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Objective: The aim of this study was to investigate: (1) the effects of a stroke on motor imagery vividness as measured by the Kinesthetic and Visual Imagery Questionnaire (KVIQ-20); (2) the influence of the lesion side; and (3) the symmetry of motor imagery., Methods: Thirty-two persons who had sustained a stroke, in the right (n = 19) or left (n = 13) cerebral hemisphere, and 32 age-matched healthy persons participated. The KVIQ-20 assesses on a 5-point ordinal scale the clarity of the image (visual scale) and the intensity of the sensations (kinesthetic scale) that the subjects are able to imagine from the first-person perspective., Results: In both groups, the visual scores were higher (P = .0001) than the kinesthetic scores and there was no group difference. Likewise, visual scores remained higher than kinesthetic scores irrespective of the lesion side. The visual scores poststroke were higher (P = .001) when imagining upper limb movements on the unaffected side than those on the affected side. When focusing on the lower limb only, however, the kinesthetic scores were higher (P = .001) when imagining movements of the unaffected compared to those on the affected side., Conclusions: The vividness of motor imagery poststroke remains similar to that of age-matched healthy persons and is not affected by the side of the lesion. However, after stroke motor imagery is not symmetrical and motor imagery vividness is better when imagining movements on the unaffected than on the affected side, indicating an overestimation possibly related to a hemispheric imbalance or a recalibration of motor imagery perception.

Objective: To examine the reproducibility of 2 chronometric tests: time-dependent motor imagery (TDMI) screening test and temporal congruence test., Design: Test-retest 10 to 14 days apart., Setting: Laboratory of a university-affiliated center for research in rehabilitation., Participants: Twenty persons post cerebrovascular accident (CVA) and 46 healthy persons (controls)., Intervention: The reproducibility of the TDMI screening test, wherein the number of stepping movements (performed in sitting) imagined over 15, 25, and 45 seconds is recorded, and of the temporal congruence test wherein the duration of physically executed (E) and imagined (I) stepping movements is recorded, was evaluated., Main Outcome Measures: The test-retest reliability of the number of imagined movements (TDMI screening test), movement duration and I/E time ratios (temporal congruence test), and intrasession reliability of the temporal congruence test were assessed by using intraclass correlation coefficients (ICCs)., Results: For the TDMI screening test, the ICCs ranged from .88 to .93 (CVA, n=20) and from .87 to .92 (controls, n=9). For the temporal congruence test, when the total duration of 2 series of 5 stepping movements was averaged, ICCs ranged from .76 to .97 (CVA, n=20) and from .77 to .93 (controls, n=46), whereas for 1 series the ICCs ranged from .71 to .95 and from .63 to .95 in the CVA and control groups, respectively. The ICCs for intrasession reliability for the CVA (n=20) and control (n=46) groups, respectively, ranged from .90 to .98 and .95 to .97., Conclusions: The present findings support the reproducibility of both tests in both groups. Mental chronometry can be used reliably for the screening of patients capable of motor imagery or for measuring temporal congruence between real and imagined movements poststroke.

Purpose: To benefit from mental practice training after stroke, one must be able to engage in motor imagery, and thus reliable motor imagery assessment tools tailored to persons with sensorimotor impairments are needed. The aims of this study were to (1) examine the test-retest reliability of the Kinesthetic and Visual Imagery Questionnaire (KVIQ-20) and its short version (the KVIQ-10) in healthy subjects and subjects with stroke, (2) investigate the internal consistency of both KVIQ versions, and (3) explore the factorial structure of the two KVIQ versions., Methods: The KVIQ assesses on a five-point ordinal scale the clarity of the image (visual: V subscale) and the intensity of the sensations (kinesthetic: K subscale) that the subjects are able to imagine from the first-person perspective. Nineteen persons who had sustained a stroke (CVA group) and 46 healthy persons (CTL group) including an age-matched (aCTL: n = 19) control group were assessed twice by the same examiner 10 to 14 days apart. The test-retest reliability was assessed using intraclass correlation coef- ficients (ICCs). The internal consistency (Cronbach alpha) and the factorial structure of both KVIQ versions were studied in a sample of 131 subjects., Results: In the CVA group, the ICCs ranged from 0.81 to 0.90, from 0.73 to 0.86 in the aCTL group, and from 0.72 to 0.81 in the CTL group. When imagining movements of the affected and unaffected limbs (upper and lower limbs combined) ICCs in the CVA group ranged, respectively, from 0.71 to.87 and from 0.86 to 0.94. Likewise, when imagining movement of the dominant and nondominant limbs, ICCs in the aCTL group ranged, respectively, from 0.75 to 0.89 and from 0.81 to.92. Cronbach a values were, respectively, 0.94 (V) and 0.92 (K) for the KVIQ-20 and 0.89 (V) and 0.87(K) for the KVIQ-10. The factorial analyses indicated that two factors explained 63.4% and 67.7% of total variance, respectively., Conclusion: Both versions of the KVIQ present similar psychometric properties that support their use in healthy individuals and in persons post-stroke. Because the KVIQ-10 can be administered in half the time, however, it is a good choice when assessing persons with physical disabilities.

