Hip joint centers location from clinical measurements using statistical inference

Obesity in older adults is a growing public health problem. Excess weight causes biomechanical burden to lower extremity joints and contribute to joint pathology. The aim of this study was to identify specific characteristics of gait associated with body mass index (BMI). Preferred and maximum speed walking and related gait characteristics were examined in 164 (50–84 years) participants from Baltimore Longitudinal Study of Aging (BLSA) able to walk unassisted. Participants were divided into three groups based on their BMI: normal weight (19≤BMI<25 kg/m2), overweight (25≤BMI<30 kg/m2) and obese (BMI 30≤BMI<40 kg/m2). Total ankle generative mechanical work expenditure (MWE) in the anterior–posterior (AP) plane was progressively and significantly lower with increase in BMI for both preferred (p=0.026) and maximum speed walking (p<0.001). In the medial–lateral (ML) plane, total knee generative MWE was higher in obese participants in the preferred speed task (p=0.002), and total hip absorptive MWE was higher in obese in both preferred speed (p<0.001) and maximum speed (p=0.002) walking task compared to the normal weight participants. Older adults with obesity show spatiotemporal gait patterns that may help in reducing contact impacts. In addition, in obese persons mechanical energy usages tend to be lower in the AP plane and higher in the ML plane. Since forward progression forces are mainly implicated in normal walking, this pattern found in obese participants is suggestive of lower energetic efficiency.