Toes do far more than fill out the front of your shoes. They generate the push-off force that propels you forward with every step, help stabilize the arch of your foot under load, and provide the sensory feedback your brain needs to keep you upright on uneven ground. Lose even one toe and the biomechanics of your entire gait shift in measurable ways. The story of why we need toes touches on walking mechanics, balance control, evolutionary history, and even the design of modern robotic limbs.
The Big Toe and the Push-Off Phase
Walking looks simple, but the final instant before your foot leaves the ground is a surprisingly demanding event. During this push-off phase, the first and second metatarsal heads (the ball of the foot behind those two toes) and the big toe together bear roughly 64% of the total forefoot load.1The Foot. Pressure and force distribution characteristics under the normal foot during the push-off phase in gait The big toe is the last structure to press against the ground before your foot lifts, and the force it exerts increases significantly as walking speed goes up.2Journal of Biomechanics. EMG and force production of the flexor hallucis longus muscle in isometric plantarflexion and the push-off phase of walking That speed-dependent force increase is greater under the big toe than under any other part of the foot, which is why losing or injuring this single digit has an outsized effect on how well a person walks.
The lesser toes contribute too, though their individual shares are smaller. They fan out to widen the base of support during push-off, and their flexor muscles fire collectively to stabilize the forefoot against the ground. But the big toe is the star. Its long flexor tendon, the flexor hallucis longus, acts almost like a lever arm that converts downward force into forward momentum. Think of it as the last point of contact in a chain reaction: your heel strikes, your weight rolls forward over the midfoot, and the big toe finishes the job by pushing you into the next stride.
How Toe Extension Supports the Arch
Your foot has a built-in mechanism for stiffening itself at exactly the right moment, and your toes are central to it. When your toes bend upward (dorsiflex) during push-off, the thick band of tissue running along the sole, the plantar fascia, tightens and pulls the heel closer to the ball of the foot. This raises and stiffens the longitudinal arch, turning the foot into a rigid lever rather than a floppy platform. Researchers call this the windlass mechanism, named after the crank on a ship’s anchor chain.
During walking, the arch rises substantially more than it does when you simply sit or stand and curl your toes back. One study measured a rise of about 11 mm in the arch during walking push-off, compared to roughly 6–7 mm while sitting and about 5–6 mm while standing.3PLOS ONE. The rise of the longitudinal arch when sitting, standing, and walking: Contributions of the windlass mechanism The difference comes from the dynamic loading of walking: your body weight is rolling forward over the toes, which bends them back further and faster than in a static posture. Interestingly, the arch does not start rising immediately when the toes begin to extend during a walking stride. There is a brief delay, on the order of about 8–9 degrees of toe extension, before the arch begins to climb. Before that threshold, the arch actually drops slightly as the foot absorbs force.
Under full body weight, the muscle that matters most to this mechanism appears to be the flexor digitorum brevis, a short muscle running along the sole. When you’re sitting with minimal load on the foot, both the plantar fascia and this muscle share the windlass duty. But when you stand on one leg or walk, the flexor digitorum brevis becomes the main driver.4Scientific Reports. Reconsideration of the load-bearing functions of the plantar fascia and intrinsic foot muscles in the windlass mechanism This is why people with weak intrinsic foot muscles sometimes develop flat feet or foot pain during walking: their windlass mechanism is not stiffening the arch efficiently.
Toes and Standing Balance
Standing upright is an act of constant, tiny corrections. Your body sways forward and backward, and your feet are the platform that detects and counters those sways. The toes play a specific role here: when you start to tip forward, the toe flexor muscles grip the ground and pull you back. The faster those muscles can generate force, the smaller the corrections you need.
Research in young adults found that men who could develop toe-grip force more quickly showed less postural sway, measured as the area their center of pressure traced on a force plate.5PubMed Central. Relationship between balance ability and rate of force development of toe grip strength in young adults The relationship was less clear in young women in that particular study, possibly reflecting differences in balance strategies or body proportions. But the broader point holds: the ability to grip quickly with your toes is part of how your body keeps you from toppling.
