Effect of obesity on kinematic chain segments of lower extremity in middle aged individuals

Abstract

With the global rise in obesity and increasing rate of musculoskeletal disorders, there is a demand to evaluate the effects of obesity on the various segments of lower quadrant as they function in closed kinematic chain. The pelvic girdle and lower limbs are a part of a long kinematic chain, thus interlinked and interdependent in terms of movements and alignments. Postural changes in the lower extremity may lead to the occurrence of biomechanical alterations in the pelvic girdle and vice versa. Therefore, if normal mechanics of various lower limb kinematic chain segments is interdependent, the malalignments should also be. As body mass increases due to reduced activity and improper dietary intake, it can lead to alteration in the normal biomechanical arrangement of lower limb segments. Various previous researchers have theoretically postulated that increased body weight may lead to more anterior pelvic inclination, with excessive femoral internal rotation, which can raise the quadriceps-angle and tibial medial torsion and ultimately lead to flat foot. With the above background, present study aims to assess the relationship between pelvic inclination angle, quadriceps-angle and navicular drop and the effect of increasing body weight on these segments of kinematic chain of lower extremity. An observational case control study was conducted on 240 subjects divided in 2 groups (120 subjects in each group) on the basis of Asian classification of Body Mass Index, Group A as Normal Weight group (BMI score 18.5 to 22.9 kg/m2 ) and Group B as Obese group (BMI score gt 25 kg/m2 ). Both males and females between 30-50 years were included in the study. A written informed consent was taken from all the study participants. Outcome measures of the study were pelvic inclination angle (PIA), quadriceps-angle (Q-angle) in standing position, navicular drop test (NDT), waist-hip ratio (WHR), body mass index (BMI), average macronutrients and energy intake estimation. On analysis, a significant higher mean values of PIA, Q-angle and NDT