Affiliations: [a] Department of Physical Therapy and Occupational Therapy, São Paulo State University, Marília, Brazil | [b] Department of Physical Therapy, Uberlandia Federal University, Uberlandia, Brazil | [c] Department of Physical Education, São Paulo State University, Rio Claro, Brazil | [d] Department of Physical Therapy, São Paulo State University, Presidente Prudente, Brazil
Correspondence:
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Corresponding author: Nise Ribeiro Marques, Departamento de Fisioterapia e Terapia Ocupacional, Universidade Estadual Paulista, Avenida Hygino Muzzi Filho, 737, Mirante, CEP 13525-000, Marília, SP, Brazil. E-mail:nisermarques@yahoo.com.br
Abstract: BACKGROUND: Walking is a complex motor task that requires an integrated coordination of
the trunk, lower limb, and upper limb movements. Previously, few studies
have investigated the activation pattern of trunk muscles during walking.
However, the mechanisms by how aging affects the recruitment of trunk
muscles during walking remain unclear. OBJECTIVE: The present study aimed to compare the activation of trunk and lower limb
muscles during walking in younger and older women. METHODS: Fifteen younger women between 18 and 30 yr and 19 older women between 60-82 yr walked on the treadmill at a self-selected speed, while 1-min surface
electromyography (EMG) signals were recorded from the multifidus, internal
oblique, gluteus maximus, rectus femoris, biceps femoris, tibialis anterior,
and gastrocnemius lateralis. EMG signals were processed and a linear
envelope was calculated at an initial stance (50 ms after heel contact) and
final stance (50 ms before toe-off). RESULTS: Compared with younger women, older women had 52.32% lower activation of
the internal oblique (p = 0.027) and 39.95% lower activation of the rectus
femoris (p = 0.003) at initial stance. CONCLUSION: Results of this study demonstrated that older women had lower activation of
trunk and knee muscles during the initial stance, which may have resulted
from weakness and balance impairments caused by aging.
