Improving proprioceptive deficits after stroke through robot-assisted training of the upper limb: a pilot case report study.

The purpose of this study was to determine whether a conventional robot-assisted therapy of the upper limb was able to improve proprioception and motor recovery of an individual after stroke who exhibited proprioceptive deficits. After robotic sensorimotor training, significant changes were observed in kinematic performance variables. Two quantitative parameters evaluating position sense improved after training. Range of motion during shoulder and wrist flexion improved, but only wrist flexion remained improved at 3-month follow-up. These preliminary results suggest that intensive robot-aided rehabilitation may play an important role in the recovery of sensory function. However, further studies are required to confirm these data.

Evaluation of upper limb sense of position in healthy individuals and patients after stroke.

The aims of this study were to develop and evaluate reliability of a quantitative assessment tool for upper limb sense of position on the horizontal plane. We evaluated 15 healthy individuals (controls) and 9 stroke patients. A robotic device passively moved one arm of the blindfolded participant who had to actively move his/her opposite hand to the mirror location in the workspace. Upper-limb's position was evaluated by a digital camera. The position of the passive hand was compared with the active hand's 'mirror' position. Performance metrics were then computed to measure the mean absolute errors, error variability, spatial contraction/expansion, and systematic shifts. No significant differences were observed between dominant and non-dominant active arms of controls. All performance parameters of the post-stroke group differed significantly from those of controls. This tool can provide a quantitative measure of upper limb sense of position, therefore allowing detection of changes due to rehabilitation.

Robot-aided neurorehabilitation in sub-acute and chronic stroke: does spontaneous recovery have a limited impact on outcome?

BACKGROUND: Robotic neurorehabilitation, thanks to high dosage/intensity training protocols, has the potential for a greater impact on impairment. OBJECTIVE: We aimed to analyze how time since the acute event may influence the motor recovery process during robot-assisted rehabilitation of the upper limb. METHODS: A total of 41 patients after stroke were enrolled: 20 in subacute phase, i.e. ≤ 6 months elapsed since their unilateral cerebrovascular accident (CVA), and 21 at chronic stage, i.e. > 6 months since CVA. All subjects underwent 30 minutes of robot-aided rehabilitation twice a day, 5 days a week for at least three weeks of training. Patients were evaluated at the start and end of treatment using the Fugl-Meyer and Modified Ashworth clinical scales and by a set of robot measured kinematic parameters. The time interval from stroke was considered as a grouping factor to analyze its impact on time course of recovery. RESULTS: After training both groups significantly improved their impairment (F = 44.25, p < 0.001) but sub-acute patients showed a greater improvement on the Fugl-Meyer scale than chronic patients. The time course of recovery of the kinematic variables showed higher time constants of motor improvement in the sub-acute than chronic group, but they were one order lower than spontaneous recovery time constants. CONCLUSIONS: Spontaneous recovery seems to have a limited impact on the improvement of sub-acute patients, most of their changes being likely due to re-learning during rehabilitation. In addition, a longer recovery time was required to maximize outcome in sub-acute than in chronic patients.

Lower limb spasticity assessment using an inertial sensor: a reliability study.

Spasticity is a common motor impairment in patients with neurological disorders that can prevent functional recovery after rehabilitation. In the clinical setting, its assessment is carried out using standardized clinical scales. The aim of this study was to verify the applicability of inertial sensors for an objective measurement of quadriceps spasticity and evaluate its test-retest and inter-rater reliability during the implementation of the Wartenberg pendulum test. Ten healthy subjects and 11 patients in vegetative state with severe brain damage were enrolled in this study. Subjects were evaluated three times on three consecutive days. The test-retest reliability of measurement was assessed in the first two days. The third day was devoted to inter-rater reliability assessment. In addition, the lower limb muscle tone was bilaterally evaluated at the knee joint by the modified Ashworth scale. The factorial ANOVA analysis showed that the implemented method allowed us to discriminate between healthy and pathological conditions. The fairly low SEM and high ICC values obtained for the pendulum parameters indicated a good test-retest and inter-rater reliability of measurement. This study shows that an inertial sensor can be reliably used to characterize leg kinematics during the Wartenberg pendulum test and provide quantitative evaluation of quadriceps spasticity.

Modeling upper limb clinical scales by robot-measured performance parameters.

The status of motor function in stroke survivors and the effect of any therapeutic intervention are generally measured by physiotherapists using clinical assessment scales that probe specific aspects of a subject's motor behavior. Although they are widely accepted, these measurement tools are limited by interrater and intrarater reliability and are time-consuming to apply. This paper analyzes the changes in movement kinematics and kinetics during robot-aided neurorehabilitation of subjects after stroke and verifies the possibility of estimating outcome measures by means of a set of robot measured parameters.

Development of a progressive task regulation algorithm for robot-aided rehabilitation.

Patient motivation is an important factor in rehabilitation. The difficulty level of the motor task, the awareness of the performance obtained, and the quantity and quality of feedbacks presented to the patient can influence patient motivation and produce different ways of acting and different performances. This study presents a Progressive Task Regulation algorithm able to evaluate the patient's performance during training and automatically change the features of the reaching movement, so as to adapt automatically the difficulty level of the motor task to the patient's ability. Use of the progressive task regulation algorithm should promote patient motivation throughout the course of treatment.