Excessive Weight Bearing Compromises Foot Structure and Function Across the Lifespan - The Mechanobiology of Obesity and Related Diseases - page 163

measure plantar pressures (e.g. capacitive pressure distribution platforms of varying
resolution [ 85 , 93 , 118 ] versus in-shoe pressure measurement systems [ 106 , 110 ]).
Just because an individual is obese does not mean they will have high foot
pressures [ 106 ]. Numerous other factors such as lower extremity biomechanics,
foot type, and the presence of foot deformities are likely to have more influence on
the peak pressures generated on the plantar surface of the foot than body mass in
isolation. All else being equal, however, increased body mass can exacerbate areas
prone to high plantar pressures, and possibly contribute to foot discomfort and
pain. Ease of walking, as determined by foot discomfort, may be a major limiting
factor in the predisposition of obese individuals to participate in habitual physical
activity such as walking [ 85 ], and ultimately perpetuate the cycle of obesity as
previously described. Messier et al. [ 96 ] also postulated an association between
poor foot mechanics in adults and the limited involvement by obese individuals in
activities of daily living or exercise regimes. Decreasing an individual's body mass
may be an effective mechanism to reduce foot discomfort and pain, and the risk of
foot disorders including the risk of foot ulceration associated with neuropathy and
high foot pressures [ 106 ]. In support of this notion, reductions in peak plantar
pressures were observed under the midfoot and metatarsal heads in a subset of
overweight participants (6 women and 3 men), who reduced their original body
weight by 20 % (Bolte et al. 2000, cited in Wearing et al. [ 108 ]).
4.4 Older Adults (>60 years)
Like their younger counterparts, the elderly have not escaped the obesity epidemic,
with 15-37 % of men and 28-42 % of women aged over 60 years considered to be
obese [ 119 , 120 ]. As the proportion of elderly people is rapidly increasing and the
negative health consequences of obesity are numerous and well documented [ 121 ],
it is imperative that effective, evidence-based interventions aimed at combating
obesity in the elderly are developed and implemented. Interventions targeted at
overweight and obese older individuals, however, are often confounded because of
the numerous chronic diseases associated with ageing, particularly diseases
affecting the musculoskeletal system such as osteoarthritis and rheumatoid
arthritis, which can limit older people participating in physical activity [ 122 ] and
restrict their mobility [ 123 ]. It is therefore important that we understand how
obesity impacts upon the musculoskeletal structure and function of older indi-
viduals, particularly the feet, so that exercise interventions can be modified to
accommodate for the unique needs of this growing section of the population.