Tohoku J. Exp. Med., 2018 June, 245(2)

Decreased Respiratory Muscle Function Is Associated with Impaired Trunk Balance among Chronic Stroke Patients: A Cross-sectional Study

KYEONGBONG LEE,¹ JI-EUN CHO,² DAL-YEON HWANG³ and WANHEE LEE⁴

¹Physical Therapy Part, Department of Physical and Rehabilitation Medicine, Samsung Medical Center, Seoul, Korea
²Department of Physical Therapy, Graduate School of Sahmyook University, Seoul, Korea
³Department of Physical Therapy, Myongji Choonhye Rehabilitation Hospital, Seoul, Korea
⁴Department of Physical Therapy, College of Health Science, Sahmyook University, Seoul, Korea

The abdominal muscles play a role in trunk balance. Abdominal muscle thickness is asymmetrical in stroke survivors, who also have decreased respiratory muscle function. We compared the thickness of the abdominal muscles between the affected and less affected sides in stroke survivors. In addition, the relationship between respiratory muscle function and trunk balance was evaluated. Chronic stroke patients (18 men, 15 women; mean age, 58.94 ± 12.30 years; Mini-Mental Status Examination score ≥ 24) who could sit without assist were enrolled. Abdominal muscle thickness during rest and contraction was measured with ultrasonography, and the thickening ratio was calculated. Respiratory muscle function assessment included maximum respiratory pressure, peak flow, and air volume. Trunk function was evaluated using the Trunk Impairment Scale, and trunk balance was estimated based on the center of pressure velocity and path length within the limit of stability in sitting posture. Abdominal muscles were significantly thinner on the affected side, and the thickening ratio was lower in the affected side (P < 0.05). In addition, the higher thickening ratio of the affected side showed significant relationship with higher trunk function. Moreover, higher respiratory muscle function was significantly correlated with higher level of trunk function and balance in stroke patients (P < 0.05). Thus, chronic stroke survivors have decreased abdominal muscle thickness on the affected side, and respiratory muscle function has positive correlation with trunk function and balance. We propose that respiratory muscle training should be included as part of trunk balance training in chronic stroke patients.

keywords —— forced expiration; inspiration; respiratory muscle function; stroke; trunk balance.

© 2018 Tohoku University Medical Press

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Tohoku J. Exp. Med., 2018, 245, 79-88

Correspondence: WanHee Lee, P.T., Ph.D., Department of Physical Therapy, College of Health Science, Sahmyook University, 26-12 Kongnung 2-dong, Hwrangro-815, Nowon-gu, Seoul 01795, Republic of Korea.

e-mail: whlee@syu.ac.kr