Author(s): WISSMANN, A., HILL, M., MUEHLBAUER, T., LAMBRICH, J., Institution: UNIVERSITY OF DUISBURG-ESSEN, Country: GERMANY, Abstract-ID: 337

INTRODUCTION:
Previous research has shown that, compared to young adults, children did not adopt a postural “stiffening” response when confronted with a height-induced threat during quite bipedal standing [1, 2, 3]. However, it remains unclear whether this maladaptive behaviour is also evident in a more difficult (semi-static) balance task and how this is influenced by the different arm movement strategies. The objective of this study was to compare the effects of arm movement strategies on balance and emotional state outcomes during a semi-static task performed on ground level and at height in children versus young adults.
METHODS:
Children (n=25, age: 11.7 ± 0.5 years) and young adults (n=23, age: 21.8 ± 3.4 years) executed a continuous contralateral leg swing for 30 s during unipedal stance at both ground-level (no threat) and 80 cm above ground (threat). In both conditions, the task was performed with free and restricted arm movements. Subjective balance-related indicators—including fear of falling, perceived instability, and conscious balance processing—were assessed using self-report questionnaires. Objective balance-related parameters comprised sway amplitude and frequency. Statistical analyses were conducted using 2 (Group) × 2 (Threat) × 2 (Arm) ANOVAs (ηp²).
RESULTS:
Compared with young adults, children demonstrated significantly greater threat-related changes in both emotional state and balance outcomes. When standing above ground (threat), children exhibited more pronounced emotional and cognitive responses (Group × Threat: fear of falling, p = .033, ηp² = .10; perceived instability, p = .006, ηp² = .15; conscious balance processing, p = .039, ηp² = .09) as well as greater sway frequency, particularly during the restricted arm movement condition (Group × Threat × Arm: AP COP MPF, p = .032, ηp² = .10).
CONCLUSION:
The observation of an increased postural “stiffening” response (i.e., greater sway frequency) when standing at height with restricted arms in children contrasts with previous research [3] and requires further studies.

References:
1. A.L. Adkin, M.G. Carpenter, New Insights on Emotional Contributions to Human Postural Control, Front. Neurol. 9 (2018) 789.
2. A.M. Wissmann, M. Hill, T. Muehlbauer, J. Lambrich, Arm movement strategies did not influence emotional state and static postural control during height-induced postural threat in children and young adults, Front. Hum. Neurosci. 19 (2025) 1635330.
3. M. Hill, L. Brayne, E. Hosseini, M. Duncan, T. Muehlbauer, S.R. Lord, T.J. Ellmers, The influence of fear of falling on the control of upright stance across the lifespan, Gait & Posture 109 (2024) 226–232.