Segmental phase angles as predictors of functional recovery and activities of daily living in patients after stroke.

Background: This study investigated the association between segmental phase angles and functional outcomes in patients after stroke, hypothesizing that increased segmental phase angle correlates with improved functional status.

Methods: A retrospective cohort study of 1012 patients after stroke was conducted. Whole body and segmental phase angles were measured using bioelectrical impedance analysis within 3 days of admission. Our exposure of interest was segmental phase angle measured via a multifrequency bioelectrical impedance analyzer and calculated as phase angle = arctangent (Xc/R) × (180/π), where R is the resistance of the right half of the body and Xc is the reactance measured at 50 kHz. The primary outcomes were the motor subscale of the functional independence measure (FIM) at discharge and FIM change between admission and discharge. Secondary outcomes included FIM scores for specific activities. Multiple linear regression analysis was performed to assess associations.

Results: Phase angles of the healthy upper and lower limbs demonstrated stronger associations with discharge FIM motor scores (β = 0.175 and β = 0.105, respectively) and FIM motor gain (β = 0.242 and β = 0.092, respectively) compared with whole body or paretic limb phase angles. Upper limb phase angles were more closely related to grooming and toileting abilities, whereas lower limb phase angles were associated with both toileting and locomotion at discharge.

Conclusion: Segmental phase angles, particularly those of the nonparetic limbs, are promising predictors of functional outcomes in patients after stroke. Assessing segmental phase angles may guide targeted interventions and rehabilitation strategies for improving specific activities of daily living.