A toe that curls up almost always traces back to a muscle imbalance in or around the foot, where the tendons that pull the toe upward or downward are no longer working in proper proportion. The exact cause ranges from shoes that crowd your toes to nerve damage, neurological conditions, or something you were born with. What makes the topic more interesting than a simple anatomy lesson is that the same visible symptom, a toe bending where it shouldn’t, can stem from completely different mechanisms depending on who you are, how old you are, and what else is going on in your body.
The Muscle Imbalance That Drives Most Curled Toes
Your lesser toes (the four smaller ones) each have extensor tendons on top that pull the toe up and flexor tendons underneath that curl it down. In a healthy foot, these forces stay roughly balanced, keeping the toe flat during walking and push-off. When the balance tips, the toe buckles. Research comparing people with hammer toes to those without found that the ratio of extensor-to-flexor muscle strength was two to three times higher in the hammer toe group, and that this strength ratio alone accounted for roughly half to two-thirds of the abnormal upward angle at the base of the toe.1PubMed Central. Muscle imbalance and reduced ankle joint motion in people with hammer toe deformity In plain terms, the muscles pulling the toe up had become disproportionately strong relative to the muscles holding it down, and the toe responded by rising at the base joint and curling at the middle.
That same study also found significantly reduced ankle range of motion in people with hammer toes. A tight calf or Achilles tendon shifts more pressure to the front of the foot during walking, which over time forces the small muscles inside the foot to compensate in ways they aren’t designed for. This is one reason hammer toes are so common in people who spend decades in heeled shoes or stiff-soled footwear: the calf shortens, the forefoot takes more load, and the intrinsic muscles gradually lose the tug-of-war.
Hammer Toes, Claw Toes, and Mallet Toes Are Not the Same Thing
People use “curled toe” as a catch-all, but clinicians distinguish between three patterns based on which joints are bent. Each one involves different tendons and carries slightly different implications for treatment.
- Hammer toe: The middle joint of the toe bends downward while the tip stays relatively flat. This is the most common deformity in the second toe and is strongly linked to shoes that are too short or too narrow.
- Claw toe: Both the middle and end joints curl downward while the base joint hyperextends upward, giving the toe a claw-like appearance. Claw toes more often affect all four lesser toes at once and are frequently tied to nerve damage or systemic conditions.
- Mallet toe: Only the joint nearest the tip bends downward. It is the least common of the three and tends to cause problems mainly with shoe fit and pressure on the tip of the toe.
The distinction matters because a hammer toe caught early is often still flexible, meaning you can manually straighten it. A claw toe, especially one driven by neuropathy, may already be rigid by the time you notice it. The treatment window for conservative measures is much wider for a flexible deformity than for a stiff one.
Diabetic Neuropathy and Claw Toes
If you have diabetes and notice your toes curling, nerve damage is the most likely culprit. Diabetic peripheral neuropathy gradually destroys the small nerves that control the intrinsic muscles of the foot. As those muscles waste away, the longer extrinsic muscles running down from the leg take over, and because they pull across multiple joints, the toes claw. Imaging research has confirmed this connection directly: people who had both neuropathy and claw toes showed significantly smaller intrinsic foot muscle volume compared to every other group, whether those others had neuropathy alone, claw toes alone, or neither.2PubMed Central. Neuropathy, claw toes, intrinsic muscle volume, and plantar aponeurosis thickness in diabetic feet The combination of nerve damage and muscle wasting seemed to work together in a way that neither factor did on its own.
This matters beyond cosmetics. Clawed toes in a diabetic foot change where pressure lands during walking, concentrating force under the metatarsal heads and on the tops of the bent joints. That creates exactly the kind of focal pressure that leads to ulcers and infections in someone whose sensation is already diminished. If you have diabetes and notice any toe deformity, it deserves attention even if it doesn’t hurt, precisely because reduced sensation may mean you can’t feel the damage it’s causing.
Nerve Entrapment in the Ankle
Tarsal tunnel syndrome is sometimes called the foot’s version of carpal tunnel syndrome. The tibial nerve passes through a narrow channel behind the inner ankle bone, and when that tunnel gets crowded, whether from swelling, a cyst, or even an extra muscle, the nerve gets compressed. The result can include pain, tingling, and involuntary toe curling or flexion spasms.
Case reports illustrate how varied this can look. In one patient, an unusually large accessory soleus muscle was found to be compressing structures inside the tarsal tunnel, producing painful involuntary toe movements. Blocking the plantar nerves downstream temporarily stopped the movements, confirming that the problem originated at the compression site.3PubMed. Painful legs and moving toes associates with tarsal tunnel syndrome and accessory soleus muscle In another case, a 29-year-old woman with bilateral tarsal tunnel syndrome caused by an accessory muscle in both feet experienced immediate relief after surgical decompression.4PubMed. Bilateral Flexor Digitorum Accessorius Longus Precipitating Bilateral Tarsal Tunnel Syndrome: A Case Report Even in paraplegic patients, compression within the tarsal tunnel has been shown to provoke flexor spasms in the toes, and surgical release significantly reduced those spasms.5PubMed. Latent tarsal tunnel syndrome with the provocation of flexor spasms in a paraplegic person. Case report
The takeaway is that if your toe curling comes with burning, tingling, or electric sensations in the sole of your foot, the nerve running through your ankle deserves investigation. This is an underdiagnosed condition, partly because the symptoms overlap with plantar fasciitis and other common foot complaints.
