Kinematic analysis and self-perceived exertion during the walking gait with a backpack in Brazilian scholars

Abstract

The present study aimed to investigate the effects of different backpack loads on the walking gait kinematics and ratings of perceived exertion (RPE) in Brazilian scholars. Methods: The sample was composed of 25 male children and adolescents, from 10 to 14 years. The mean body mass and height were 45.3 kg ± 10.6 kg and 1.51 m ± 0.08 m, respectively. For the walking gait assessment, a tridimensional analysis system was used. In the backpack conditions, loads of 5%, 10%, 15%, and 20% were applied according to the body weight of everyone. Kinematic variables and angular amplitudes of head, shoulders, thorax, pelvis, and knees in the sagittal plane were collected. The OMNI scale was used to assess the RPE. Results: The loads of 5%, 10%, 15%, and 20% promoted postural adjustments and alterations in the walking gait, in which the RPE presented a correlation with those alterations. The step in the left cycle altered from the baseline in the 5% (p = 0.006). The stride length altered from baseline in the 5% (p = 0.030) and 10% (p < 0.001) load conditions. The single support time was different from baseline in all conditions (p = 0.003; p = 0.012; p = 0.005; p = 0.006). The walking gait cadence was different in the comparison between baseline in the 5% (p = 0.003). Thorax amplitude altered in the 10% (p = 0.023), 15% (p = 0.033) and 20% (p = 0.005) load conditions in the left cycle. Conclusion: We concluded that the posture, RPE, and the gait kinematic altered according to the increase in the backpack load.