Background
To date, many wrist actimetric variables dedicated to measuring the upper limbs (UL) in post-stroke patients have been developed but very few comparisons have been made between them. The objective of this study was to compare different actimetric variables of the ULs between a stroke and healthy population.
Methods
Accelerometers were worn continuously for a period of 7 days on both wrists of 19 post-stroke hemiparetic patients as well as 11 healthy subjects. Various wrist actimetry variables were calculated, including the Jerk ratio 50 (JR50, cumulative probability that the Jerk Ratio is between 1 and 2), absolute (FU30) and relative (FUR30) amounts of functional use of movements of the ULs with angular amplitude greater than 30°, and absolute (UH) and relative (UHR) use hours.
Results
FU30, FUR30, UH, UHR and JR50 of the paretic UL of stroke patients were significantly lower than in the non-dominant UL of healthy subjects. For stroke patients, FUR30 was significantly lower than UHR and JR50, suggesting a more clinically sensitive variable to monitor. In an exploratory analysis, FUR tends to decrease with angular range of motion for stroke patients while it remains stable and close to 1 for healthy subjects. UHR, FUR30 and JR50 show linear correlation with Fugl-Meyer score (FM), with r² equal to 0.53, 0.35 and 0.21 respectively.
Conclusion
This study determined that the FUR30 variable provides the most sensitive clinical biomarker of paretic UL use, and that FUR - angular range of motion relationship allows the identification of the UL behaviour of each patient. This ecological information on the level of functional use of the paretic UL can be used to improve follow-up and develop patient-specific therapy.