This trial compares the effects of task-oriented physical therapy (PT) provided with and without the use of rehabilitation technology on locomotor recovery in 63 persons with subacute stroke. Participants in the experimental (EXP) group used a treadmill, a Kinetron isokinetic exerciser, and a limb-load monitor, whereas those in the control (CTL) group did not while engaging in PT 1 h per day, 5 days per week for 2 months. Locomotor recovery was assessed by clinical (gait speed, Fugl Meyer motor leg and arm subscores, the Balance Scale, the Timed Up and Go, and the Barthel ambulation subscore) and laboratory outcomes (gait kinematics and kinetics) pre- and posttherapy and 3 months later. Within groups, gait speed (P < 0.01) and all secondary measures improved posttherapy (P < 0.01-0.05), and improvements in clinical measures were maintained at follow-up, but there was no difference between groups (P > 0.05). When the groups were pooled, the increase in gait speed was associated (r = 0.52, P = 0.003) with an increase in ankle power generation of the affected leg. The results demonstrate that the efficacy of the task-oriented approach is not dependent on rehabilitation technology.

The ability to mentally simulate motor actions was studied in 25 patients with stroke. The duration of imagined and executed movements of the arm and leg was compared. Both executed and imagined movements took longer with the affected limbs than with the unaffected limbs. For both tasks, the duration of movements with the unaffected limbs was longer in the imagined than in the executed conditions, indicating a lack of temporal congruence on that side. Because the temporal uncoupling was found in the limbs contralateral to the intact hemisphere, we propose that this reflects a general slowing in motor imagery that is an indirect consequence of the lesion, rather than a deficit in movement representation within the unaffected hemisphere per se., (Copyright 2004 Lippincott Williams and Wilkins)

Objective: To investigate the effect of mental practice on the learning of a sequential task for the lower limb in a patient with a hemiparesis resulting from a stroke., Design: A single-case study., Setting: Research laboratory of a university-affiliated rehabilitation center., Patient: A right-handed 38-year-old man who had suffered a left hemorrhagic subcortical stroke 4 months prior., Intervention: The patient practiced a serial response time task with the lower limb in 3 distinct training phases over a period of 5 weeks: 2 weeks of physical practice, 1 week of combined physical and mental practice, and then 2 weeks of mental practice alone., Main Outcome Measures: Performance on the task measured through errors and response times. Imagery abilities measured through questionnaires., Results: The patient's average response time improved significantly during the 1st 5 days of physical practice (26%) but then failed to show further improvement during the following week of physical practice. The combination of mental and physical practice during the 3rd week yielded additional improvement (10.3%), whereas the following 2 weeks of mental practice resulted in a marginal increase in performance (2.2%)., Conclusion: The findings show that mental practice, when combined with physical practice, can improve the performance of a sequential motor skill in people who had a stroke, and suggest that mental practice could play a role in the retention of newly acquired abilities.

This study examines the potential of using mental practice (MP) to promote the learning of 2 mobility tasks in persons with stroke. Twelve patients were trained with MP to increase the loading of the affected limb while standing up from a chair and sitting down. Vertical forces were recorded using force plates under each foot and the chair. Changes in the loading of the affected limb and in task duration, immediately after 1 training session and 24 h later, served as outcomes. After training, the loading of the affected limb had increased (P < 0.001) during standing up (16.2%) and sitting down (17.9%), and the improvement remained significant 24 h later, indicating a learning effect. In contrast, the duration of the performance did not change with training. The results indicate that, in the early stage of learning with MP, changes in limb-loading strategies are a more sensitive measure of performance than is speed.

