TY - JOUR
T1 - In-Vivo Study of Passive Musculotendon Mechanics in Chronic Hemispheric Stroke Survivors
AU - Chardon, Matthieu K.
AU - Suresh, Nina L.
AU - Dhaher, Yasin Y.
AU - Rymer, W. Zev
N1 - Funding Information:
Manuscript received September 10, 2019; revised December 22, 2019; accepted January 12, 2020. Date of publication March 5, 2020; date of current version April 8, 2020. This work was supported in part by the NIH under Grant R24 HD50821-07 and Grant R01HD089952-01A1. (Corresponding author: Matthieu K. Chardon.) Matthieu K. Chardon is with the Feinberg School of Medicine, North-western University, Chicago, IL 60611 USA (e-mail: m-chardon@ northwestern.edu).
Publisher Copyright:
© 2001-2011 IEEE.
PY - 2020/4
Y1 - 2020/4
N2 - We characterized the passive mechanical properties of the affected and contralateral musculotendon units in 9 chronic stroke survivors as well as in 6 neurologically-intact controls. Using a position-controlled motor, we precisely indented the distal tendon of the biceps brachii to a 20 mm depth from skin, recording both its sagittal motion using ultrasound movies and the compression force at the tip of the indenter. Length changes of 8 equally-spaced features along the aponeurosis axis were quantified using a pixel-tracking protocol. We report that, on the aggregate and with respect to contralateral and control, respectively, the affected side initiates feature motion at a shorter indentation distance by 61% and 50%, travels further by 15% and 9%, at a lower rate of 28% and 15%, and is stiffer by 40% and 57%. In an extended analysis including the spatial location of the 8 designated features, we report that in contrast to the contralateral and control muscles, the affected musculotendon unit does not strain measurably within the imaging window. These results confirm that chronic stroke-induced spasticity changes musculotendon unit passive mechanics, causing it to not strain under stretch. The mechanisms responsible for altered passive mechanics may lie within extracellular matrix fibrosis.
AB - We characterized the passive mechanical properties of the affected and contralateral musculotendon units in 9 chronic stroke survivors as well as in 6 neurologically-intact controls. Using a position-controlled motor, we precisely indented the distal tendon of the biceps brachii to a 20 mm depth from skin, recording both its sagittal motion using ultrasound movies and the compression force at the tip of the indenter. Length changes of 8 equally-spaced features along the aponeurosis axis were quantified using a pixel-tracking protocol. We report that, on the aggregate and with respect to contralateral and control, respectively, the affected side initiates feature motion at a shorter indentation distance by 61% and 50%, travels further by 15% and 9%, at a lower rate of 28% and 15%, and is stiffer by 40% and 57%. In an extended analysis including the spatial location of the 8 designated features, we report that in contrast to the contralateral and control muscles, the affected musculotendon unit does not strain measurably within the imaging window. These results confirm that chronic stroke-induced spasticity changes musculotendon unit passive mechanics, causing it to not strain under stretch. The mechanisms responsible for altered passive mechanics may lie within extracellular matrix fibrosis.
KW - Musculotendon mechanics
KW - robotic indenter
KW - stroke
KW - ultrasound imaging
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U2 - 10.1109/TNSRE.2020.2972206
DO - 10.1109/TNSRE.2020.2972206
M3 - Article
C2 - 32149642
AN - SCOPUS:85083285568
SN - 1534-4320
VL - 28
SP - 1022
EP - 1031
JO - IEEE Transactions on Neural Systems and Rehabilitation Engineering
JF - IEEE Transactions on Neural Systems and Rehabilitation Engineering
IS - 4
M1 - 9025193
ER -