Obesity is a major health issue worldwide affecting approximately 58% of Australian men and women (Walsh & Thomas, 2015). Obesity is defined as having excess adipose tissue with a body mass index (BMI) greater than 30kg/m2 (Frowen, O’Donnell, Lorimer, and Burrow, 2010). Symptoms associated with obesity are can be shortness of breath, sudden death, stroke, and infertility (Faintuch, & Faintuch, 2014). In combination to these symptoms, obesity may lead to many co-morbidities such as type II diabetes, hypertension and hyperlipidaemia and these issues can not only affect foot health, but it can cause detrimental affects on general health and wellbeing. This however is not limited to obese patients and can occur even in people with normal or ‘ideal’ body weight (Crawford, Jeffery, Ball, & Brug, 2010). Type II diabetes and peripheral vascular disease is most relevant to foot health as they affect the lower limb dramatically. Having high stores of visceral fat is often associated with decreased peripheral insulin sensitivity and has been suggested to contribute to hepatic insulin resistance (Gastaldelli et al., 2002). Due to compromised insulin hyperglycemia can effect the nerves causing peripheral neuropathy and poor foot health.
Having a high BMI can increase the risk of putting a higher biomechanical load on joints and muscles. This can potentially lead to many pathologies that affect foot health such as joint pains, reduced fat padding and changes in balance and gait (Tanamas et al., 2012). Studies show that there is a strong correlation between high BMI and musculoskeletal foot pain. However, there is not conclusive evidence solely on the affect on obesity as many co-morbidities associated with obesity can influence foot pain. A systematic review conducted by Butterworth, Landorf, Smith, & Menz (2012) shows that there is strong evidence that a high BMI is associated with chronic heel pain. This chronic heel pain is often associated with plantar fasciitis as patients that are obese often exhibit flatter feet, reduced inversion–eversion range of motion, and higher peak plantar pressures when walking (Butterworth et al., 2015). Studies also show that in adult and adolescent obese populations foot pain is the second most common musculoskeletal symptom, second only to back pain (Butterworth et al., 2013). A theory could be that adipose tissue releases inflammatory mediators which cause changes to connective tissue which supports the structural integrity of the foot (Butterworth, Landorf, Gilleard, Urquhart, & Menz, 2013). With compromised structural integrity of the foot this could cause a multitude of intrinsic issues.