Article

A recent study reporting significantly reduced symmetry in arm swing
amplitude in early Parkinson's disease (PD), as measured during single strides in
a gait laboratory, led to this investigation of arm swing symmetry and
coordination over many strides using wearable accelerometers in PD. METHODS:
Forearm accelerations were recorded while eight early PD subjects and eight
Controls performed 8-min walking trials. Arm swing asymmetry (ASA), maximal
cross-correlation (MXC), and instantaneous relative phase (IRP) of bilateral arm
swing were compared between PD and Controls. Correlations between arm swing
measurements (ASA and MXC) and Unified PD Rating Scale (UPDRS) scores were
estimated. RESULTS: PD subjects demonstrated significantly higher ASA (p=0.002)
and lower MXC (p<0.001) than Controls. The IRP probability distribution for PD
was significantly different than Controls (p<0.001), with an angular standard
deviation of 67.2 degrees for PD and 50.6 degrees for Controls. Among PD
subjects, ASA was significantly correlated with the UPDRS score for the limbs
(R(2)=0.58, p=0.049), whereas MXC was significantly correlated with the tremor
subscore of the limbs (R(2)=0.64, p=0.031). DISCUSSION: The study confirms
previously reported higher arm swing asymmetry in PD but also shows there is
significantly lower MXC and greater IRP variability, suggesting that reduction in
bilateral arm coordination may contribute to clinically observed asymmetry in PD.
The differential correlation of clinical measures of motor disability with
measurements of arm swing during gait is intriguing and deserves further
investigation.
CI - Copyright A(c) 2011 Elsevier B.V. All rights reserved.

Langue : ANGLAIS