The role of predictability of the magnitude of a perturbation in control of vertical posture when catching an object

• Published in: Human movement science 2021-12, Vol.80, p.102890-102890, Article 102890
• Main Authors: Kaewmanee, Tippawan, Liang, Huaqing, Aruin, Alexander S.
• Format: Article
• Language: English
• Subjects: Catching; Magnitude; Perturbation; Postural adjustments; Predictability
• ISSN: 0167-9457; 1872-7646
• DOI: 10.1016/j.humov.2021.102890

The predictability of perturbation magnitude plays an important role in control of standing posture. The aim of the study was to examine anticipatory (APAs) and compensatory (CPAs) postural adjustments in response to catching objects of uncertain mass. Twenty adults caught the same object with either light or heavy weight placed in it. Electromyographic activity of eight trunk and leg muscles, displacements of the center of pressure, and angular displacement of the shoulder joint were recorded and analyzed during the APAs and CPAs intervals. When the subjects experienced repeated catching of the object with the same weight, they estimated the object mass beforehand and generated APAs more precisely. When the object mass changed unpredictably, they generated APAs based on the most recent catch and needed four to six trials to optimize APAs and CPAs. The muscle co-contraction was a primary pattern for catching the object of uncertain mass. The results of the study suggest that catching the object of uncertain mass is a challenging task that involves co-contraction of postural muscles to maintain balance. •We studied the effect of the predictability of perturbations in control of standing posture.•Co-contraction of muscles is used while catching objects.•Four to six repetitions are needed to optimize postural control when catching object of uncertain mass.