Parkinson’s Disease and the “Striatal Toe”
A striatal toe is an involuntary upward extension of the big toe that occurs in Parkinson’s disease and related movement disorders. It looks superficially like a neurological reflex sign but differs in that the other toes don’t fan outward the way they would in a true corticospinal tract problem.6PubMed. The frequency and significance of ‘striatal toe’ in parkinsonism In a prospective study of 62 patients with parkinsonism, about one in five showed an upgoing toe, and most of those were classified as striatal toes rather than the classic Babinski response. The striatal toe appeared in both Parkinson’s disease and other akinetic-rigid syndromes, sometimes on just one side.
Beyond the big toe, Parkinson’s patients often experience “wearing-off” foot dystonia, where the foot and toes cramp and curl involuntarily as medication levels drop between doses. A 54-year-old woman initially attributed her progressive toe cramping and curling to a bunion, but her symptoms turned out to be a rare case of primary adult-onset focal foot dystonia.7PubMed Central. Adult onset primary focal dystonia of the foot: an orthopaedic intervention The point of the case was that dystonic toe curling can be mistaken for a mechanical foot problem, delaying neurological evaluation. If your toes curl involuntarily and the curling worsens during movement or at specific times of day, dystonia is worth discussing with a neurologist.
Research on treatment is still relatively thin, but one review noted that few data exist on the prevalence, origin, and best therapy for the striatal toe, despite it being a recognized feature of the disease.8PubMed Central. Striatal Toe: Too Harmless to Treat?
Congenital Curly Toes in Children
If your child’s toes curl under and seem to rotate inward, this is likely congenital curly toe, the most common congenital toe abnormality, affecting an estimated two to three percent of the population. It usually involves the third, fourth, or fifth toes and runs in families.9PubMed Central. Congenital Curly Toes in the Pediatric Population: A Management Algorithm and Systematic Review The encouraging news is that somewhere between a quarter and half of cases resolve on their own as the child grows. For the ones that persist and cause pain or shoe-fitting problems, taping and strapping are often tried first, with surgery reserved for cases that remain symptomatic.
Parents sometimes worry that curly toes signal a larger skeletal problem, but isolated congenital curly toes are a local soft-tissue issue, not an indicator of systemic disease. The tendons on the underside of the affected toe are simply too tight relative to those on top, and in many toddlers, the growing foot naturally resolves this tension.
Trauma and Compartment Syndrome
A less common but serious cause of toe clawing is ischemic contracture following compartment syndrome in the lower leg. Compartment syndrome happens when pressure builds up inside a muscle compartment, usually after a fracture, cutting off blood flow. If not relieved quickly, the muscles in that compartment die and are replaced by stiff scar tissue, which permanently shortens the tendons running to the toes. Clawing of the toes is a well-documented consequence of this process.10The Journal of Foot and Ankle Surgery. A Practical Correction of Great Toe Claw Deformity
In one reported case, a patient developed obvious toe clawing six weeks after an ankle fracture. The deep posterior compartment had been damaged, causing ischemic contracture of the long toe flexor muscles. The clawing was ultimately corrected by surgically lengthening the flexor hallucis longus and flexor digitorum longus tendons, producing full correction of all toes.11PubMed. Ischemic contracture of deep posterior compartment of the leg following isolated ankle fracture The key message is that severe, persistent pain after a leg or ankle injury should be treated as a potential emergency. Compartment syndrome needs surgical release within hours, not days, to prevent this kind of permanent damage.
What You Can Do Without Surgery
For flexible deformities, meaning toes you can still manually straighten, conservative measures are the first line of defense. The goal is to rebalance pressures and maintain or restore mobility before the joint stiffens permanently.
- Roomier shoes: Switching to a shoe with a wide, deep toe box removes the external force that is pushing the toe into a bent position. This alone can halt progression in mild cases.
- Toe props and silicone orthoses: A custom silicone device fitted at the base joint of a hammer or claw toe can reduce peak plantar pressure, particularly in toes that have already stiffened.12PubMed. The effectiveness of shoe modifications and foot orthoses in conservative treatment of lesser toe deformities: a review of literature Interestingly, one review found that these devices helped more in the rigid stage of deformity than the flexible one, which is the opposite of what you might expect. Separately, toe props placed under curled toes significantly reduced pressure under the affected toes and the metatarsal heads in the majority of feet tested.13PubMed. Effect of orthotic therapy on claw toe loading: results of significance testing at pressure sensor units
- Toe stretches and manual exercises: Regularly stretching the toe joints through their full range of motion can preserve flexibility. Picking up small objects with your toes, spreading your toes apart, and towel scrunches all target the intrinsic foot muscles that tend to weaken in curled-toe conditions.
