Gaining extra weight has many adverse health consequences, including increased risk for heart disease, type 2 diabetes, osteoarthritis, and a shortened lifespan. One of the first interventions suggested is exercise, and walking, even at a very slow pace, is always recommended.
Sounds simpler than it often is. Chronic foot pain and discomfort can prevent overweight people from doing regular physical activities such as walking. And the way the feet of overweight children develop may put them at higher risk for mobility limitations and poorer health.
When a normal-weight person walks, the feet and joints of the ankle, knee and hip are subject to forces equal to 3 to 6 times their body weight as they stand on one leg and swing the other forward. The heavier a person is the greater the force exerted on their feet and joints. This persistent loading over time results in soreness and discomfort, which may cause a person to alter their normal walking pattern. Toeing-out and heel pain are common in overweight people. So are chronic muscle and joint soreness in the legs and feet, which can lead to progressive loss of mobility, and increased risk for disabilities such as flat feet and osteoarthritis of the knees and hips.
Overweight adults often walk slower and with their feet farther apart because they need a wider base of support for balance and because of the size of their thighs. Gait analysis of overweight subjects show more pressure is exerted on their feet under the heel, at the middle of the foot, and under the toes during walking and even while standing still. This causes both a flatter and fatter footprint as the ligaments in the arch become weakened.
As the incidence of overweight increases in children, many of the foot problems seen in overweight adults are appearing in very young children, too. Infants typically have pudgy, flat feet, but as the arch develops between the ages of 2 and 5, the fat pad at the bottom of the foot thins. The feet of overweight elementary school children are typically flatter and fatter than those of their leaner classmates. Some studies have shown that extra weight will start to affect the shape of a child’s foot as early as preschool.
Gait studies have shown that the flatter, wider feet of overweight children are due to a lowering of the normal arch—the simple result of continually supporting extra weight. It’s been suggested that these early structural changes in children’s feet will only get worse if they stay overweight throughout childhood and into adulthood.
A lot has been written about the health consequences of carrying extra weight. But, the most consistent and obvious problems of pain, discomfort and structural changes in our feet has gotten little attention. Maybe we need to refocus our attention on the overweight epidemic in this country from the ground up.