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Asai H1, Endo S2, Inaoka PT1, Nakaizumi D3
1Kanazawa University, Physical Therapy, Kanazawa, Japan, 2Kanazawa Disabled Children's Hospital, Kanazawa, Japan, 3Kanazawa Red Cross Hospital, Kanazawa, Japan
Background: The perception of trunk position plays an important role in sitting posture control. A proper sitting posture control is necessary to prevent backward falling especially in those with low sitting stability. We hypothesized that adding pressure sensory information on the coccygeal skin may help the backward leaning perception during sitting.
Purpose: The purpose of this study was to investigate the effects of an additional pressure stimulus on coccygeal skin on the perceptibility of the sitting backward leaning in patients with stroke.
Methods: Thirteen chronic stroke patients (64.8±10.4 years) and twelve age matched healthy subjects (63.8±10.8 years) volunteered for this study.
All measurements were taken with the participants seated on a height adjustable chair. A goniometer with a resolution of 0.1° was used to measure the trunk angle (the angle from the right acromion process to the right great trochanter and the vertical line). A half-cylindrically shaped original tool made of plastic eraser was designed to add pressure stimulation to the coccygeal skin while leaning backwardly on sitting position. The reference angles were set as follows: 1) the trunk angle where the participants felt the highest pressure stimulation to the coccygeal skin while leaning from quiet sitting position (x°), 2) x° + 5° forwardly (+ 5°), 3) x° + 10° forwardly (+ 10°). This experiment was conducted under both the stimulated condition (pressure with the original tool) and the normal condition. Three random reference angles were repeated 5 times. The perceptibility of three reference angles was evaluated by the absolute error between the reference angle and the reproduced angle. The effect of the condition on the absolute errors for each participants group and the relationship between the absolute error under the normal condition and the pressure effect index (ratio of the absolute error under the pressure condition to that under the normal condition) were calculated. A two-way repeated-measures analysis of variance was used to study the effect of the reference position and condition on the absolute errors for each participants group. For the x angle, Pearson's correlation coefficient was used to study the relationship between the absolute error under the normal condition and the pressure effect index (ratio of the absolute error under the stimulated condition to the normal condition).
Results: In the x angle, there was a main effect of the condition on the absolute error in the control group (the stimulated condition the normal condition) (p 0.01), but not in the patients group. In the patients group, the relationship between the absolute error under the normal condition and the pressure effect index in the x angle showed a significant negative correlation (p 0.001).
Conclusion(s): An effect of the additional coccygeal skin pressure on the perceptibility of the backward sitting position was detected in the control subjects and the stroke patients with low perceptibility of the backward-leaning position.
Implications: Increasing pressure sensation from the coccygeal skin may be effective to improve stability in backward-leaning sitting position on the stroke patients with low sitting stability.
Keywords: Perception, sitting backward-leaning, stroke
Funding acknowledgements: This work was supported bt JSPS KAKENHI, Grant-in-Aid for Science Research (C), Grant Number 26350609.
Purpose: The purpose of this study was to investigate the effects of an additional pressure stimulus on coccygeal skin on the perceptibility of the sitting backward leaning in patients with stroke.
Methods: Thirteen chronic stroke patients (64.8±10.4 years) and twelve age matched healthy subjects (63.8±10.8 years) volunteered for this study.
All measurements were taken with the participants seated on a height adjustable chair. A goniometer with a resolution of 0.1° was used to measure the trunk angle (the angle from the right acromion process to the right great trochanter and the vertical line). A half-cylindrically shaped original tool made of plastic eraser was designed to add pressure stimulation to the coccygeal skin while leaning backwardly on sitting position. The reference angles were set as follows: 1) the trunk angle where the participants felt the highest pressure stimulation to the coccygeal skin while leaning from quiet sitting position (x°), 2) x° + 5° forwardly (+ 5°), 3) x° + 10° forwardly (+ 10°). This experiment was conducted under both the stimulated condition (pressure with the original tool) and the normal condition. Three random reference angles were repeated 5 times. The perceptibility of three reference angles was evaluated by the absolute error between the reference angle and the reproduced angle. The effect of the condition on the absolute errors for each participants group and the relationship between the absolute error under the normal condition and the pressure effect index (ratio of the absolute error under the pressure condition to that under the normal condition) were calculated. A two-way repeated-measures analysis of variance was used to study the effect of the reference position and condition on the absolute errors for each participants group. For the x angle, Pearson's correlation coefficient was used to study the relationship between the absolute error under the normal condition and the pressure effect index (ratio of the absolute error under the stimulated condition to the normal condition).
Results: In the x angle, there was a main effect of the condition on the absolute error in the control group (the stimulated condition the normal condition) (p 0.01), but not in the patients group. In the patients group, the relationship between the absolute error under the normal condition and the pressure effect index in the x angle showed a significant negative correlation (p 0.001).
Conclusion(s): An effect of the additional coccygeal skin pressure on the perceptibility of the backward sitting position was detected in the control subjects and the stroke patients with low perceptibility of the backward-leaning position.
Implications: Increasing pressure sensation from the coccygeal skin may be effective to improve stability in backward-leaning sitting position on the stroke patients with low sitting stability.
Keywords: Perception, sitting backward-leaning, stroke
Funding acknowledgements: This work was supported bt JSPS KAKENHI, Grant-in-Aid for Science Research (C), Grant Number 26350609.
Topic: Neurology: stroke; Human movement analysis; Older people
Ethics approval required: Yes
Institution: Kanazawa University
Ethics committee: Institutional ethics committee of Kanazawa University
Ethics number: 815-1, 815-2
All authors, affiliations and abstracts have been published as submitted.