- Calf stretching: Since tight calves contribute to forefoot overload, maintaining ankle flexibility is part of the bigger picture.
An intriguing line of research suggests that simply spending more time in minimal footwear, shoes with thin, flexible soles and no arch support, can meaningfully strengthen the intrinsic foot muscles. One study found that people who switched to minimal shoes for daily activity saw their toe flexion strength increase by an average of about 57% over the study period, a large effect that was absent in the control group.14PubMed Central. Daily activity in minimal footwear increases foot strength Stronger intrinsic muscles could, in theory, help resist the muscle imbalance that leads to toe deformity, though no trial has yet directly tested whether minimal footwear prevents hammer toes or claw toes from forming.
Botulinum Toxin for Neurological Toe Curling
When toe curling is driven by dystonia rather than structural deformity, botulinum toxin injections into the overactive muscles can provide significant relief. The toxin temporarily weakens the muscle it’s injected into, breaking the involuntary contraction cycle. For Parkinson’s patients experiencing foot dystonia, multiple clinical reports describe this approach as effective in most cases.15PubMed Central. Use of botulinum toxin in the management of dystonia in Parkinson’s disease
In a pilot study of Parkinson’s patients with foot dystonia who were also receiving deep brain stimulation, botulinum toxin injections led to significant improvements in dystonia severity, pain, walking distance, gait speed, and cadence within three weeks.16PubMed. Botulinum toxin for foot dystonia in patients with Parkinson’s disease having deep brain stimulation: A case series and a pilot study A separate study focused on “hitchhiker’s toe,” where the big toe involuntarily extends, found that botulinum toxin was effective in 83% of treated patients.17PubMed. Botulinum Toxin in the management of hitchhiker’s toe The effects typically last a few months before repeat injection is needed, so this is a management tool rather than a cure, but for people whose daily walking is disrupted by involuntary toe postures, the improvement in function can be substantial.
When Surgery Makes Sense
Surgery enters the picture when the deformity is rigid, when conservative methods have failed, or when the curled toe is causing skin breakdown or unacceptable pain. The two broad surgical approaches for hammer and claw toes involve different trade-offs.
Joint fusion, where the bent joint is straightened and permanently fixed, is the most reliable way to correct the visible deformity. Finite-element modeling has shown it produces the greatest reduction in upward displacement of the proximal phalanx. However, the same analysis found that it actually increases stress on the bone compared to the pre-surgery state, which may contribute to post-operative pain in some patients.18PubMed. Advantages and drawbacks of proximal interphalangeal joint fusion versus flexor tendon transfer in the correction of hammer and claw toe deformity. A finite-element study Tendon transfer, where the flexor tendon is rerouted to act as a stabilizer, reduces bone stress by roughly 35 to 40 percent compared to the deformed state but does not correct the dorsal displacement as completely as fusion does.
Overall, pain relief with successful hammer toe correction approaches 90%, and patient satisfaction rates sit around 84%.19PubMed. Treatment of Rigid Hammer-Toe Deformity: Permanent Versus Removable Implant Selection Those are good numbers, but they also imply that roughly one in six patients is dissatisfied, often because of residual stiffness, swelling, or a toe that looks straighter but doesn’t bend the way it used to.
A newer frontier is minimally invasive surgery (MIS), performed through small incisions with specialized burrs rather than the traditional open approach. A prospective randomized study comparing the two techniques found that clinical and radiological correction were comparable, but the open surgery group had significantly more wound complications, including infections, and significantly more non-unions. At 18 months, the minimally invasive group had 100% bone healing, while the open group achieved complete bony healing in only about 88% of toes.20PubMed Central. Correction of lesser toe deformities: minimally invasive versus open surgery—a prospective randomised study Both groups did experience wire-related complications, though the types differed: wire migrations in the MIS group versus wire deformations in the open group. The evidence is still early, but for patients worried about healing and infection risk, minimally invasive techniques look promising.
How to Tell Which Cause Applies to You
The pattern and timing of your toe curling gives strong clues about what’s behind it. A single toe that gradually curled over years, especially the second toe next to a bunion, is almost certainly a mechanical problem driven by footwear and biomechanics. Multiple toes clawing on both feet, particularly with numbness or tingling in the soles, points toward neuropathy, and diabetes should be tested for if it hasn’t been already. A toe that involuntarily extends or curls during movement and relaxes at rest suggests dystonia or another neurological cause. Sudden onset after an injury, especially with severe pain, demands urgent evaluation for compartment syndrome.
The flexibility test is the simplest thing you can do at home: try to manually straighten the affected toe. If it moves easily into a flat position, the deformity is flexible and you likely have time to address it conservatively. If the toe resists and stays bent, the joint has already stiffened, and you’ll benefit from a clinical evaluation sooner rather than later. A podiatrist or orthopedic foot specialist can distinguish between the various deformity types, check for underlying nerve issues, and help you decide whether conservative measures or more active intervention is the right next step.