Electromyography of symmetrical trunk movements and trunk position sense in chronic stroke patients

Abstract

[Purpose] To explore the differences in bilateral trunk muscle activation between chronic stroke patients and healthy controls, this study investigated the symmetry index and cross-correlation of trunk muscles during trunk flexion and extension movements. This study also assessed the differences in trunk reposition error between groups and the association between trunk reposition error and bilateral trunk muscle activation. [Subjects and Methods] Fifteen stroke patients and 15 age- and gender-matched healthy subjects participated. Bilateral trunk muscle activations were collected by electromyography during trunk flexion and extension. Trunk reposition errors in trunk flexion and extension directions were recorded by a Qualisys motion capture system. [Results] Compared with the healthy controls, the stroke patients presented lower symmetrical muscle activation of the bilateral internal oblique and lower cross-correlation of abdominal muscles during trunk flexion, and lower symmetry index and cross-correlation of erector spinae in trunk extension. They also showed a larger trunk extension reposition error. A smaller trunk reposition error was associated with higher cross-correlation of bilateral trunk muscles during trunk movements in all subjects. [Conclusion] Trunk muscle function during symmetrical trunk movements and trunk reposition sense were impaired in the chronic stroke patients, and trunk position sense was associated with trunk muscle functions. Future studies should pay attention to symmetrical trunk movements as well as trunk extension position sense for patients with chronic stroke.

Anteroposterior perception of the trunk position while seated without the feet touching the floor

“…In this study, the perception of seven positions of the trunk in the anteroposterior direction while sitting was investigated. Almost all previous studies have adopted only one or two target positions and a starting position to investigate the trunk position perception 9 , 10 , 11 , 12 ) . However, our study adopted a method in which participants were instructed to stand up right after referencing the target position instead of returning to the starting position.…”

“…The measurement of the accuracy of the perception during various trunk positions while seated is necessary to investigate the anticipatory postural control in accordance with various sitting positions. It has been shown that the perception of the trunk position in stroke patients is lower than that in normal subjects based on the reproducibility of the trunk position in a sitting posture 9 , 10 ) . The reproducibility of the lumbar position in low back pain patients has also been investigated 11 , 12 ) .…”

Perception of trunk inclination during sitting with feet in contact with the floor

“…Therefore, it is important to perceive one’s own body position accurately. Several reports have examined the perception of the trunk position while sitting, including the subjective postural vertical (SPV)4,5,6 ) and trunk position perception7, 8 ) . The SPV is the perception of body verticality4,5,6 ) , in which somatosensory information has been suggested to have an important role.…”

“…The SPV is the perception of body verticality4,5,6 ) , in which somatosensory information has been suggested to have an important role. The trunk position perception, also known as the “trunk position sense”, has been assessed in studies based on the accuracy of the perceived trunk position on the sagittal plane7, 8 ) . Trunk repositioning error has been used to evaluate the trunk position sense7, 8 ) .…”

“…The trunk position perception, also known as the “trunk position sense”, has been assessed in studies based on the accuracy of the perceived trunk position on the sagittal plane7, 8 ) . Trunk repositioning error has been used to evaluate the trunk position sense7, 8 ) . The trunk position sense was evaluated by the magnitude of the absolute error between the target position and the reproduced position.…”