Anticipatory Postural Adjustments and kinematic arm features when postural stability is manipulated

PeerJ

Cesar Ferreira Amorim¹  Thierry Pozzo²  France Mourey²  Ghislain Saunier³  Manuela Brito Duarte⁴  Gizele Cristina da Silva Almeida⁴  Bianca Callegari⁴  Givago da Silva Souza⁵ 

[1] Doctoral and Masters Program in Physical Therapy, Universidade Cidade de São Paulo, São Paulo, Brazil;INSERM U1093, Cognition Action et Plasticité Sensori-motrice, Université de Bourgogne, Dijon, France;Laboratorio de Cognição Motora, Universidade Federal do Pará, Belém, Brazil;Laboratório de Estudos da Motricidade Humana, Universidade Federal do Pará, Belém, Brazil;Núcleo de Medicina Tropical, Instituto de Ciencias Biológicas, Universidade Federal do Pará, Belém, Brazil;

关键词: Standing;    Sitting;    Antecipatory postural adjutments;    Stability;    Posture;    Surface electromyography;   

DOI  :  10.7717/peerj.4309

来源: DOAJ

【 摘 要 】

Beyond the classical paradigm that presents the Anticipatory Postural Adjustments (APAs) as a manner to create forces that counteract disturbances arising from the moving segment during a pointing task, there is a controversial discussion about the role APAs to facilitate the movement and perform a task accurately. In addition, arm kinematics features are classically used to infer the content of motor planning for the execution and the control of arm movements. The present study aimed to disentangle the conflicting role of APAs during an arm-pointing task in which the subjects reach a central diode that suddenly turns on, while their postural stability was manipulated. Three postures were applied: Standing (Up), Sit without feet support (SitUnsup) and Sit with feet support (SitSup). We found that challenging postural stability induced an increase of the reaction time and movement duration (observed for the SitUnsup compared to SitSUp and Up) as well as modified the upper-limb velocity profile. Indeed, a greater max velocity and a shorter deceleration time were observed under the highest stability (SitSup). Thus, these Kinematics features reflect less challenging task and simple motor plan when the body is stabilized. Concerning the APAs, we observed the presence of them independently of the postural stability. Such a result strongly suggests that APAs act to facilitate the limb movement and to counteract perturbation forces. In conclusion, the degree of stability seems particularly tuned to the motor planning of the upper-limb during a pointing task whereas the postural chain (sitting vs. standing) was also determinant for APAs.

【 授权许可】

Unknown