Application of the ActiGraph GT9X IMU for the assessment of turning during walking and running

Abstract

Objective. The primary purpose of this study was to examine the use of the ActiGraph GT9X gyroscope and magnetometer for turn detection and quantifying turn degree during walking and running. The secondary purpose was to examine the effect of varying turn degrees during walking and running on oxygen consumption. Approach. Participants (N=17) completed pivot trials, straight-line treadmill walking and running (3-6 mph) and four turn conditions (45°, 90°, 135°, and 180°) during overground walking and running. Pivot trials were completed for 1 min and walking/running trials were completed for 6 min, both with a turn frequency of 10 turns/min. Data were collected using a GT9X device (right hip) and a Cosmed K4b 2 (measured oxygen consumption). Raw GT9X gyroscope and magnetometer data were processed through various low-pass filter frequencies (0.25-2.0 Hz). Treadmill and pivot trials were used to develop thresholds for turn detection using gyroscope and magnetometer data and cross-validated using the over-ground trials. Linear mixed models were used to compare actual and estimated number of turns, measured and estimated turn degree, and differences in VO 2 across walking and running speed and turn degree. Main results. Greater than 98% of turns were detected when using gyroscope data filtered at 0.25 Hz and turn degree was estimated within 2.2°of measured turn degree across all speeds. In general, the VO 2 of walking and running increased as the turn degree increased beyond 135°. Significance. The GT9X gyroscope, when filtered at 0.25 Hz can be used to detect the number of turns and estimate turn degree. The magnetometer, when filtered at 0.75 Hz, was useful for detecting the number of turns, however turn detection was more accurate using the gyroscope.

The use of inertial measurement units for analyzing change of direction movement in sports: A scoping review

“…54,55,59,81 19 studies included a combination of two or more COD angles ranging from 45 to 360 . 35,37,39,48,50,52,56,[61][62][63][64][65][78][79][80]84,85,90 Quality assessment. The quality assessment results for all validity/reliability studies is presented in Appendix 3.…”

“…49 In 10 studies, the age of participants was not reported. 38,51,52,[84][85][86][87][88][89][90] The population in studies was most often males. 24 studies included only male participants.…”

“…[35][36][37]39,50,53,54,[56][57][58][59][60][61][62][63]65,67,68,72,73,75,79,85,87 Seven studies had only female participants, 49,52,64,76,77,80,83 11 had both males and females 47,48,51,55,66,[69][70][71]78,89,90 and in 7 the sex was not reported. 38,74,81,82,84,86,88 The background of the population was varying. 24 studies did not specify the sport or background of participants.…”

“…24 studies did not specify the sport or background of participants. 35,38,39,47,48,50,51,53,54,[57][58][59][65][66][67][69][70][71]78,82,84,86,87,90 Eight studies were focused on basketball, 37,52,56,[61][62][63]72,73 six on soccer, 36,49,68,74,77,79 three on netball 76,80,89 and two had multiple sports (hockey, football, rugby, and/or tennis), 55,60 or rugby. 75,81 Study settings.…”

“…playing court, dancehall), 37,50,55,56,[61][62][63][64]68,72,73,76,80,82,83,85,89 nine on outdoor fields 35,38,39,49,74,75,78,81,86 and two both indoors and outdoors. 60,84 In eight studies, there was no mention of study settings. 51,65,66,69,71,79,87,88 Type of COD was anticipated in 33 studies 35,36,38,39,47,48,[51][52][53][54][55][56][57][58][59][6...…”