O uso do acelerômetro ActiGraph® GT3X para avaliação dos saltos verticais: evidências de validação

Abstract

Several scientific publications focus their questions on an important neuromuscular function, potency. Muscle power is the ability of the muscle to produce force in a short period of time. This skill is a fundamental part of the athletic performance of several sports. In the last decades, several methods were created to quantify the muscle power of the lower limbs, making it possible to access the athletic profile considering this physical capacity. Accelerometers are widely used to determine the level of physical activity and sedentary time, and Actigraph® is a renowned brand, however, they can be used for other purposes. Since it is a device that measures acceleration, it becomes possible to use it to calculate the speed, force and power of a movement. The gold standard equipment for this type of evaluation is a force platform. Therefore, the present study analyzes the correlation and concordance between the two methods of measuring lower limbs’ power, evaluating athletes from different modalities, using both equipment simultaneously. For this initiative, the Squat Jump (SJ) and Countermovement Jump (CMJ) tests were selected. Forty-two athletes were evaluated, with a mean age of 22.40±5.8 years, mean body mass of 82.45±19.99kg and mean height of 1.78±0.077cm, divided into three sports modalities, athletics (n = 16), basketball (n=12) and football (n=14). The results of relative power (W/kg) for the force platform and accelerometer in the SJ of each modality and the whole group were respectively: Athletics - PLAT= 93.86±14.32W/kg and ACEL= 94.16±14,14W/kg, Basketball – PLAT= 87.79±6.94W/kg and ACEL= 88.06±6.54W/kg, Football – PLAT= 76.68±14.94W/kg and ACEL= 75, 71±15.20W/kg and the whole group – PLAT= 86.4±14.60W/kg and ACEL= 86.16±14.84W/kg. For the CMJ, the following results were found: Athletics - PLAT= 96.19±14.51W/Kg and ACEL= 96.46±14.52W/kg, Basketball – PLAT= 88.86±6.63W/kg and ACEL= 86.69±6.65W/kg, Football – PLAT= 77.65±14.35W/kg and ACEL= 78.06±14.68W/kg and the whole group – PLAT= 87.93±14, 72W/kg and ACEL= 88.46±14.81W/kg. After completing the descriptive and inferential statistics, high correlation (Pearson) was found between the methods, for all groups in both types of jump (Athletics, SJ r=0.994 and CMJ r=0.993, Basketball, SJ r=0.987 and CMJ r=0.981, Football, SJ r=0.992 and CMJ r=0.998 and All, SJ r=0.993 and CMJ r=0.997). Statistical agreement (Bland-Altman) was also found for the SJ in all groups (Athletics, p=0.447, Basketball, p=0.438, Football, p=0.073 and All, p=0.454), whereas for the CMJ agreement was found only for the athletics and football groups (Athletics, p=0.540, Basketball, p=0.049, Football, p=0.179 and All, p=0.005). The results suggest validation efficacy for the evaluation of the muscle power of the lower limbs with vertical jumps using the Actigraph® GT3X accelerometer, with reservations to be observed in the CMJ, due to inconsistencies in data capture.