Wearing shoes that are a bit too tight won't permanently harm kids, say experts on proper footwear for children, adults and the elderly, but crowding the toes will damage adult feet.
Women who regularly wear high heels, and older people who walk around in slippers, are putting their health at risk, warned Robert Roedl, head of the Department of Paediatric Orthopaedics, Deformity Reconstruction and Foot Surgery at Germany's Muenster University Hospital.
Most children wear ill-fitting shoes much of the time, yet they manage to play and romp around with both too much and too little toe room.
"About two-thirds of children's shoes are the wrong size, the majority being too small," said Dr Roedl.
Kids generally wear a pair of shoes for one season. Parents would need to replace the footwear more often to ensure the fast-growing feet are always in properly fitting shoes, Roedl said.
"In effect, kids' footwear is too small half the time."
Parents who buy children's shoes annually needn't worry, though. Roedl said there were no complications from slightly tight children's shoes.
But in the case of adults, while pointed-toe shoes and high heels may look great, they're unhealthy for the feet.
"If you constantly walk on your toes, you'll end up with deformed feet, warned Dr Karl-Dieter Heller, vice president of the Berlin-based Professional Association of Orthopaedics and Trauma Surgery.
In effect, kids' footwear is too small half the time.
According to a 2012 study by the Orthopaedics Department of Germany's Tuebingen University Hospital, up to 23 per cent of people aged 18 to 65 have a hallux valgus deformity, or bunion.
It is often described as a bump on the side of the big toe, which ends up leaning towards the second toe rather than pointing straight ahead. This often crowds the other toes in the shoe's toe box, making them bend upwards and rub against the shoe, causing pain.
The condition is most common in women who regularly wear high heels. The reason is that the Achilles tendons of some high-heel wearers thicken and lose flexibility, scientists from the universities of Manchester and Vienna have found.
Meanwhile, improper footwear on the elderly can be life-threatening. While slippers are comfortable and easy to put on, they provide no support and facilitate falls.
"You can definitely assume a heightened risk (of falling)," said Dr Kilian Rapp, a senior physician in the Geriatric Rehabilitation Clinic at Robert Bosch Hospital in Stuttgart.
In 2014, he and his colleagues analysed more than 70,000 falls in some 530 nursing homes in Bavaria. One finding: "Falls in slippers resulted more frequently in serious injuries."
"Falls are one of the biggest problems in old age," Rapp said.
Broken bones are especially serious for the elderly. According to the North Rhine Medical Association, about a third of very elderly patients die within a year of having in-patient treatment for a hip fracture, and about half never regain their prior mobility.
A European Commission-funded initiative called the Prevention of Falls Network for Dissemination warns older people against walking around in socks, high shoes or poorly fitting slippers without heel support.