Are barefoot shoes good for you?

This question deserves a straight answer rather than either reflex, so here is ours: for most healthy adults, yes, with a slow transition — and the specific benefit best supported by evidence is foot strength, not posture, knees or back. For some people the answer is no, and we list them below.

This is the strongest finding in the field. A review of minimalist-shoe studies found significant increases in foot muscle strength, volume, cross-sectional area and thickness, with reported strength gains spanning roughly 9 to 57 percent and size increases of around 7 to 11 percent across studies. One study found the cross-sectional area of the abductor hallucis increased significantly in a minimalist-footwear group over a 10-week protocol compared with a traditional-shoe group.

A randomized trial comparing foot-strengthening exercises against minimal-shoe walking against a control group followed 57 healthy runners with ultrasound at baseline, 8 weeks, 16 weeks and one year — which is a more rigorous design than most footwear research manages. The children's literature points the same way: a randomized trial of minimalist school shoes in primary-school students reported improved intrinsic foot muscle size, strength and arch integrity.

So if someone tells you minimalist shoes strengthen your feet, they are on solid ground. More detail here.

Research on shoe-wearing patterns in older women found that wearing shoes with narrow or very narrow toe boxes between the ages of 20 and 39 increased the likelihood of hallux valgus compared with those who wore very wide toe boxes. Cross-sectional work has associated constrictive toe boxes with hallux valgus and foot pain, and elevated heels with hallux valgus and plantar calluses.

That is good reason to prefer a wide toe box over decades. It is not evidence that a wide shoe reverses a bunion you already have — and in fact one study of older women with painful hallux valgus found that the toe-box shape and fit of their usual footwear was not associated with increased medial forefoot pressures. Prevention and treatment are different questions and the evidence treats them differently.

Posture, balance, knee pain and back pain are where the claims outrun the data. There are plausible mechanisms and enthusiastic testimonials for all four. There is not the kind of controlled, measured evidence that exists for muscle growth. We will not dress that gap up as "research-backed," and you should be suspicious of anyone who does.

The same applies to any claim that barefoot shoes treat a condition. They are footwear. Footwear changes how load travels through your foot, which can help or hurt depending on what is wrong with it.

A 2013 MRI study followed 36 experienced recreational runners for 10 weeks; 19 transitioned gradually into Vibram FiveFingers and 17 stayed in conventional shoes. Ten of the 19 in the minimal group developed new bone-marrow edema in at least one foot bone. Two were diagnosed as stress fractures. The majority were subclinical — those runners had no symptoms. Systematic reviews report moderate evidence that minimalist shoes increase forefoot pressure and metatarsal stress-fracture risk relative to conventional running shoes.

This is not an argument against the shoes. It is an argument against the ramp-up most people choose. Our transition plan is built around it.

• Anyone with reduced sensation in their feet — diabetic neuropathy in particular. Thin soles trade protection for feedback, and that trade only makes sense if you can use the feedback.
• Anyone with an acute foot, ankle or lower-limb injury. Changing mechanical inputs mid-injury is a bad idea regardless of the direction.
• Anyone with a history of metatarsal stress fracture. The loading change targets exactly that tissue.
• Anyone with a stiff, structurally flat foot rather than a weak one. The adaptation these shoes depend on may not be available.
• Anyone currently in pain. Get a diagnosis first. A shoe change is a poor substitute for knowing what is wrong.

If you are in the clear and want the smallest-risk version of this experiment: start with a thicker minimal shoe, keep your current shoes, and add minimal-shoe hours gradually. The picks below are ordered by exactly that logic.