Individuals post stroke often rely more on hip flexors for limb advancement during walking due to distal weakness but the effects of muscle fatigue in this group is not known. The purpose of this study was to quantify how stroke affects the influence of hip flexor fatigue on over ground walking kinematics and performance and muscle activation. Ten individuals with chronic stroke and 10 without stroke (controls) participated in the study. Maximal walking speed, walking distance, muscle electromyograms (EMG), and lower extremity joint kinematics were compared before and after dynamic, submaximal fatiguing contractions of the hip flexors (30% maximal load) performed until failure of the task. Task duration and decline in hip flexion maximal voluntary contraction (MVC) and power were used to assess fatigue. The stroke and control groups had similar task durations and percent reductions in MVC force following fatiguing contractions. Compared with controls, individuals with stroke had larger percent reductions in maximal walking speed, greater decrements in hip range of motion and peak velocity during swing, greater decrements in ankle velocity and lack of modulation of hip flexor EMG following fatiguing dynamic hip flexion contractions. For a given level of fatigue, the impact on walking function was more profound in individuals with stroke than neurologically intact individuals, and a decreased ability to up regulate hip flexor muscle activity may contribute. These data highlight the importance of monitoring the effect of hip flexor muscle activity during exercise or performance of activities of daily living on walking function post stroke.
Introduction We quantified sub-maximal torque regulation during low to moderate intensity isometric hip flexion contractions in individuals with stroke and the associations with leg function. Methods 10 participants with chronic stroke and 10 controls performed isometric hip flexion contractions at 5%, 10%, 15%, 20%, and 40% of maximal voluntary contraction (MVC) in paretic, non-paretic, and control legs. Results Participants with stroke had larger torque fluctuations (coefficient of variation, CV), for both the paretic and non-paretic legs, than controls (P<0.05) with the largest CV at 5% MVC in the paretic leg (P<0.05). The paretic CV correlated with walking speed (r2 =0.45) and Berg Balance Score (r2=0.38). At 5% MVC, there were larger torque fluctuations in the contralateral leg during paretic contractions compared with the control leg. Conclusions Impaired low-force regulation of paretic leg hip flexion can be functionally relevant and related to control versus strength deficits post stroke.
Introduction Stroke-related changes in maximal dynamic hip flexor muscle fatigability may be more relevant functionally than isometric hip flexor fatigability. Methods Ten subjects with chronic stroke performed 5 sets of 30 hip flexion maximal dynamic voluntary contractions (MDVC). A maximal isometric voluntary contraction (MIVC) was performed before and after completion of the dynamic contractions. Both the paretic and non-paretic legs were tested. Results Reduction in hip flexion MDVC torque in the paretic leg (44.7%) was larger than the non-paretic leg (31.7%). The paretic leg had a larger reduction in rectus femoris EMG (28.9%) between the first and last set of MDVCs than the non-paretic leg (7.4%). Reduction in paretic leg MDVC torque was correlated with self-selected walking speed (r2=0.43), while reductions in MIVC torque were not (r2=0.11). Discussion Reductions in maximal dynamic torque of paretic hip flexors may be a better predictor of walking function than for maximal isometric contractions.
Twenty-six children suffering from juvenile chronic arthritis were entered into a 6-month open evaluation of naproxen suspension. Sixteen patients completed 6-months' treatment, 6 were lost to follow-up and 4 dropped out, 2 because of side-effects (rash, and burning on swallowing the formulation), 1 for lack of efficacy and 1 because of no further need of treatment. Pain severity scores were significantly reduced from admission levels at all monthly follow-up visits and significant overall improvement since the last visit was noted up to third month of treatment, as assessed by doctor and parent/patient. Transient indigestion was reported by 2 patients. No clinically significant trends were noted in any of the laboratory investigations carried out. The results add to the accumulation of data on the use of naproxen in children and underline its long-term efficacy and tolerance.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.