基于点云的运动数据采集平台在评估足踝多关节运动中的应用研究

Application of the point cloud-based motion data acquisition platform in evaluation of foot-ankle multi-joint motion

目的分析自主研发的基于点云的足踝运动数据采集平台采集正常足踝部多关节在运动中的关节角度变化。方法使用基于点云的足踝运动数据采集平台对招募的12位年轻健康受试者分别进行左足和右足步态站立相的数据采集测试,然后根据点云足部分析模型将足部进行多节段分割以配对出后足关节、前足关节、趾关节、中足关节,计算各关节的角度变化。结果后足关节在站立相早期呈跖屈、内收和内翻的状态,随后均在末期发生改变。矢状面上,前足关节在站立相末期跖屈运动;而在冠状面上可以观察到前足关节内翻,但是内翻程度逐渐减小。趾关节的最大变化来自矢状面:先出现大程度的背屈运动,然后不断减小,直至末期又增加背屈。而中足关节由于跗骨关节韧带的约束机制导致其在步态站立相早期和中期的关节角度运动范围比较小。结论基于点云的足踝运动数据采集平台能够对步态中足踝部多关节角度变化数据进行采集和分析,后足关节在各视角平面下的旋转角度变化相对复杂,且趾关节在矢状面下的背屈运动幅度较大。

ObjectiveTo evaluate our self-developed markerless foot and ankle motion data acquisition platform in collecting and analyzing the joint angle changes of normal multiple foot and ankle joints during gait.MethodsTwelve young healthy subjects were recruited for data collection during the stance phase at the left and right foot gait respectively using our self-developed point cloud based foot and ankle motion data acquisition platform.After the foot was segmented into multiple segments according to the point cloud foot analysis model(PFAM)proposed by the present study,a total of 4 joints were paired:the rearfoot joint(shank segment--rearfoot segment),the forefoot joint(rearfoot segment--forefoot segment),the hallux joint(forefoot segment--hallux segment),and the mid-foot joint(rearfoot segment--mid-foot segment).The angle changes of each joint were calculated.ResultsThe rearfoot joint showed metatarsal flexion,adduction and inversion in the early standing phase which then changed at the end of the standing phase.On the sagittal plane,the forefoot joint moved in metatarsal flexion at the end of the standing phase,while the inversion of the forefoot joint was observed on the coronal plane,but the degree of inversion decreased gradually.The largest change of the hallux joint came from the sagittal plane:massive dorsiflexion movement appeared at first and continued to decrease but increased at the end.For the mid-foot joint,the angular range of motion(ROM)was relatively small due to the constraint mechanism of the tarsal joint ligament during the early and middle phases of standing gait.ConclusionsThe point cloud-based foot and ankle motion data acquisition platform can collect and analyze the data of multi-joint angular changes of the foot and ankle during gait.The rotational angular changes of the hindfoot joint are relatively complex on all view planes.The dorsiflexion motion of the lesser toe joint is note-worthy on the sagittal plane.