Background and objective: Impaired trunk control and core muscle weakness affect balance capacity after stroke, but confirmatory literature is lacking. The objective was to examine the relationship between trunk control, core muscle strength and self-confidence on balance efficacy in community-dwelling chronic stroke survivors and to identify trunk performance measures for determining balance confidence.
Methods: Patients with a median post-stroke duration of 12 (IQR 7-18) months and independent walking ability participated in this cross-sectional study. Trunk control, core muscle strength and balance confidence were measured using trunk impairment scale 2.0 (TIS 2.0), handheld dynamometer and activity-specific balance confidence scale, respectively. Correlation among TIS 2.0, core muscle strength and balance confidence were tested by Pearson's correlation coefficient. Stepwise multivariate linear regression analysis was conducted to examine the most important trunk performance variables determining balance confidence.
Results: Of 177 study participants, the median (IQR) score for TIS 2.0 was 10 (7-12) out of 16 and for balance confidence 41 (27-61) out of 100. Trunk control was highly correlated to overall core muscles strength (r = 0.61-0.70, p <.001) and balance confidence (r = 0.66, p <.001). The major trunk determinants of balance confidence were TIS 2.0 total score (partial R2 = 0.433) and dynamic sitting balance, i.e. trunk lateral flexion (partial R2 = 0.376) in chronic stroke.
Conclusion: A significant and strong positive association exists among trunk control, core muscles strength and balance confidence in community-dwelling patients with chronic stroke, warranting further investigation of the effect of targeted trunk rehabilitation strategies on functional balance.
Keywords: Trunk control; balance confidence; core strength; stroke.