Obesity and walking

Obesity and walking describes how the locomotion of walking differs between an obese individual (BMI ≥ 30 kg/m2) and a non-obese individual. The prevalence of obesity is a worldwide problem. In 2007–2008, prevalence rates for obesity among adult American men were approximately 32% and over 35% amongst adult American women. According to the Johns Hopkins Bloomberg School of Public Health, 66% of the American population is either overweight or obese and this number is predicted to increase to 75% by 2015. Obesity is linked to health problems such as decreased insulin sensitivity and diabetes, cardiovascular disease, cancer, sleep apnea, and joint pain such as osteoarthritis. It is thought that a major factor of obesity is that obese individuals are in a positive energy balance, meaning that they are consuming more calories than they are expending. Humans expend energy through their basal metabolic rate, the thermic effect of food, non-exercise activity thermogenesis (NEAT), and exercise. While many treatments for obesity are presented to the public, exercise in the form of walking is an easy, relatively safe activity. Walking may initially result in reduced weight, but adopting the habit over the long term may not result in additional weight loss. Knee osteoarthritis and other joint pain are common complaints amongst obese individuals and are often a reason as to why exercise prescriptions such as walking are not continued after prescribed. To determine why an obese person might have more joint problems than a non-obese individual, the biomechanical parameters must be observed to see differences between obese and non-obese walking. Numerous studies have examined the differences in stride between obese and non-obese individuals. Spyropoulos et al. in 1991 examined stride length, width, and joint angle differences between the two groups. They found that obese individuals take shorter (1.25 m vs. 1.67 m) and wider (0.16 m vs. 0.08 m) strides than their non-obese counterparts.