The reliability and validity of the Korean version of the reaching performance scale for stroke after translation and cross-cultural adaptation

The reaching performance scale for stroke evaluates reach-to grasp movement of the upper extremity and compensatory movements. The objective of the study was to translate and cross-culturally adapt the reaching performance scale for stroke into Korean and assess its reliability and validity. An expert committee supervised the forward and backward translation and the final translated Korean version of reaching performance scale for stroke (K-RPSS). Ninety-eight individuals (mean age 63.63 ± 13.13 years), with hemiplegia after stroke (97.82 ± 191.50 weeks) were evaluated independently by physiatrist and occupational therapist using K-RPSS. Degree of the motor impairment and functional status of patients were evaluated with the Fugl-Meyer assessment for upper limb and manual function test. The K-RPSS demonstrated excellent intra-rater (intraclass correlation coefficient = 0.9865), inter-rater (intraclass correlation coefficient 0.9866) reliability, and internal consistency (Cronbach α = 0.977 for total score). The validity of K-RPSS was confirmed with strong correlation with Fugl-Meyer assessment and manual function test. The K-RPSS had ceiling effect and the 3 points is the score change needed to indicate a change in a patient. K-RPSS has been shown to be a reliable and valid tool for assessing the compensation and movement quality of the upper limb and trunk when performing a reach-to grasp task. The K-RPSS is expected to be used widely by Korean speaking clinicians and researchers.

Muscle Synergies-Based Characterization and Clustering of Poststroke Patients in Reaching Movements

Background

A deep characterization of neurological patients is a crucial step for a detailed knowledge of the pathology and maximal exploitation and customization of the rehabilitation therapy. The muscle synergies analysis was designed to investigate how muscles coactivate and how their eliciting commands change in time during movement production. Few studies investigated the value of muscle synergies for the characterization of neurological patients before rehabilitation therapies. In this article, the synergy analysis was used to characterize a group of chronic poststroke hemiplegic patients.

Methods

Twenty-two poststroke patients performed a session composed of a sequence of 3D reaching movements. They were assessed through an instrumental assessment, by recording kinematics and electromyography to extract muscle synergies and their activation commands. Patients’ motor synergies were grouped by the means of cluster analysis. Consistency and characterization of each cluster was assessed and clinically profiled by comparison with standard motor assessments.

Results

Motor synergies were successfully extracted on all 22 patients. Five basic clusters were identified as a trade-off between clustering precision and synthesis power, representing: healthy-like activations, two shoulder compensatory strategies, two elbow predominance patterns. Each cluster was provided with a deep characterization and correlation with clinical scales, range of motion, and smoothness.

Conclusion

The clustering of muscle synergies enabled a pretherapy characterization of patients. Such technique may affect several aspects of the therapy: prediction of outcomes, evaluation of the treatments, customization of doses, and therapies.