesser toe joints fully dislocate, the cartilage destruction is most severe in the fourth and fifth toes compared to the second and third.8PubMed. Higher association of articular surface destruction with rheumatoid forefoot deformity arising from dislocation of the metatarsophalangeal joints in the lateral column That lateral-column severity matters because it means rheumatoid forefoot correction sometimes requires addressing all the lesser toes, not just the obviously deformed second toe.
Charcot-Marie-Tooth Disease and Other Nerve Conditions
Charcot-Marie-Tooth disease, an inherited condition that damages peripheral nerves, is one of the classic neuromuscular causes of claw toes. As the intrinsic foot muscles lose their nerve supply, the extrinsic muscles go unopposed. The base joints hyperextend and the interphalangeal joints flex, producing the claw-foot deformity that is almost a hallmark of the disease.9International Journal of Foot and Ankle. Charcot-Marie-Tooth Disease: Updates in Diagnosis and Treatment Guidelines Pertaining to the Lower Extremity and Case Study Other conditions that damage the nerves supplying the foot, including diabetes and spinal cord injuries, can produce similar patterns.
The distinguishing clue with neurological causes is that the deformity often affects all the lesser toes relatively symmetrically and is accompanied by other signs: a high arch (cavus foot), muscle wasting in the lower leg, difficulty with balance, or numbness. If your toes started curling in your teens or twenties, or if both feet are affected in a strikingly similar pattern, it is worth asking a doctor whether an underlying nerve condition could be responsible.
Curly Toes in Children
Congenital curly toes are a separate phenomenon from the adult deformities discussed above. Babies and toddlers can be born with toes, usually the third, fourth, or fifth, that curl under and rotate inward. The condition is common enough to appear in roughly three percent of newborns, and the good news is that a quarter to half of cases resolve on their own without any intervention.10PubMed Central. Congenital Curly Toes in the Pediatric Population: A Management Algorithm and Systematic Review
For those that persist, taping in the newborn period appears to be remarkably effective. A prospective study of 84 affected toes found that starting a simple taping technique in the newborn period produced improvement or cure in 94 percent of toes, with no complications from the tape itself.11PubMed Central. Prospective study of a noninvasive treatment for two common congenital toe abnormalities (curly/varus/underlapping toes and overlapping toes) That is far better than the historical expectation of 25 percent spontaneous improvement quoted in standard textbooks. The catch is that taping works best when started early; once the child is older and the soft tissues have adapted, conservative measures become less reliable, and surgery may eventually be needed for toes that cause pain or shoe-fitting problems.
Conservative Treatments for Adults
When toe deformities are still in the flexible stage, non-surgical approaches can reduce pain, slow progression, and sometimes improve alignment. The goal is usually to restore some balance between the intrinsic and extrinsic muscles, protect the skin from pressure, and accommodate the deformity in footwear.
- Wider shoes: Switching to shoes with a spacious toe box and a low heel removes the external force that worsens the deformity. This alone can resolve symptoms in mild cases, even if it does not fully straighten the toe.
- Silicone toe props and orthoses: Custom-molded silicone devices placed around or between the toes can significantly reduce peak plantar pressure. In people with rigid toe deformities, these props lowered pressures both at the toe tip and at the base joint.12PubMed. Conservative Approach in the Management of Lesser Toe Deformities in Older Adults For people with diabetes, where pressure under the toes raises the risk of skin breakdown, combining debridement of calluses with a silicone orthosis reduced digital plantar pressure more effectively than either treatment alone.13PubMed. Reduction of digital plantar pressure by debridement and silicone orthosis
- Toe exercises and intrinsic muscle training: Strengthening the intrinsic foot muscles through targeted exercises (sometimes called “foot core” training) can help restore the muscular balance that keeps toes aligned. Clinicians increasingly recognize that intrinsic muscle dysfunction contributes to a variety of foot problems, and rehabilitation focused on these muscles is a growing area of treatment.
- Taping and splinting: Especially useful for flexible deformities, tape or small splints can hold a toe straighter during the day and may slow progression, though the evidence for long-term correction in adults is less impressive than in newborns.
The key limitation of all conservative measures is that they cannot reverse a rigid deformity. Once the joint is fixed in a bent position and the tendons have permanently shortened, no amount of padding, taping, or exercise will straighten it. Conservative treatment at that stage is about managing symptoms: preventing calluses, reducing pain, and protecting the skin.
