Multi-Joint Synergy in Foot Height Stabilization Across Different Running Speeds: An Uncontrolled Manifold Analysis

Autor(es)

Dias, Mateus S. ; Freitas, Sandra M. S. F. ; de Freitas, Paulo B.

• Tipo de documento: Artigo Científico
• Fonte: RESEARCH QUARTERLY FOR EXERCISE AND SPORT; v. N/A, p. 10-pg., 2025-04-12.

Resumo

The uncontrolled manifold (UCM) framework was employed to investigate the presence of a multi-joint synergy stabilizing foot height during the swing phase of treadmill running and its potential dependence on running speed. Experienced runners (N = 28; aged 22-51) ran on an instrumented treadmill set at three different speeds: 2.5, 3.5, and 4.5 m/s. Kinematic data were utilized to calculate UCM outcomes: variances in the joint space that had no effect (VUCM) and those that influenced (VORT) foot height, and the synergy index (Delta VZ, the normalized difference between VUCM and VORT). They were computed for each normalized frame (1-100%) of the swing phase and averaged in 10% intervals. Delta VZ was greater than zero and varied across the swing phase, being lowest at 51-60% and highest at 81-100%. Delta VZ was the lowest at the slowest speed in the second half of the swing phase, because of a low VUCM. The findings indicate that the CNS organizes a multi-joint synergy to stabilize foot height, with the strongest synergy at the end of the swing phase to ensure safe foot placement and landing. Faster running speeds enhance this synergy, allowing greater adaptability to perturbations, while slower speeds lead to a more cautious approach, reducing overall variance. (AU)

• Processo FAPESP: 20/11317-9 - Controle sinergético da estabilidade da altura mínima pé-solo durante a fase de balanço do andar: análise pela abordagem da variância não controlada
• Beneficiário: Paulo Barbosa de Freitas Júnior
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 21/10105-0 - Controle sinergético do deslocamento vertical do pé durante a fase de balanço na corrida: análise pela abordagem da variância não controlada
• Beneficiário: Mateus Santos Dias
• Modalidade de apoio: Bolsas no Brasil - Iniciação Científica