Influência da velocidade do andar sobre a mecânica articular dos membros inferiores em crianças obesas

Abstract

The obesity is a dysfunction that is increasingly concerned with its indexes in Brazil and in the world. Population research has registered an alarming increase in the incidence of obesity in Brazil, some surveys indicate that more than 50% of the population is overweight. Obesity is a chronic and interrelated disease directly or indirectly with other pathological situations. Clinically, obesity is associated with numerous health problems. Excess weight is also associated with orthopedic problems due to overload in the musculoskeletal system, is an important contributor to the development of knee varus / valgus in children and associated with increased risk of osteoarthritis of the knee. Overweight and obese children tend to remain obese in adulthood and are more likely to develop comorbidities at earlier ages. For the biomechanical analysis it is necessary to describe and calculate the forces that produce the movement. The moment of strength characterizes the sum of the forces of muscles, tendons, ligaments and bones that are acting internally to counter external forces acting on our body. The objective of this study was to analyze the articular moments in lower limbs of obese children during walking at different speeds. The study group consisted of 16 individuals, aged 8 to 10 years, male and / or female, volunteers, Being divided into two subgroups: overweight group and normal weight group. To evaluate the average speed, Cefise brand photocells were used, the fast speed was established as 30% above the average value of the selected auto speed. For gait evaluation, the VICON three-dimensional cinemetry system (model 624, Oxford, UK) was used with the VICON NEXUS 1.8.5 software. This system consists of seven infrared cameras (MX cameras) that operated at a frequency of acquisition of 200 Hz, recognizing in real time the reflective markers of 14 mm of diameter positioned in the subject, using the model in. For the acquisition of the kinetic data, two AMTI OR6-6-2000 force platforms (Advanced Mechanical Technologies, Inc.) were used, with a sampling rate of 200 Hz. The kinetic data were collected synchronously to the kinematic data for the calculation Of the resulting articular moments. The results revealed that individuals walking at rapid speed showed a significant increase in hip flexion, knee extension and abduction moment peaks and dorsiflexion. It is concluded that walking speed interferes in the joint mechanics, specifically in the articular moments, of the lower limbs of children. It was observed that walking at a rapid rate increases joint moments and with increasing peaks of joint moments, there may be an increase in joint load, and a higher risk of injury in overweight children.