TY - JOUR
T1 - Inter-limb coupling in individuals with transtibial amputation during bilateral stance is direction dependent
AU - Raffalt, Peter C.
AU - Kent, Jenny A.
AU - Stergiou, Nick
N1 - Publisher Copyright:
© 2021 Elsevier B.V.
PY - 2021/10
Y1 - 2021/10
N2 - We investigated the control of upright standing in individuals with unilateral transtibial amputation (TTA) by assessing the inter-limb coupling and the coupling between the center of pressure beneath both limbs combined (COPNET) and the center of pressure (COP) beneath the prosthetic limb and the intact limb. Twenty-one adults with TTA and eighteen unimpaired adults completed 90 s of standing on two parallel force plates. The inter-limb coupling and the coupling between the COP beneath each limb and the COPNET were assessed by quantifying the synchronization of the COP signals. This included the number of epochs with synchronized signals, the total duration of signal synchronization and the relative phase and deviation phase between the signals. Additionally, magnitude and temporal characteristics of the COP displacements were quantified. Individuals with TTA exhibited looser inter-limb coupling in the anterior-posterior direction, characterized by more shifts between epochs with synchronized signals, shorter total duration of signal synchronization, less in-phase coordination patterns and a higher deviation phase between the two limbs, compared to unimpaired individuals. This coincided with a larger and more irregular postural sway in the TTA group. No group difference was observed in the mediolateral direction. The coupling between the COPNET and the COP beneath the individual limbs was similarly direction dependent, and tighter for the intact side, suggesting that an intact limb-driven strategy was utilized.
AB - We investigated the control of upright standing in individuals with unilateral transtibial amputation (TTA) by assessing the inter-limb coupling and the coupling between the center of pressure beneath both limbs combined (COPNET) and the center of pressure (COP) beneath the prosthetic limb and the intact limb. Twenty-one adults with TTA and eighteen unimpaired adults completed 90 s of standing on two parallel force plates. The inter-limb coupling and the coupling between the COP beneath each limb and the COPNET were assessed by quantifying the synchronization of the COP signals. This included the number of epochs with synchronized signals, the total duration of signal synchronization and the relative phase and deviation phase between the signals. Additionally, magnitude and temporal characteristics of the COP displacements were quantified. Individuals with TTA exhibited looser inter-limb coupling in the anterior-posterior direction, characterized by more shifts between epochs with synchronized signals, shorter total duration of signal synchronization, less in-phase coordination patterns and a higher deviation phase between the two limbs, compared to unimpaired individuals. This coincided with a larger and more irregular postural sway in the TTA group. No group difference was observed in the mediolateral direction. The coupling between the COPNET and the COP beneath the individual limbs was similarly direction dependent, and tighter for the intact side, suggesting that an intact limb-driven strategy was utilized.
KW - Center of pressure dynamics
KW - Phase synchronization
KW - Postural control
KW - Prosthesis
UR - http://www.scopus.com/inward/record.url?scp=85112473377&partnerID=8YFLogxK
U2 - 10.1016/j.humov.2021.102861
DO - 10.1016/j.humov.2021.102861
M3 - Article
C2 - 34392188
AN - SCOPUS:85112473377
SN - 0167-9457
VL - 79
JO - Human Movement Science
JF - Human Movement Science
M1 - 102861
ER -