The Analysis On The Joint Angles Of Lower Limbs Of Brisk Walking From The Sagittal And Coronal Plane At Different Slopes

Objective: As the world's physical exercise craze continues to rise,brisk walking is welcomed because of its easiness and remarkable effect.Therefore,the analysis of the characteristics of joint angles of lower limbs from the sagittal and coronal plane under different exercise conditions(uphill or downhill)has important significance for exercise and prevention of sports injuries.Methods: VICON infrared 3D motion analysis system was used to monitor 20 adult male subjects when they did the brisk walking.The subjects completed the fast walking at 6km/h with the slopes being 0%?+ 7%?+ 10.5%?+ 14.1%?-7%?-10.5% and-14.1% respectively,and the test interval is 2 minutes.Ten continuing steps of each stage is selected as a data analysis unit.With the Vicon Nexus 2.3 software of the Plug-in Gait Dnamic model,interrelated data of the joint angles of the ankle,knee and hip in the sagittal and coronal planes were collected.Finally,SPSS was used to analyze the data of the joint angles of lower limbs under different slopes.Results: The results showed that in one gait cycle,the sagittal joint angle of the ankle varied from 73 ° to 107 °.There was a significant difference about plantar flexion and dorsiflexion whit different slopes(P <0.00).With slope angle increasing(-14.1% ~14.1%),the degree of plantar flexion extended gradually(the angle of joint changed from 84.7° to 90.2 °),the degree of dorsiflexion went up as well(the angle of joint increased from 72.6 ° to 78.7 ° Variety).There was a significant difference among the peak values of ankle joint angle in sagittal pane under different slope conditions during the supportive period(P <0.00).In the process of supporting,the degree of ankle valgus decreased from-14.1% ~ 14.1%,while joint angle varied from 1.6 ° ~ 3.8 °).The values of pronation increased with the decrease of the gradient(the joint angle changed from-1.7 ° to-2.7 °).The change of gradient has a great effect on knee joint angle.As for the starting point,the minimum value and the peak value when leaving the ground,and thefalling point,the minimum value and the peak value when supporting,there is a significant difference about knee joint sagittal angle with different slopes,P <0.05.Among them,it is at the-14.1% gradient that the maximum sagittal angle of knee(69.3 °)appeared,and the minimum sagittal angle(49.1 °)responding to 14.1%gradient.At the same time,the degree of knee flexion increased with the steepness becoming large,concretely speaking,the joint angles decreased from 154.8 °to 150.4 °and from 154.6 °to 151.1 ° respectively,corresponding to the gradient arranged from-7% to-14.1% and from 0% to 14.1%.while the degree of knee extension rose as the slope increased from-14.1% to14.1%,joint angle changed 170.5 ° to 176.8.Knee joints of the coronal joint angle maintained a certain degree of valgus at different slopes,and the significant difference appeared among the peak values(P <0.00).The valgus occurred uphill and downhill,it is more obvious of downhill.The valgus angle was12.5 ° at-14.1% slope,and 10.4 ° and 9.4 °corresponding to 0% and 14.1%,respectively.The change of gradient had a significant effect on the hip joint sagittal joint angle(P <0.00),but the regularity of change was not obvious.Conclusions: The change of slope has a significant effect on the joint angle of sagittal and coronal plane of the ankle,knee joint,hip during fast walking.Fast walking under downhill conditions makes the valgus degree of plantar flexion increased significantly,the risk of sports injuries also rises up,and joint injuries occur more commonly;and the fatigue of the calf muscles arises uphill.In the fast walking,the steep gradient get larger,the greater the degree of knee flexion,knee extension changes with the rise of the slope,the relevant control muscle and ligament comes out fatigue damage.The increase of downhill gradient causes the valgus degree of knee joint intensity,the decrease of knee joint stability reveals,ligament or junction of joint is hurt easily,and the incidence of downhill injury occurs more than that of uphill.