When people think about strength training, the feet rarely make the list. Quads, glutes, core, shoulders, but tucked inside each foot is a group of small, often-overlooked muscles doing far more work than they get credit for, and neglecting them can quietly undermine everything built on top of them.
These are the intrinsic foot muscles — a group of small muscles that live entirely within the foot itself, distinct from the larger muscles that originate up in the calf and cross into the foot. And a growing body of research shows that strengthening them pays off in ways that ripple well beyond the foot itself.
What These Muscles Actually Do
Foot alignment and muscle function play a central role in stability, balance, and mobility, and the intrinsic foot muscles provide the support that allows the larger, more powerful muscles to produce big movements like walking and running. Think of them as the foot’s stabilizing core, similar to how deep core muscles stabilize the spine before bigger muscles generate force.
This isn’t just a structural role. These muscles also feed into the body’s sensory system. Intrinsic foot muscle strength matters because these muscles form the “foot core” — actively stabilizing the medial longitudinal arch, distributing load, contributing to balance and proprioception, and generating propulsive force with every step. A robust body of research links weakness in these muscles to foot pathology, and strengthening them to measurable functional gains. Research has found that intrinsic foot muscle activation and toe flexor strength are correlated with balance performance, meaning weak or under-active foot muscles don’t just affect how the foot moves — they affect how well the whole body senses its position in space.
What Happens When They’re Weak
A weakened foot core shows up in a surprising number of common complaints:
Plantar fasciitis and heel pain. Research has documented smaller and weaker intrinsic foot muscles in individuals with plantar heel pain, making this muscle group an important clinical target in both assessment and treatment. One study on plantar fasciitis found that intrinsic strengthening led to meaningful improvements across pain, disability, and daily activity limitation.
Flat feet (pes planus). These muscles are essential to supporting the foot’s medial longitudinal arch — the arch along the inside of the foot. Weakness here contributes to arch collapse and the downstream issues that come with it.
Balance problems and falls, especially in older adults. Multiple systematic reviews have found that toe flexor strength contributes to improved postural balance in people over 60, and that older adults who performed intrinsic foot muscle strengthening saw real improvements in both strength and balance. Some studies even found reductions in fall incidence.
Running injuries. A randomized controlled trial found that runners who completed a foot-strengthening program had a lower risk of running-related injuries compared to those who didn’t.
Knee and lower-limb issues. Foot mechanics don’t stay contained to the foot. Clinicians frequently trace knee problems back to what’s happening at the ground — poor foot stability changes how force travels up the chain, placing extra stress on the knee and hip above it.
Why This Matters for Veterans Specifically
Veterans carry particular risk factors that make foot strength worth paying attention to:
- Years of boot-wearing in structured, often rigid footwear can under-stimulate the small stabilizing muscles of the foot, since supportive boots do some of the stabilizing work the intrinsics would otherwise be doing themselves.
- Load-bearing history — years of rucking, running, and carrying heavy loads — creates cumulative stress on the foot and ankle, making a strong foot core more important, not less.
- Aging veterans face compounding risk. Falls and balance issues become a bigger concern with age, and intrinsic foot strength is directly tied to fall-risk reduction in older populations — a genuinely modifiable target rather than an inevitable decline.
- Existing lower-limb injuries common in veteran populations (ankle instability, plantar fasciitis) are specifically named in the research as conditions intrinsic foot strengthening is advocated for.
Getting Started
The appeal of this muscle group is that training it doesn’t require a gym. A few exercises show up consistently in the research and clinical practice:
- Short foot exercise — drawing the ball of the foot toward the heel without curling the toes, creating a “doming” effect in the arch. This is one of the most studied and recommended intrinsic strengthening exercises.
- Toe yoga — practicing isolated toe control, such as lifting only the big toe while pressing the other four down, then reversing it. This builds the fine motor control and mind-muscle connection that make the other exercises more effective.
- Toe spreading and lifting — actively spreading the toes apart, or lifting just the big toe while keeping the others down, which builds the fine motor control these muscles are responsible for.
- Barefoot time, when appropriate and pain isn’t a limiting factor — going barefoot on safe surfaces allows the small foot muscles to engage in ways supportive footwear doesn’t require them to. Walking barefoot on sand is a particularly effective version of this, since the unstable surface forces the small stabilizing muscles to work harder with every step.
Research suggests around eight weeks of consistent foot strengthening is typically needed to see measurable improvements in balance, so this isn’t a one and done fix, it’s a habit worth building the same way you’d build any other strength program.
The Bottom Line
The intrinsic foot muscles are easy to ignore precisely because they’re small and hidden inside the shoe. But they’re foundational — literally, the base everything else stands on. Whether the goal is resolving persistent heel pain, protecting aging joints from falls, or simply building a more resilient foundation for walking, running, and rucking, strengthening these small muscles is a high-value, low-cost addition to almost any exercise program.
This information is for general educational purposes. Anyone with persistent foot or heel pain, a diagnosed foot condition, or balance concerns should consult with a physical therapist for an individualized evaluation and exercise plan.
Leave a Reply