Author(s): TANG, Z.1, LIU, J.2, LIU, Y.2, Institution: SOUTHEAST UNIVERSITY, Country: CHINA, Abstract-ID: 1837

INTRODUCTION:
Locomotion with body borne loads may change the kinematic characteristics of human body, and further impairing exercise performance of human body. During uphill walking,the body needs to do extra work against gravity,the inclined plane also effects the posture of the body. However, in the uphill walking, the effect of different loads on joint is not clear. The purpose of this study was to determined the characteristic of peak flexion angle of hip, knee, and ankle during uphill walking with different body borne load.
METHODS:
Ten male subjects were selected. Age range: 23-26 years old; height: 176.6 ± 5.0cm; weight: 71 ± 8.3kg. The load weight is 0kg (none load), 15kg(medium load) and 30kg(heavy load) respectively. The load was put on the subjects in the form of weight-bearing vests, and the weight was evenly distributed in front, back, left and right of the subjects, the test was carried out on a treadmill with a walking speed of 4km/h, the angle of the treadmill is 8 degrees. Participants had biomechanical data recorded during uphill walking. Specific variables include peak flexion angle of joint (hip, knee and ankle), which collected by 8 lens infrared motion capture system (Motion analysis, Raptor-4; USA). We selected the data of three left single steps during support phase walking and take the average value. R 4.2.2 was used to process the analysis data, and repeated measures ANOVA was user to test the effects of load configuration.
RESULTS:
During the uphill walking, peak hip flexion angle was 133.9 ± 6.3, 132.1 ± 8.8 and 138.2 ± 7.1 for the none, medium and heavy loads, respectively. Peak knee flexion angle was 139.2 ± 6.1, 139.9 ± 6.5 and 136.0 ± 6.3 for the none, medium and heavy loads, where the angle of heavy load is significantly lower than that of no load (p = 0.03). Peak ankle flexion angle was 88.8 ± 7.6, 85.7 ± 9.7 and 84.3 ± 8.9 for the none, medium and heavy loads..
Body borne load significantly decreased peak ankle flexion angle (p = 0.012) during the uphill walking. No significant trend were observed in peak hip (p = 0.084) and knee (p = 0.240) flexion angle with load.
The current outcomes suggest that adding body borne load does not significantly shift kinematic characteristic of hip and knee during uphill walking. The findings of ankle and knee are in agreement with previous experimental evidence in flat ground, But the trend of hip is different from their results . The decrease of ankle flexion angle may be to better adapt to uphill movement.
CONCLUSION:
The load carrier adopted a stable biomechanical profile in hip and knee to maintain performance of the uphill walking. Greater weight bearing will result in greater ankle flexion angle.