When Surgery Becomes the Right Choice
Surgery is generally considered when the deformity is rigid, painful, or causing secondary problems like skin ulceration that cannot be managed conservatively. The specific procedure depends on which joints are involved, how severe the deformity is, and whether the toe is still partially flexible.
For flexible deformities, tendon transfer procedures can rebalance the forces acting on the toe. One approach takes the long flexor tendon, the one curling the toe downward, and redirects it to the top of the toe so it becomes a corrective force instead of a deforming one. A newer variation uses a specific implant to attach both the long and short flexor tendons to the underside of the first bone in the toe, allowing dynamic correction at both the base and interphalangeal joints without the stiffness that sometimes follows older techniques.14PubMed Central. Flexor tenodesis procedure in the treatment of lesser toe deformities
For rigid deformities, the standard approach is fusion (arthrodesis) of the bent joint, usually the proximal interphalangeal joint. The surgeon removes the damaged cartilage surfaces and pins or screws the joint in a straight position, allowing the bone ends to grow together. A study of patients undergoing this procedure found that it had lower rates of residual pain, infection, mallet toe deformity, and reoperation compared to some alternative techniques, with an overall revision rate of just under seven percent.15PubMed Central. Patient-Reported Outcome Measurement Information System Measures for Proximal Interphalangeal Joint Arthrodesis in Lesser Toe Deformities
Minimally invasive percutaneous techniques are an expanding option. These procedures use small incisions and specialized instruments to cut bone or release soft tissues through the skin rather than opening the toe fully. For hallux valgus correction, the evidence base for minimally invasive surgery is substantial, with systematic reviews showing comparable functional and radiographic outcomes to open surgery, along with potential advantages in wound healing and early postoperative pain.16PubMed. Minimally invasive percutaneous surgery techniques for common foot & ankle pathologies: Current concepts and clinical outcomes For lesser toe corrections, the evidence is growing but not yet as robust.
When a bunion is driving the lesser toe deformity, addressing the bunion alone sometimes allows the second or third toe to realign on its own. In other cases, the lesser toe deformity has become independent of the bunion and requires its own correction at the same time.17PubMed. Influence of the presence or absence of the second hammertoe on clinical effect of hallux valgus
How Doctors Evaluate Crooked Toes
A physical exam remains the primary tool. The clinician will check whether the deformity is flexible or rigid by attempting to manually straighten the toe, assess the stability of the base joint by testing for plantar plate integrity, and look for calluses or skin breakdown that signal pressure problems. They will also evaluate your gait, arch height, and the position of your big toe, since all of these affect the lesser toes.
Standard X-rays under weight-bearing conditions show the bone alignment and joint spacing. In more complex cases, particularly when surgery is being planned for multiple deformities or when flatfoot or ankle instability complicates the picture, weight-bearing CT scans provide a three-dimensional view of the bones under actual loading conditions. These scans have changed how surgeons understand alignment in conditions like hallux valgus and adult flatfoot, revealing subtleties that conventional X-rays miss.18PubMed Central. Weight-bearing CT Scans in Foot and Ankle Surgery
Dorsal Dislocation and the Diabetes Connection
One complication of severe lesser toe deformity that deserves special attention is dorsal dislocation of the base joints. When the toe rides up and the metatarsal head pushes down against the sole, it creates a bony prominence under the ball of the foot. In most people, this causes painful calluses. In people with diabetes, who often have reduced sensation and impaired circulation, the same prominence can generate ulcers that are slow to heal and prone to infection.19PubMed Central. A Novel Radiographic Measurement Method for the Evaluation of Metatarsophalangeal Joint Dislocation of the Lesser Toe in Patients with Rheumatoid Arthritis
This is why podiatrists and diabetic foot specialists take toe deformities seriously even when the patient is not in pain. In a foot with diminished nerve function, pain is not a reliable alarm. Pressure offloading through orthoses, callus management, and proactive surgical correction of severe deformities all serve to prevent wounds that can, in the worst case, lead to amputation. If you have diabetes and notice your toes curling or shifting, that is worth bringing up at your next appointment rather than waiting for symptoms to develop.