Self-Paced Reaching after Stroke: A Quantitative Assessment of Longitudinal and Directional Sensitivity Using the H-Man Planar Robot for Upper Limb Neurorehabilitation.
Technology aided measures offer a sensitive, accurate and time-efficient approach for the assessment of sensorimotor function after neurological insult compared to standard clinical assessments. This study investigated the sensitivity of robotic measures to capture differences in planar reaching movements as a function of neurological status (stroke, healthy), direction (front, ipsilateral, contralateral), movement segment (outbound, inbound), and time (baseline, post-training, 2-week follow-up) using a planar, two-degrees of freedom, robotic-manipulator (H-Man). Twelve chronic stroke (age: 55 ± 10.0 years, 5 female, 7 male, time since stroke: 11.2 ± 6.0 months) and nine aged-matched healthy participants (age: 53 ± 4.3 years, 5 female, 4 male) participated in this study. Both healthy and stroke participants performed planar reaching movements in contralateral, ipsilateral and front directions with the H-Man, and the robotic measures, spectral arc length (SAL), normalized time to peak velocities (TpeakN), and root-mean square error (RMSE) were evaluated. Healthy participants went through a one-off session of assessment to investigate the baseline. Stroke participants completed a 2-week intensive robotic training plus standard arm therapy (8 × 90 min sessions). Motor function for stroke participants was evaluated prior to training (baseline, week-0), immediately following training (post-training, week-2), and 2-weeks after training (follow-up, week-4) using robotic assessment and the clinical measures Fugl-Meyer Assessment (FMA), Activity-Research-Arm Test (ARAT), and grip-strength. Robotic assessments were able to capture differences due to neurological status, movement direction, and movement segment. Movements performed by stroke participants were less-smooth, featured longerTpeakN, and larger RMSE values, compared to healthy controls. Significant movement direction differences were observed, with improved reaching performance for the front, compared to ipsilateral and contralateral movement directions. There were group differences depending on movement segment. Outbound reaching movements were smoother and featured longerTpeakNvalues than inbound movements for control participants, whereas SAL,TpeakN, and RMSE values were similar regardless of movement segment for stroke patients. Significant change in performance was observed between initial and post-assessments using H-Man in stroke participants, compared to conventional scales which showed no significant difference. Results of the study indicate the potential of H-Man as a sensitive tool for tracking changes in performance compared to ordinal scales (i.e., FM, ARAT).
Robotics Research Centre, School of Mechanical and Aerospace Engineering, Nanyang Technological University Singapore, Singapore.
Asif
A
Hussain
Robotics Research Centre, School of Mechanical and Aerospace Engineering, Nanyang Technological UniversitySingapore, Singapore; Interdisciplinary Graduate School, Nanyang Technological UniversitySingapore, Singapore.
Aamani
A
Budhota
Robotics Research Centre, School of Mechanical and Aerospace Engineering, Nanyang Technological UniversitySingapore, Singapore; Department of Kinesiology, San Francisco State UniversitySan Francisco, CA, USA; Health Equity Institute, San Francisco State UniversitySan Francisco, CA, USA.
Charmayne Mary Lee
CM
Hughes
Robotics Research Centre, School of Mechanical and Aerospace Engineering, Nanyang Technological UniversitySingapore, Singapore; Department of Bioengineering, Imperial College of Science, Technology and MedicineLondon, UK.
Wayne D
WD
Dailey
Centre for Advanced Rehabilitation Therapeutics, Tan Tock Seng Hospital Rehabilitation Centre Singapore, Singapore.
Deshmukh A
DA
Vishwanath
Centre for Advanced Rehabilitation Therapeutics, Tan Tock Seng Hospital Rehabilitation Centre Singapore, Singapore.
Christopher W K
CW
Kuah
Centre for Advanced Rehabilitation Therapeutics, Tan Tock Seng Hospital Rehabilitation Centre Singapore, Singapore.
Lester H L
LH
Yam
Centre for Advanced Rehabilitation Therapeutics, Tan Tock Seng Hospital Rehabilitation Centre Singapore, Singapore.
Yong J
YJ
Loh
School of Physical and Mathematical Sciences, Nanyang Technological University Singapore, Singapore.
Liming
L
Xiang
Centre for Advanced Rehabilitation Therapeutics, Tan Tock Seng Hospital Rehabilitation Centre Singapore, Singapore.
Karen S G
KS
Chua
Department of Bioengineering, Imperial College of Science, Technology and Medicine London, UK.
Etienne
E
Burdet
Robotics Research Centre, School of Mechanical and Aerospace Engineering, Nanyang Technological University Singapore, Singapore.
Domenico
D
Campolo
neurorehabilitation; robotic assessment; sensorimotor assessment; stroke; stroke rehabilitation