Acute Effects of Assisted Cycling Therapy on Post-Stroke Motor Function: A Pilot Study.

BACKGROUND: Stroke is the most common cause of long-term disability in the United States (US). Assisted Cycling Therapy (ACT) at cadences of about 80 rpm has been associated with improvements in motor and clinical function in other clinical populations. The acute effects of ACT on motor function of persons with stroke have not been investigated. OBJECTIVES: The primary purpose of this cross-over trial was to compare the effects of ACT, voluntary cycling (VC), and no cycling (NC) on upper (Box and Blocks Test) and lower extremity motor function (Lower Extremity Motor Coordination Test) in adults with chronic stroke (age: 60 ± 16 years; months since stroke: 96 ± 85). The secondary purpose was to examine average cycling cadence and ratings of perceived exertion as predictors of change in motor function following the exercise session. METHODS: Twenty-two participants (female = 6, male = 16) completed one 20-min session each of ACT (mean cadence = 79.5 rpm, VC (mean cadence = 51.5 rpm), and NC on separate days in quasi-counterbalanced fashion). RESULTS: Main effects of intervention did not differ between ACT and VC. Within-intervention analyses revealed significant (p < 0.05) pre- to posttest changes in all outcome measures for ACT but only in the Lower Extremity Motor Coordination Test on the non-paretic side for VC. Trend analyses revealed a positive relationship between average ACT cadences and improvements in upper and lower extremity motor function (p < 0.05). A positive relationship between average VC cadences and lower extremity function was also revealed (p < 0.05). CONCLUSION: ACT and VC produced similar acute improvements in paretic and non-paretic lower extremity motor function whereas changes in upper extremity motor function were more limited. Faster cycling cadences seem to be associated with greater acute effects.

Step count accuracy and reliability of two activity tracking devices in people after stroke.

BACKGROUND/PURPOSE: The increasing popularity of activity tracking devices presents an opportunity to monitor physical activity in patients after stroke. We sought to determine the reliability and accuracy of the Garmin Vivofit and Fitbit Zip for adults after stroke. METHODS: Twenty-four participants with stroke-induced hemiparesis wore a Fitbit Zip on the nonparetic hip and Garmin Vivofits on both wrists during a 6-minute walk test to determine the accuracy of the devices against video-determined step counts. Participants also wore the devices during two trials of exactly 50 steps to determine the reliability of the devices. RESULTS: Fitbit Zip showed excellent reliability (ICC2,1 = 0.974) and accuracy (4.2% error) for participants who walked faster than 0.35 m/s. Garmin Vivofit (nonparetic side) had excellent reliability (ICC2,1 = 0.964) but poor accuracy (≤-16.0%) for all participants. Garmin Vivofit (paretic side) had excellent reliability (ICC2,1 = 0.858) and accuracy (-4.0% error) for faster walkers (>0.48 m/s) but poor accuracy (-68.2%) for slower walkers. CONCLUSION: Fitbit Zip was more accurate and reliable for persons with stroke than Garmin Vivofit, but slower walking speeds were associated with greater undercounting of steps for both devices. The Fitbit Zip is appropriate for counting steps in adults poststroke who range from household to community ambulators.

Improvements in manual dexterity relate to improvements in cognitive planning after assisted cycling therapy (ACT) in adolescents with down syndrome.

We have previously reported beneficial effects of acute (i.e., single session) Assisted Cycling Therapy (ACT) on manual dexterity and cognitive planning ability in adolescents with Down syndrome (DS). In the present study, we report the chronic effects of eight weeks of ACT, voluntary cycling (VC), and no cycling (NC), on the same measures in adolescents with DS. Participants completed 8 weeks of ACT, VC, or NC. Those in the ACT and VC groups completed 30min sessions three times per week on a stationary bicycle. During ACT, the mechanical motor of the bicycle augmented the cadence to a rate which was on average 79% faster than the voluntary cadence. During VC, the participants pedaled at a self-selected rate. Unimanual dexterity scores as measured with the Purdue Pegboard test (PPT) improved significantly more for the ACT and VC groups compared to the NC group. ACT lead to greater improvements than VC and NC in the assembly sub-test, which is a task that requires more advanced temporal and spatial processing. The ACT group improved significantly more than the VC group and non-significantly more than the NC group in cognitive planning ability as measured by the Tower of London test (ToL). There were also significant correlations between the assembly subtest of the PPT and all measures of the ToL. These correlations were stronger during post-testing than pre-testing. Pre-post changes in the combined PPT score and ToL number of correct moves correlated positively in the ACT group. These results support the efficacy of the salutary effects of ACT on global fine motor function and executive function in DS. Additionally, the performance on complex bimanual dexterity tasks appears to be related to the capacity of cognitive planning ability. This research has important implications for persons with movement deficits that affect activities of daily living.

Feasibility of Measuring Ventilatory Threshold in Adults With Stroke-Induced Hemiparesis: Implications for Exercise Prescription.

OBJECTIVES: To assess the feasibility of measuring ventilatory threshold (VT) in adults with walking impairments due to stroke. Secondary objectives are to assess reliability of VT over trials; assess whether participants could sustain treadmill walking at VT; and compare mean heart rate during sustained treadmill walking to estimated heart rate reserve (HRR). DESIGN: Cross-sectional, single-group design. SETTING: University research laboratory. PARTICIPANTS: Volunteer sample of adults (N=8) with impaired walking resulting from chronic stroke. INTERVENTIONS: Three submaximal treadmill walking tests on 3 separate days; a 30-minute treadmill walking session on a fourth day. MAIN OUTCOME MEASURES: Gas exchange variables were measured, and 2 independent observers identified VT. Mean heart rate response to treadmill walking at VT was measured and compared with estimated 40% of HRR. RESULTS: VT was measured successfully in 88% of all trials. There was no difference in VT among trials (P=.17). After multiple imputations to account for 3 missing data points, the intraclass correlation coefficient was .87 (95% confidence interval, .80-.95). All participants were able to walk for 20 minutes at VT. Mean ± SD heart rate during the session was 66.0%±8.0% of estimated maximal heart rate. There was no significant difference between mean heart rate and estimated HRR values (P=.70). CONCLUSIONS: In adults with impaired walking resulting from stroke, VT can be safely measured during submaximal treadmill walking. Participants were able to sustain walking at VT, and this value may provide an appropriate stimulus for aerobic exercise prescription in this population.