Determinants of Different Aspects of Upper-Limb Activity after Stroke

Abstract

We examined factors associated with different aspects of upper-limb (UL) activity in chronic stroke to better understand and improve UL activity in daily life. Three different aspects of UL activity were represented by four sensor measures: (1) contribution to activity according to activity ratio and magnitude ratio, (2) intensity of activity according to bilateral magnitude, and (3) variability of activity according to variation ratio. We combined data from a Belgian and Danish patient cohort (n = 126) and developed four models to determine associated factors for each sensor measure. Results from standard multiple regression show that motor impairment (Fugl–Meyer assessment) accounted for the largest part of the explained variance in all sensor measures (18–61%), with less motor impairment resulting in higher UL activity values (p < 0.001). Higher activity ratio, magnitude ratio, and variation ratio were further explained by having the dominant hand affected (p < 0.007). Bilateral magnitude had the lowest explained variance (adjusted R2 = 0.376), and higher values were further associated with being young and female. As motor impairment and biological aspects accounted for only one- to two-thirds of the variance in UL activity, rehabilitation including behavioral strategies might be important to increase the different aspects of UL activity.

External Validation of a Dynamic Prediction Model for Upper Limb Function After Stroke

“…The data set for external validation was obtained from a prospective cohort study where the prediction accuracy of the components of the PREP2 algorithm was assessed when applied 2 weeks after stroke. 11 Based on the same cohort, 3- and 6-month follow-up data were obtained which have been published elsewhere 16 , 17 and were here used for the purpose of external validation.…”

Optimizing Epoch Length and Activity Count Threshold Parameters in Accelerometry: Enhancing Upper Extremity Use Quantification in Cerebral Palsy

“…This variation can have a significant impact on AC , and consequently, on the threshold used for AC . However, this approach has been used in the literature with some variations from one author to another, such as thresholds of ≥2 AC [ 17 , 18 ], ≥1 AC [ 19 , 20 ], or >0 AC [ 21 ] on 1 s epochs, or a ≥1 AC on a 2 s epoch [ 22 , 23 ], without justification for these arbitrary changes. The current threshold of 2 AC has recently been questioned on the grounds that such a low threshold would only discriminate periods of absolute stillness, thus including a large proportion of small non-functional movements, leading to a significant overestimation of functional UE use.…”

“…Likewise, wide variations in epoch length are observed in the literature, with epochs of 1 s [ 17 , 18 , 19 , 20 , 21 ], 2 s [ 16 , 23 ], 15 s [ 25 , 26 ], 60 s [ 27 , 28 ], or 120 s [ 29 ], often without any justification for the choice of epoch. Experts in the field have recommended the use of 1 s epochs [ 15 , 30 ].…”