Robotic and clinical evaluation of upper limb motor performance in patients with Friedreich's Ataxia: An observational study

Marco Germanotta, Gessica Vasco, Maurizio Petrarca, Stefano Rossi, Sacha Carniel, Enrico Bertini, Paolo Cappa, Enrico Castelli

Research output: Contribution to journalArticlepeer-review


Background: Friedreich's ataxia (FRDA) is the most common hereditary autosomal recessive form of ataxia. In this disease there is early manifestation of gait ataxia, and dysmetria of the arms and legs which causes impairment in daily activities that require fine manual dexterity. To date there is no cure for this disease. Some novel therapeutic approaches are ongoing in different steps of clinical trial. Development of sensitive outcome measures is crucial to prove therapeutic effectiveness. The aim of the study was to assess the reliability and sensitivity of quantitative and objective assessment of upper limb performance computed by means of the robotic device and to evaluate the correlation with clinical and functional markers of the disease severity. Methods: Here we assess upper limb performances by means of the InMotion Arm Robot, a robot designed for clinical neurological applications, in a cohort of 14 children and young adults affected by FRDA, matched for age and gender with 18 healthy subjects. We focused on the analysis of kinematics, accuracy, smoothness, and submovements of the upper limb while reaching movements were performed. The robotic evaluation of upper limb performance consisted of planar reaching movements performed with the robotic system. The motors of the robot were turned off, so that the device worked as a measurement tool. The status of the disease was scored using the Scale for the Assessment and Rating of Ataxia (SARA). Relationships between robotic indices and a range of clinical and disease characteristics were examined. Results: All our robotic indices were significantly different between the two cohorts except for two, and were highly and reliably discriminative between healthy and subjects with FRDA. In particular, subjects with FRDA exhibited slower movements as well as loss of accuracy and smoothness, which are typical of the disease. Duration of Movement, Normalized Jerk, and Number of Submovements were the best discriminative indices, as they were directly and easily measurable and correlated with the status of the disease, as measured by SARA. Conclusions: Our results suggest that outcome measures obtained by means of robotic devices can improve the sensitivity of clinical evaluations of patients' dexterity and can accurately and efficiently quantify changes over time in clinical trials, particularly when functional scales appear to be no longer sensitive.

Original languageEnglish
Article number41
JournalJournal of NeuroEngineering and Rehabilitation
Issue number1
Publication statusPublished - Apr 23 2015


  • Accuracy
  • Friedreich's ataxia
  • Kinematics
  • Reaching task
  • Robot-mediated evaluation
  • Scale for the Assessment and Rating of Ataxia
  • Smoothness
  • Submovements
  • Upper limb

ASJC Scopus subject areas

  • Rehabilitation
  • Health Informatics


Dive into the research topics of 'Robotic and clinical evaluation of upper limb motor performance in patients with Friedreich's Ataxia: An observational study'. Together they form a unique fingerprint.

Cite this