Functional and gait assessment in children with Friedreich ataxia: Comparison of quantitative and functional evaluation

Abstract

s / Gait & Posture 42S (2015) S1–S90 S45 (Rimini, Italy).Motricity Index (MI), Trunk Control Test (TCT), Functional Ambulation Category (FAC), Walking Handicap Scale (WHS), Rivermead Mobility Index (RMI), Cumulative Illness Rating Scale (SI and CI), Timed-Up and Go Test (TUG) and Two Minute Walk Test (2MWT) were administered to subjects by the same operators. The 2MWT was administered with the addition of an IMU located on the trunk, at the height of the fifth lumbar vertebra. Four gait stability measures, namely Harmonic Ratio (HR), Index of Harmonicity (IH), Multiscale Entropy (MSE), and Recurrence Quantification Analysis (RQA), were calculated on trunk acceleration signal during gait obtained from 2MWT. Each measure was calculated for anterior-posterior (AP), mediolateral (ML) and vertical (V) acceleration directions. Log transformed measures were then used as inputs for linear regression models. Results: Subjects who used a cane showed a high correlation between MSE, RQA and TCT, RMI. More sparse but significant correlation has been found between MSE and WHS, CIRS. IH showed no correlation with clinical parameters. Subjects who were able to walk without a cane showed high correlation values betweenMSE, RQA and TUG, 2MWT and WHS. TUG, 2MWT and SI correlated in a lesser extent with HR. IH showed high correlation values with TUG and RMI; RMI correlated with MSE and RQA also. Discussion and conclusions: In subjects who walked with a cane, correlations between TCT and MSE were particularly consistent, highlighting an affinity between the instrumental measure of complexity of trunk acceleration and the clinical assessment of trunk control. For subjects who were able to walk without a cane TUG, 2MWT showed high correlations with stability measures, in particular with MSE and RQA (mainly in the ML direction), highlighting the importance of the medio-lateral control of the trunk during gait. In conclusion, gait stability measures based on trunk accelerations (in particular MSE and RQA) showed promising correlation with clinical scales in stroke patients, and could complement the standard clinical scores in the assessment of locomotor performance of subjects with stroke, helping clinicians and physical therapists in the patient’s rehabilitation process. Moreover, the use of instrumental measurements could lead, in the future, to a more reliable quantification of locomotor features, allowing avoiding inter-operator differences.