The toes are also sensory organs. The skin under the big toe is rich in mechanoreceptors that detect pressure and texture. When researchers applied mild sensory stimulation under the big toe of patients with fibromyalgia (who tend to have poor balance), the patients’ postural sway improved. Their center of pressure shifted forward and became more stable, suggesting the brain was making better balance corrections simply because it was getting clearer signals from the toe.6PubMed. Effect of sensory stimulation applied under the great toe on postural ability in patients with fibromyalgia That finding lines up with a broader principle: balance is not just about muscle strength, it is about the quality of sensory information feeding into your nervous system. Toes provide some of the most detailed ground-contact data your brain receives.
What Happens When Toes Are Lost
The clearest evidence for how much toes matter comes from studying people who have lost them. A scoping review of partial foot amputations found that even losing individual toes produces measurable gait changes. Losing the big toe specifically caused a loss of push-off power in both the forward and lateral directions. As the level of amputation moved further back, from individual toes to the metatarsal joints and beyond, the problems compounded: decreased walking speed, reduced stability, and substantial losses in ankle power generation.7British Journal of Sports Medicine. Association between the level of partial foot amputation and gait: a scoping review with implications for the minimum impairment criteria for wheelchair tennis
A case study of a person who had lost multiple toes found that the body compensated by placing greater force on the opposite leg, creating a measurable asymmetry between limbs. That kind of compensatory loading raises the long-term risk of joint problems, particularly osteoarthritis in the knee and hip of the overworked side.8PubMed Central. Compensatory gait mechanics in person with multiple toe amputation: A single case report Another analysis of a young man with bilateral partial toe amputation found that the gait changes looked like stabilizing adaptations driven partly by a fear of falling, and that wearing shoes improved his walking patterns compared to going barefoot.9Biomedical Human Kinetics. Kinematic gait analysis of a young man after amputation of the toes Shoes gave the forefoot a broader, stiffer surface to push off from, partially compensating for the lost toe function.
These findings have practical significance for surgical decisions. When a severely injured hand needs a new thumb, surgeons sometimes transplant a toe to the hand. A review of functional outcomes after such transfers found that about a quarter of cases involving great toe donation resulted in some degree of gait impairment, while second-toe transfers had a lower rate of about 15%.10Annals of Plastic Surgery. Functional Donor Site Morbidity After Vascularized Toe Transfer Procedures: A Review of the Literature and Biomechanical Consideration for Surgical Site Selection Surgeons weigh these trade-offs carefully: the hand’s need for a thumb against the foot’s need for its toes.
Falls Risk in Older Adults
As people age, toe strength declines along with the rest of the body’s musculature. This decline has real consequences. In a prospective study of older adults, those who fell during a 12-month follow-up had significantly weaker toe flexor muscles than those who did not fall. The fallers were also more likely to have hallux valgus (bunions) and lesser toe deformities. Having hallux valgus more than doubled the risk of falling.11PubMed. ISB Clinical Biomechanics Award 2009: toe weakness and deformity increase the risk of falls in older people
A separate prospective study confirmed the pattern: fallers had decreased toe strength, reduced ankle flexibility, and impaired plantar sensation compared to non-fallers. When researchers controlled for age and other known risk factors, decreased toe plantarflexor strength and disabling foot pain remained independently associated with falls.12The Journals of Gerontology: Series A. Foot and Ankle Risk Factors for Falls in Older People: A Prospective Study Grip force of the dominant foot has also been identified as a fall risk factor in community-dwelling older adults.13PubMed Central. Toe grip force of the dominant foot is associated with fall risk in community-dwelling older adults: a cross-sectional study
An interesting wrinkle is that toe deformities do not always show up in standard gait tests. One study found that older people with hallux valgus or lesser toe deformities walked at similar speeds and showed similar postural sway to those without deformities, yet their forefoot pressure patterns were clearly altered.14PubMed. Gait, balance and plantar pressures in older people with toe deformities The problem may not be that the person walks more slowly or sways more in a lab, but that the altered pressure distribution makes them less able to recover from a sudden perturbation, like stepping on a loose rug or shifting weight on a slope. The link between toe problems and falls, in other words, could be about resilience under unexpected stress rather than everyday steadiness.