The aims of this study were to determine if the changes in impairment and disability measures for the upper and lower extremities were equivalent during the post-stroke rehabilitation period and whether the rates of change were maintained 6 months after discharge from rehabilitation. A prospective cohort study design was used. One-hundred-and-thirty-two people who had sustained a stroke and who were enrolled in an intensive functional rehabilitation programme were recruited. Upper and lower extremity impairments and disabilities were evaluated at admission, at discharge from rehabilitation and 6 months later. During active rehabilitation, the changes in both extremities were smaller for the impairment measures (standardized response mean (SRM), 0.37-0.63) than the disability measures (SRM, 0.76-1.05). While the changes in upper and lower extremities were equivalent for impairment measures, they were larger in the lower extremity for disability measures, indicating that the rate of functional improvement was faster in the lower extremity during active rehabilitation. After discharge, however, while the rate of motor recovery in the lower extremity dropped (SRM, 0.54-0.18), it was maintained in the upper extremity (SRM, 0.45 and 0.42). Present findings indicate that functional (disability) measures improve faster than impairment measures in both extremities during the active rehabilitation period and suggest that motor recovery occurs at a different rate in the upper and lower extremities, with that of the upper extremity occurring later and extending into the period after discharge from active rehabilitation.

Introduction: To assess mobility and locomotor coordination after stroke with the rise-to-walk task (RTW) and to examine the construct and concurrent validity of this task., Methods: Nineteen subjects who had sustained a stroke and 19 healthy subjects performed the RTW task. The performance was recorded simultaneously with 2 clinical methods and 1 instrumented method. The RTW duration and fluidity of the motor strategy (fluid or nonfluid) were compared between groups and between methods. The relationship between RTW duration and 3 locomotor-related disability tests, as well as 1 motor impairment test, was studied., Results: The subjects with stroke took 65% more time to complete the RTW task, and 16/19 separated the tasks of rising and walking (nonfluid strategy). Measures of the RTW duration with clinical methods were strongly correlated (r = 0.84 to 0.98) to those from the instrumented method, and the motor strategy was successfully assessed from video records. The duration was moderately correlated to scores from other locomotor-related tests, but not to the motor impairment test., Discussion: The assessment of mobility and locomotor coordination with the RTW task indicate that both outcomes are impaired after stroke and that clinical methods provide a valid measurement of the task.

This study investigated the role of paresis, excessive antagonist coactivation, increased muscle-tendon passive stiffness and spasticity in the reduced stance phase plantarflexor moment (Mmax) and swing phase dorsiflexion during gait (DFmax) in subjects with a recent (<6 months post-stroke) hemiparesis (patients). The gait pattern of the paretic and non-paretic sides was evaluated in 30 patients (aged 57.8+/-10.8 years), whereas only one side was evaluated in 15 healthy controls (aged 59.1+/-9.8 years) while walking at natural and very slow speeds. Peak plantarflexor moment (Mmax) and peak medial gastrocnemius (MG) activation during the stance phase, as well as peak dorsiflexion angle (Dfmax) and peak tibialis anterior (TA) activation during the swing phase, were retained for analysis. In addition, a coactivation index and a plantarflexor spasticity index were calculated for both the stance and the swing phase, and plantarflexor passive stiffness was evaluated on an isokinetic dynamometer. The results showed that Mmax on the paretic and non-paretic sides were both reduced compared with control values at natural speed. This reduction was combined to a low MG activation (paresis) on the paretic side. On the non-paretic side, the reduced plantarflexor moment was related to excessive coactivation levels. The swing phase Dfmax tended to be reduced (not significantly) on the paretic side of the patients compared with control values. This reduction was neither associated with excessive antagonist coactivation nor to plantarflexor hyperactive stretch reflexes, but rather to an increased plantarflexor passive stiffness. In some of the patients, however, an increased TA activation that overcame the plantarflexor passive stiffness allowed for normal DFmax values. The functional consequences of the disturbed mechanisms of motor control observed in both the paretic and non-paretic sides are discussed.

