Effect of a juggling-based physical activity on postural stability, reaction time, and attention focus in older adults: a randomized crossover study

Abstract

Background: In the aging society, more attention is paid to the promotion of forms of physical activity that can improve postural stability and cognitive functioning. In this context, the importance of combined exercises, requiring simultaneous physical and cognitive involvement, is emphasized. Juggling seems to be a form of activity that is both cognitively and physically demanding. The purpose of this study was to determine the effect of additional juggling exercise on postural stability and cognitive abilities in healthy, physically active older adults.

Methods: Twenty-six healthy and physically active older adults (70.08±4.40 years old) were included in a randomized crossover study. The addition of juggling three times a week during four weeks was the main intervention (one period), while the control phase included four weeks with no addition of juggling (second period). Measurements of postural stability and cognitive abilities were performed before and after each period. For the purpose of postural stability assessment, a velocity of center of pressure with root mean square, area 95 percentile, medio-lateral and anterior-posterior range of motion were measured. Center of pressure signals were obtained using an AccuGait™ System force plate in three conditions: free standing, dual-task and limits of stability. The Vienna Test System was used for the assessment of selected cognitive abilities. A battery of reaction time tests and Cognitrone test were used for this purpose.

Results: A significant interaction effect of intervention and time was observed in the postural stability dual-task condition in the root mean square of the center of pressure velocity in the advantage of the juggling period (medio-lateral: F=14.83, p<.01, ƞ_p²=.37; anterior-posterior: F=26.30, p<.01, ƞ_p²=.51). Additionally, moderate effect sizes were observed in the velocity of the center of pressure and variability of simple reaction time measurements, but without statistical significance.

Conclusions: The results of this study indicate that the implementation of juggling activity in everyday life may have positive effects on cognitive abilities and postural stability in healthy, physically active older adults, but the true effect may be low to moderate.

Trial registration: The study was registered retrospectively (30.10.2023) at ClinicalTrials.gov (NCT06108713).

Keywords: Cognitive abilities; Dual-task; Physical activity.

Fig. 1

Study design chart; n – number of participants PRE₁/PRE₂ – before first/second period; POST₁/POST₂ – after first/second period; RT – reaction time tests; COG – attention focus tests; PST – postural stability tests; CHAMPS – physical activity questionnaire

Fig. 2

PRE/POST differences in postural stability tests. PST_C – postural stability tests without additional task; PST_E – postural stability test with additional task (counting); PST_LOS – limits of stability test, Vcop – velocity of center of pressure, RMS_VX – medio-lateral root mean square of velocity; RMS_VY – anterior-posterior root mean square of velocity; Area95 – area 95 percentile, RangeX – medio-lateral range of sway, RangeY – anterior-posterior range of sway, JP – juggling period, NJP – non juggling period

Fig. 3

PRE/POST differences in cognitive function assessment. SRT – simple reaction time, CRT – complex reaction time, MT – motor time, VSRT – variability of simple reaction time, VCRT – variability of complex reaction time, VMT – variability of motor time, COG_CR - average time of correct rejections in the Cognitrone test, COG_AR – average time of correct acceptance in the Cognitrone test, JP – juggling period, NJP – non-juggling period