The Evolutionary Story
Human toes are the product of millions of years of trade-offs. Our distant ancestors had feet built for gripping tree branches, with a widely splayed, opposable big toe much like a chimpanzee’s. A framework for understanding how the human foot evolved describes three broad stages: first, a great-ape-like foot adapted for life in the trees but with some capacity for bipedal walking; second, a foot built for effective two-legged walking that still retained some grasping ability; and third, the modern human foot, optimized for long-distance walking and running, which had lost its prehensility entirely.15Journal of Experimental Biology. Rethinking the evolution of the human foot: insights from experimental research
That evolutionary history helps explain why the big toe is so biomechanically central. In chimpanzees, the medial (inner) side of the foot and the first toe bear disproportionate loads during vertical tree climbing. Peak pressures on the big toe during climbing are higher than during any other type of locomotion chimps perform.16Journal of Human Evolution. Foot use during vertical climbing in chimpanzees (Pan troglodytes) When our ancestors came down from the trees, that medially loaded foot was repurposed for push-off during walking rather than grip during climbing. The big toe lost its ability to oppose the other toes but kept its position as the primary force-bearing digit.
Modeling studies comparing human and non-human ape feet during simulated bipedal walking have found that while both carry similar overall joint forces, human foot proportions produce lower torques in the metatarso-phalangeal joints. Total mechanical work in those joints is lower in human feet than in ape feet, meaning our toe layout is more energy-efficient for walking.17PubMed Central. Analysis of joint force and torque for the human and non-human ape foot during bipedal walking with implications for the evolution of the foot In other words, our shorter, straighter, non-grasping toes are not a downgraded version of an ape foot. They are a different design, tuned for efficient forward locomotion rather than branch-gripping.
What Shoes Do to Toe Function
If human toes evolved for barefoot walking and running, it is worth asking what modern footwear does to them. The answer, across several lines of evidence, is that shoes reshape the forefoot over time. People who grow up habitually barefoot have wider forefeet, greater spacing between the big toe and the second toe, and a smaller hallux angle (the inward drift of the big toe toward the other toes) compared to people who regularly wear shoes.18PubMed Central. Foot Morphological Difference between Habitually Shod and Unshod Runners The most pronounced differences are in the forefoot, where the toes have been compressed by a narrow toe box or left free to splay naturally.19Journal of Biomimetics, Biomaterials and Biomedical Engineering. Analysis of Foot Morphology in Habitually Barefoot Group
Hallux valgus, the condition commonly known as a bunion, is the most visible consequence. Finite element modeling has shown that simulated shoe-wearing conditions concentrate stress on the medial capsule of the big-toe joint, even when the joint starts in a perfectly aligned position.20PubMed Central. The Role of Footwear in the Pathogenesis of Hallux Valgus: A Proof-of-Concept Finite Element Analysis in Recent Humans and Homo naledi Over time, that stress drives the big toe further out of alignment. A twin study found that regularly wearing shoes with a constrictive toe box during the fourth decade of life nearly tripled the odds of developing hallux valgus.21PubMed. Hallux Valgus, By Nature or Nurture? A Twin Study Even occasional use of constrictive toe-box shoes has been linked to changes in hallux anatomy starting at a young age, including increased angulation and bony growths on the toe that appear to result from friction against the shoe.22PubMed. Hallux anatomy: much ado about shoes-an attempt to prove that constrictive V-shaped toe-box shoes deform the hallux
This matters for the balance and gait discussion covered earlier, because hallux valgus is one of the independent risk factors for falls in older adults. The chain of events is straightforward: narrow shoes push the big toe out of position over decades, the deformed toe generates less effective push-off force and altered pressure patterns, and the person becomes more vulnerable to a fall. It is a slow-motion biomechanical degradation that starts with shoe choice and ends with injury risk.