Objective: To examine 10-m comfortable walking speed and 6-minute distance in healthy individuals and individuals after stroke and to assess the level of disability associated with poor walking endurance after stroke., Design: Descriptive study in which comfortable walking speed over 10 m and distance covered in 6 minutes (6-minute walk test) were compared between healthy subjects and subjects after stroke., Subjects: Twelve healthy subjects and 14 subjects after stroke., Main Outcome Measures: Walking speed and 6-minute distances were compared between groups. In addition, for each group, actual distance walked in 6 minutes was compared with the distance predicted by the 10-m walking speed test and the distance predicted by normative reference equations., Results: Subjects after stroke had significant reductions in 10-m speed and 6-minute distance compared with healthy subjects (p < 0.05). Subjects after stroke were not able to maintain their comfortable walking speed for 6 minutes, whereas healthy subjects walked in excess of their comfortable speed for 6 minutes. The average distance walked in 6 minutes by individuals after stroke was only 49.8+/-23.9% of the distance predicted for healthy individuals with similar physical characteristics., Conclusion: In our subjects after stroke, walking speed over a short distance overestimated the distance walked in 6 minutes. Both walking speed and endurance need to be measured and trained during rehabilitation.

The aims of the present study were to quantify the impairment in ankle coactivation on the paretic and non-paretic sides of subjects with hemiparesis and to examine the relationship of ankle coactivation with postural instability, motor deficit of the paretic lower extremity and locomotor performance. Electromyography of the medial gastrocnemius (MG) and tibialis anterior (TA) muscles were recorded bilaterally during gait in 30 subjects (62.1+/-9.9 years) who had suffered a recent stroke (<6 months) as well as on one side of 17 healthy controls (59.3+/-9.1 years) walking at very slow speed. Ankle muscle coactivation was calculated by dividing the time of overlap between MG and TA signals (threshold of 20 microV) by the duration of the gait phases of interest: stance, swing, first and second double support sub-phases and single support sub-phase. The time spent in single support and the peak plantarflexor moment of force on the paretic side were used to measure, respectively, postural stability and dynamic strength of the paretic plantarflexors. The subjects with hemiparesis demonstrated less coactivation on the paretic side during the single support sub-phase (p<0.01) and more coactivation during first and second double support sub-phases on the non-paretic side (p<0.001) compared to control values. The patients with coactivation patterns that differed the most from controls were the patients with the more severe impairments and disabilities. While the reduced coactivation on the paretic side may contribute to poor postural stability and poor locomotor performance, the presence of excessive coactivation on the non-paretic side when both limbs were in ground contact may be an adaptation to help maintain postural stability during gait.

Objective: To measure the contribution of passive stiffness to the ankle plantarflexor moment during gait in subjects with hemiparesis early after stroke. The relationship of passive stiffness with gait speed was also examined., Design: Cross-sectional, descriptive., Patients and Other Participants: A sample of convenience of 14 patients (54.7+/-10.9 yrs) with a hemiparesis for less than 5 months and 11 healthy controls (50.6+/-11.6 yrs)., Main Outcome Measures: The contribution of passive stiffness to the plantarflexor moment during gait was obtained using moment-angle slope (stiffness) values. Total plantarflexor stiffness was measured during gait, and passive stiffness was measured during passive dorsiflexion imposed by an isokinetic dynamometer at velocities and ranges of movement matched with values recorded during the plantarflexor lengthening period of the stance phase. The contribution of passive stiffness was obtained by dividing the passive stiffness (dynamometer) by the total plantarflexor stiffness (gait)., Results: On the paretic side, passive stiffness contributed more (16.8%; range 2.9% to 49.6%) to total plantarflexor stiffness during gait compared (p<.01) with both the nonparetic side (7.3%) and control values (5.9%). This increased contribution on the paretic side resulted from a large muscle-tendon passive stiffness, a decreased active muscle contribution, or both. Although in some patients the increased passive component led to the development of a total plantarflexor stiffness that was within normal values, it did not in others either because the active component was very small or because limited dorsiflexion during the stance phase prevented the passive component tension to develop. The contribution of passive stiffness was not significantly (p>.05) related to gait speed in both the patients and the controls., Conclusions: The increased contribution of passive stiffness to total plantarflexor moment during gait likely acts as an adaptation for a defective muscle active component, helping ankle push-off at the end of the stance phase. Although this mechanism is effective in most of the patients, it cannot come into action if the dorsiflexion movement during the stance phase is prevented, for instance, by enhanced stretch reflexes.

This article discusses the assessment and treatment of gait disorders after stroke. After consideration of the effects (of the disturbed motor control resulting from stroke) on the gait movements and the expected rate of recovery of walking capacity, different methods of assessment are considered. Emphasis is placed on selecting the appropriate measurement tool according to the individual's level of function. Also, the need to measure walking performance under different environmental constraints and the importance of instrument responsiveness to change over the range of walking disabilities are discussed. Task-related training with the opportunity for large amounts of practice is recommended to improve walking performance after stroke.