Ambulation recovery after stroke

Abstract

Most stroke survivors regard successful independent ambulation important. However, ambulation recovery is limited following stroke. Historically, limited availability of objective tools and measures to characterise free-living ambulation recovery has restricted investigation of this outcome after survivors return home. However, commercially available devices, including accelerometers and portable global positioning systems, are now available. Thus, this thesis aimed to characterise free-living ambulation recovery over the first six months after stroke survivors returned home from hospital and determine what factors at discharge contributed to ambulation recovery across this time.The first study of this thesis investigated the concurrent validity and retest reliability of accelerometers (ActivPAL TM and Sensewear Pro 2 Armband) and global positioning systems (GPS) (Garmin forerunner 405CX) to measure free-living ambulation after stroke. Measures of step counts, time spent walking, energy expenditure, distance and location were taken during walking tasks that impose demands similar to those encountered when walking in the community as well as free-living community ambulation over four days. This study determined that the ActivPAL TM was valid and reliable for measuring ambulation after stroke. The GPS was valid and reliable for all measures except distance, whereas the Sensewear Pro 2 Armband recorded with high error during all walking tests.The second study aimed to characterise ambulation activity after stroke across the first six months following discharge from hospital and investigate how ambulation activity changed across this time period. Free-living ambulation activity was measured over four days using the ActivPAL TM accelerometer at one, three and six months after stroke survivors left hospital. Measures of volume (daily step counts and time spent walking, sitting/lying, standing and upright), frequency (total number of ambulation bouts; number of bouts and total time spent in short, medium and long duration ambulation bouts) and intensity (number of bouts and total time per day spent in low, moderate and high intensity ambulation bouts) of ambulation activity were collected. This study highlighted that volume of ambulation activity was low across the first six months following hospital discharge, with a majority of ambulation bouts short and low in intensity. Stroke survivors rarely engaged in long duration and high intensity ambulation bouts across the first six months.Daily volume of ambulation activity increased from one month to both three and six months after iv discharge from hospital through an increase in medium duration and moderate intensity ambulation only.The third study aimed to determine what factors at discharge were related to and predicted ambulation activity outcomes over the first six months following hospital discharge in stroke.Factors including age, fatigue, mood, executive function, gait speed, gait endurance, perceived stroke recovery, pre-stroke physical activity, ambulat...

Carbonyldiimidazole‐accelerated efficient cure of epoxidized soybean oil with dicyandiamide

“…[1][2][3][4][11][12][13] The curing strategy of EVO through both step-growth polymerization and chain-growth polymerization (i.e., ring-opening polymerization) has been widely studied. For example, various anhydrides, [14][15][16][17][18][19][20][21][22] acids, 23 amines, [24][25][26] pyridine derivatives, 27 and phenols 28 were used to cross-link the epoxy groups contained in EVO chains, and several photo-initiators 29 and cationic polymerization initiators [30][31][32] were reported as a successful initiator for chaingrowth polymerizations. However, in contrast with the termi-nal epoxy groups (glycidyl), the internal epoxy groups of EVO hardly accept nucleophilic attacks, resulting in poor reactivity for curing.…”