Toes and Athletic Performance
Given how central toes are to walking, you might expect toe strength to be a major predictor of athletic ability. The picture is more nuanced than that. In athletes, toe-pushing force (the ability to press the toes into the ground) was correlated with better agility test performance, specifically in the pro-agility and 3-cone drill. But toe-flexor strength measured by a grip dynamometer did not show the same relationship.23PubMed Central. Relationship Between Toe Muscular Strength and the Ability to Change Direction in Athletes Neither measure predicted straight-line sprint speed. The practical interpretation: toe force matters more for cutting and changing direction than for running fast in a straight line.
At the highest levels, the relationship between toe-joint mechanics and sprinting becomes more interesting. In high-level athletes, the flexion torque at the metatarsophalangeal joint, combined with foot stiffness and reactive strength, explained a meaningful portion of the variance in vertical impulse and contact time during maximal-speed sprinting.24PubMed. Human foot muscle strength and its association with sprint acceleration, cutting and jumping performance, and kinetics in high-level athletes So at top speed, toe-joint mechanics do contribute to how effectively the foot transmits force during the very brief ground-contact window. A small training study that successfully increased participants’ toe-flexor strength by about 16% over a training period found no significant improvement in sprint times or jump heights, though.25Journal of Trainology. Influence of increases in toe-flexor strength on sprint and jump performances Stronger toes alone may not move the needle on gross athletic outputs; the relationship is likely part of a larger system involving ankle stiffness, tendon properties, and neuromuscular coordination.
The Muscles Behind Toe Strength
When you grip with your toes, the force comes from a combination of small muscles within the foot (intrinsic muscles) and larger muscles in the lower leg whose tendons run down into the toes (extrinsic muscles). MRI-based analysis has shown that the major determinant of overall toe-flexor strength is the cross-sectional area of the medial plantar intrinsic muscles, a group that includes the flexor hallucis brevis, flexor digitorum brevis, quadratus plantae, lumbricals, and abductor hallucis.26PubMed Central. Maximum toe flexor muscle strength and quantitative analysis of human plantar intrinsic and extrinsic muscles by a magnetic resonance imaging technique In plain terms, the small muscles right in the sole of your foot matter more to toe grip than the bigger calf muscles do.
This has practical implications for foot health. The intrinsic muscles of the foot are among the most neglected in typical fitness routines. People strengthen their calves, their quads, their glutes, but rarely think about the muscles inside their feet. Yet these are the muscles that stiffen the arch, grip the ground, and power the toe-off. Some physiotherapists have started incorporating “short foot” exercises and towel-scrunching drills into rehabilitation programs for flat feet, plantar fasciitis, and fall prevention in older adults, targeting exactly these small plantar muscles.
Teaching Robots to Walk With Toes
Perhaps the most unexpected confirmation that toes matter comes from robotics. Engineers designing prosthetic legs have traditionally focused on the knee and ankle joints, treating the foot as a passive blade or plate. But a robotic leg prosthesis designed at the University of Michigan replicated the biomechanical functions of the knee, ankle, and toe in a single device. A single motor powers both the ankle and the toe joint through an underactuated mechanism, and the result is revealing: because the biological toe dissipates energy while the biological ankle injects it, the robotic system can regenerate substantial mechanical energy by exploiting that interplay. The device matched the weight, size, and battery life of conventional microprocessor-controlled prostheses while replicating key gait biomechanics more faithfully.27PubMed Central. A lightweight robotic leg prosthesis replicating the biomechanics of the knee, ankle, and toe joint
The engineering insight here is that the toe is not just a passive endpoint. It plays an active role in the energy cycle of walking, absorbing energy at certain phases and allowing the ankle to recover some of that energy. When prosthetic designers ignored the toe, they had to compensate with larger motors and batteries at the ankle. When they included a toe joint, the system became more efficient. Evolution arrived at the same solution a few million years earlier, but it is satisfying to see robotics confirm the logic from a completely different direction.