The literature reports that anticipatory postural adjustments (APAs) are programmed according to movement velocity. However, the linkage between APAs and velocity has been highlighted within single subjects who were asked to voluntarily change movement velocity; therefore, till now, it has been impossible to discern whether the key factor determining APA latency was the intended movement velocity or the actual one. Aim of this study was to distinguish between these two factors. We analyzed the APA chain that stabilizes the arm during a brisk index finger flexion in two groups of subjects: (1) 29 who composed our database from previous experiments and were asked to "go-as-fast-as-possible" (go-fast), but actually performed the movement with different speeds (238-1180°/s), and (2) ten new subjects who performed the go-fast movement at more than 500°/s and were then asked to go-slow at about 50 % of their initial velocity, thus moving at 300-800°/s. No correlation between APA latency and actual movement speed was observed when all subjects had to go-fast (p > 0.50), while delayed APAs were found in the ten new subjects when they had to go-slow (p < 0.001). Moreover, in the speed range between 300 and 800°/s, the APA latency depended only on movement instruction: subjects going fast showed earlier APAs than those going slow (p < 0.001). These data suggest a stronger role of the intended movement velocity versus the actual one in modifying the timing of postural muscles recruitment with respect to the prime mover. These results also strengthen the idea of a shared postural and voluntary command within the same motor act.

Intended rather than actual movement velocity determines the latency of anticipatory postural adjustments / R. Esposti, C. Bruttini, F. Bolzoni, P. Cavallari. - In: EXPERIMENTAL BRAIN RESEARCH. - ISSN 0014-4819. - 233:2(2015 Feb), pp. 397-403. [10.1007/s00221-014-4122-7]

Intended rather than actual movement velocity determines the latency of anticipatory postural adjustments

R. Esposti
Primo
;
C. Bruttini
Secondo
;
F. Bolzoni
Penultimo
;
P. Cavallari
2015-02

Abstract

The literature reports that anticipatory postural adjustments (APAs) are programmed according to movement velocity. However, the linkage between APAs and velocity has been highlighted within single subjects who were asked to voluntarily change movement velocity; therefore, till now, it has been impossible to discern whether the key factor determining APA latency was the intended movement velocity or the actual one. Aim of this study was to distinguish between these two factors. We analyzed the APA chain that stabilizes the arm during a brisk index finger flexion in two groups of subjects: (1) 29 who composed our database from previous experiments and were asked to "go-as-fast-as-possible" (go-fast), but actually performed the movement with different speeds (238-1180°/s), and (2) ten new subjects who performed the go-fast movement at more than 500°/s and were then asked to go-slow at about 50 % of their initial velocity, thus moving at 300-800°/s. No correlation between APA latency and actual movement speed was observed when all subjects had to go-fast (p > 0.50), while delayed APAs were found in the ten new subjects when they had to go-slow (p < 0.001). Moreover, in the speed range between 300 and 800°/s, the APA latency depended only on movement instruction: subjects going fast showed earlier APAs than those going slow (p < 0.001). These data suggest a stronger role of the intended movement velocity versus the actual one in modifying the timing of postural muscles recruitment with respect to the prime mover. These results also strengthen the idea of a shared postural and voluntary command within the same motor act.
APA; speed; motor control; posture; voluntary movement; human
Settore BIO/09 - Fisiologia
8-ott-2014
Article (author)
File in questo prodotto:
File Dimensione Formato  
APAvelocità_Printed.pdf

accesso riservato

Tipologia: Publisher's version/PDF
Dimensione 429.93 kB
Formato Adobe PDF
429.93 kB Adobe PDF   Visualizza/Apri   Richiedi una copia
APA latency mov velocity PostPrint.pdf

accesso aperto

Tipologia: Post-print, accepted manuscript ecc. (versione accettata dall'editore)
Dimensione 424.67 kB
Formato Adobe PDF
424.67 kB Adobe PDF Visualizza/Apri
Pubblicazioni consigliate

Caricamento pubblicazioni consigliate

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/2434/241575
Citazioni
  • ???jsp.display-item.citation.pmc??? 4
  • Scopus 8
  • ???jsp.display-item.citation.isi??? 8
social impact