Age- and low back pain-related differences in trunk muscle activation during a one-legged stance balance task

Publication date: Available online 11 January 2019

Source: Gait & Posture

Author(s): Rubens A. da Silva, Edgar R. Vieira, Guillaume Léonard, Louis-David Beaulieu, Suzy Ngomo, Alexandre H. Nowotny, César F. Amorim

Abstract

Background

Postural control declines with age and can be affected by low back pain. The changes in trunk muscle activation may also help to better explain these negative results on postural control measures.

Aim

The objective of this study was to compare the trunk muscle activity of younger and older subjects, with and without chronic low back pain (CLBP), during a one-legged stance task.

Methods and procedures

Twenty (20) with, and 20 subjects without nonspecific CLBP participated in the study. Each group was comprised of 10 younger (50% males; mean age: 31 years) and 10 older adults (50% males; mean age: 71 years). Subjects performed 3 × 30-second trials of a one-legged stance, with eyes open, on a force platform, while surface electromyography (EMG) measurements were obtained bilaterally on the multifidus at L5, iliocostalis lumborum at L3, rectus abdominis and biceps femoris muscles.

Outcomes and results

EMG amplitude analysis was processed by the Root Mean Square (250 ms window epochs) and normalized by the peak of activation during the balance tasks, to determine the muscular activity of each muscle. Participants with CLBP presented 15% lower lumbar muscle activation (p <  0.05), and 23% higher co-activation (ratio between rectus adominis by multifidus) than participants without CLBP, regardless of age. Significant differences (p <  0.05) between older and young groups were observed only for lower lumbar muscles (mean 24% lower in older than younger adults) and rectus adominis muscles (mean 17% lower in older than younger adults).

Conclusion and implications

CLBP individuals have different trunk muscle activity than those without CLBP, and older adults exhibit lower trunk activation during a one-legged stance balance task. The use of the EMG in evaluation of trunk neuromuscular function during one-legged stance may thus be a valuable tool when assessing balance in CLBP and older people.

from #Audiology via ola Kala on Inoreader http://bit.ly/2VJEr8S