A Study Of Lower-extremity Kinematics In Rumba Forward Walks

Purposes: Through collecting lower-extremity kinematic data of different subjects performing the forward walks of rumba,this study aimed to reveal the basic movements,as well as their technical characteristics and intrinsic patterns of rumba;understand how theangularmovements ofeach jointwerecompletedandcollaboratedwhenbasic techniqueswere performed;compare the differences generated by different subjects;identify the technical specifications;and thus provide a basisforeffectivelyguidingrumbalearnerstopracticeforwardwalksandforinstructorsteaching.Methods: In this study,methods of literature review,experimental research and data treatment were employed to analyze the lower-extremity kinematics of 10 female Latin dancers performing forward walks.The subjects were divided into the experimental group(comprised of 5 professional dancesport students)and the control group(comprised of 5amateur dancesport students).The commonly used Betty Latin dance shoes with 7.5 cm heel height were selected to perform the experiment.The Vconi 3D motion capture system was employed to collectthe lower-extremity kinematic data ofsubjects performingthe movements offorward walks,coupledwiththe employmentof Kistler3 D forceplate measuring groundreactionforcestartingfrom20 N.Astatisticalanalysisofdatawasfinallyperformedusingthe SPSS17.0.Results: Significant differences(P<0.01)in terms of the hip joint range of motion for flexion,abduction,adduction,and medial rotation in the sagittal plane were exhibited when subjects from experimental and control groups were performing forward walks.Specifically,the peak flexion angles and the joint ranges of motion at the sagittal plane were higher in the experimental group than those in the control group.In the coronal plane,the experimental group presented higher peak adduction angles and joint ranges of motion than the control group,while the peak abduction angles of the formerwerelower.Inthetransverseplane,the peak medialandlateralrotationanglesoftheexperimentalgroupwerelower than those of the control group.Significant differences(P<0.01)in terms ofknee joint peak angles and ranges of motionfor flexion,extension,adduction andmedial rotation inthe sagittal plane were exhibitedby subjects performingforward walks.Specifically,the peak flexion angles and joint ranges of motion of the experimental group were higher.than those of the control group,while the peak extension angles of the former were lower.In the coronal plane,the peak knee adduction angles of the experimental group were higher.than those of the control group,while the knee ranges of motion of the former were lower.In the transverse plane,the knee joint's peak medial rotation angles of the experimental group were lower than those of the control group,while the knee joint ranges of motion of the former were higher.Significant differences(P<0.01)in terms of the ankle range of motion in the coronal plane,as well as in peak medial rotation angles and joint range of motion in the transverse plane were exhibited between experimental and control groups,with the peak anklemedialanglesoftheexperimentalgrouplowerthanthoseofthecontrolgroup.Conclusions:1.Significantdifferences inkinematic characteristics exhibitedbylowerextremities,such asthe hip,knee and ankle joints,were found between subjects of experimental and control groups when performing rumba forward walks.In particular,the variations in peak angles of hip and knee joints were most evident.2.The control group had better results in terms of opening degree and flexibility of hip than the experimental group.3.Neither excessively higher or lower joint motion of range facilitates the mastery and perfection of movements,and the angles of hip,knee and ankle joints during different time phases need to be fully mobilized and brought into coordinated development.It is recommended that the extremitymovementsbedrivenintotheirlimitstocreateaestheticdancingmovementsduringqualitytraining.