Validation and influence of anthropometric and kinematic models of obese teenagers in vertical jump performance and mechanical internal energy expenditure

There may be concerns about the validity of kinetic models when studying locomotion in obese subjects (OS). The aim of the present study was to improve and validate a relevant representation of obese subject from four kinetic models. Fourteen teenagers with severe primary obesity (BMI=40±5.2kg/m2), were studied during jumping. The jumps were filmed by six cameras (synchronized, 50Hz), associated with a force-plate (1000Hz). All the tested models were valid; the linear mechanical analysis of the jumps gave similar results (p>0.05); but there were significantly different segment inertias when considering the subjects’ abdomen (p<0.01), which was associated with a significantly higher mechanical internal energy expenditure (p<0.01) than that estimated from Dempster's and Hanavan's model, by about 40 and 30%. The validation of a modelling specifically for obese subjects will enable a better understanding of their locomotion.