Evidence of interventions to increase muscle strength and improve gait after stroke

Abstract

The overall purpose of this thesis was to provide clinical evidence, based on high quality research, regarding effects of interventions aimed at increasing muscle strength and improving gait after stroke. The definition of each study which comprised the thesis and its research design began by carefully reading the Clinical Guidelines for Stroke Management – a clinical guideline developed with the purpose of making clinical recommendations for prevention and treatment of patients after stroke. The rehabilitation chapter of the guideline was analyzed in order to understand the current level of evidence, to identify areas with lack of evidence, and to develop studies capable of providing evidence that could help clinical practice regarding muscle weakness and walking limitations after stroke. Four studies were planned: three systematic reviews and one experimental trial. The first study examined the effect of cyclical electrical stimulation on muscle strength and activities after stroke. The research questions were: Does electrical stimulation increase strength after stroke? Are any benefits maintained beyond the intervention period or carried over to activity? A systematic review with meta-analysis of randomised or controlled trials was conducted. Participants were adults who have had a stroke, and the intervention was cyclical electrical stimulation applied in order to increase muscle strength. The outcome measures were related to muscle strength and to activity. Sixteen trials, representing 17 relevant comparisons, were included in this systematic review. Effect sizes were calculated as standardised mean differences. Overall, electrical stimulation increased strength by a standardised mean difference (SMD) of 0.47 (95% CI 0.26 to 0.68) and this effect was maintained beyond the intervention period (SMD 0.33, 95% CI 0.07 to 0.60). Electrical stimulation also improved activity (SMD 0.30, 95% CI 0.05 to 0.56) and this effect was also maintained beyond the intervention period (SMD 0.38, 95% CI 0.09 to 0.66). The second study examined the effect of the addition of cueing of cadence to walking training for improving walking speed, stride length, cadence and symmetry after stroke. The research question was: After stroke, is walking training with cueing of cadence superior to walking training alone in improving walking speed, stride length, cadence and symmetry? A systematic review with meta-analysis of randomised or controlled trials was conducted. Participants were ambulatory adults who have had a stroke. The intervention was walking training with cueing of cadence, and four walking outcomes were of interest: walking speed, stride length, cadence and symmetry. This review included seven trials involving 211 participants. Because one trial caused substantial statistical heterogeneity, meta-analyses were conducted with and without this trial. Walking training with cueing of cadence improved walking speed by 0.23 m/s (95% CI 0.18 to 0.27, I2 = 0%), stride length by 0.21 m (95% CI 0.14 to 0.28, I2 = 18%), cadence by 19 steps/minute (95% CI 14 to 23, I2 = 40%), and symmetry by 15% (95% CI 3 to 26, random effects) more than walking training alone. The third study examined the effect of the addition of virtual reality-based training to walking training for improving walking speed after stroke. The research questions were: (i) Is walking training associated with virtual reality-based training effective in increasing walking speed after stroke? (ii) Is this type of intervention more effective in increasing walking speed, than non-virtual reality-based walking interventions? A systematic review with meta-analysis of randomised clinical trials was conducted. Participants were adults with chronic stroke and the experimental intervention was walking training associated with virtual reality-based training to increase walking speed. The outcome data regarding walking speed were extracted from the eligible trials and were combined using a meta-analysis approach. Seven trials, representing eight comparisons, were included in this systematic review. Overall, the virtual reality-based training increased walking speed by 0.17 m/s (IC 95% 0.08 to 0.26), compared with placebo/nothing or non-walking interventions. In addition, the virtual reality-based training increased walking speed by 0.15 m/s (IC 95% 0.05 to 0.24), compared with non-virtual reality walking interventions. The fourth study examined the effect of the provision of a cane to ambulatory people after stroke on walking speed, step length, and cadence. The research questions were: (i) What is the effect of the provision of a cane on speed, step length, and cadence in people with chronic stroke who are independently ambulatory? (ii) Is there a differential effect according to comfortable walking speed (<0.4 versus 0.4-0.8 versus >0.8 m/s)? Twenty-four people with chronic stroke, who were not regular users of walking sticks, were evaluated under two different experimental conditions: walking with and without a cane. Walking was reported as speed (m/s), step length (m), and cadence (steps/min). Participants were categorized as slow (<0.4 m/s), intermediate (0.4-0.8 m/s), and fast walkers (>0.8 m/s). The provision of a cane to the intermediate walkers produced a 0.27 m/s (95% CI 0.18 to 0.36) increase in speed compared with the fast walkers, and a 0.12 m/s (95% CI 0.03 to 0.21) increase compared with the slow walkers. It also produced 0.05 m (95% CI 0.02 to 0.08) increase in step length and 20 steps/min (95% CI 12 to 28) increase in cadence compared with the fast walkers. The provision of a cane produced the most benefit in intermediate walkers, and was detrimental to the fast walkers. Canes can be prescribed to stroke survivors with moderate and severe walking limitations, but caution should be taken regarding their prescription for fast walkers.