Abstract
Anticipatory postural adjustments (APAs) precede gait initiation and function to accelerate the center of mass forward and towards the initial stance leg. Impairments in APA generation, such as those seen in people with Parkinson's disease (PD), can impact the quality of the first step. An initial burst of activity in the dorsiflexor muscle (tibialis anterior) of the stepping leg is an important contributor to the posterior excursion of the center of pressure that accelerates the center of mass forward during an APA. Tibialis anterior activation can be diminished or absent in people with PD; however, the neuromechanical consequence of this diminished dorsiflexor torque on APA generation is not fully understood. Computational models of gait initiation that include components of the neuromuscular system may provide additional insight. In this paper, an inverted pendulum model of the body generated from healthy young adult data was used to simulate reduced dorsiflexor torque during an APA for gait initiation. Forward body lean angle and center of pressure were assessed over various settings of decreased dorsiflexor torque and compared to experimental data from a person with PD. Results from the model demonstrate that reducing the peak dorsiflexor torque by as little as 8-Nm may alter forward body lean and the center of pressure excursion from their nominal trajectories. These results can help inform how much torque is needed from an external device to effectively modulate APAs for gait initiation, as well as provide insight into compensation strategies for reduced dorsiflexor torque in pathology.
| Original language | English (US) |
|---|---|
| Article number | 8486966 |
| Pages (from-to) | 2210-2216 |
| Number of pages | 7 |
| Journal | IEEE Transactions on Neural Systems and Rehabilitation Engineering |
| Volume | 26 |
| Issue number | 11 |
| DOIs | |
| State | Published - Nov 2018 |
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Keywords
- Computational modeling
- Parkinson's disease
- anticipatory postural adjustments
Cite this
A neuromechanical model of reduced dorsiflexor torque during the anticipatory postural adjustments of gait initiation. / Petrucci, Matthew N.; Diberardino, Louis A.; MacKinnon, Colum D.; Hsiao-Wecksler, Elizabeth T.
In: IEEE Transactions on Neural Systems and Rehabilitation Engineering, Vol. 26, No. 11, 8486966, 11.2018, p. 2210-2216.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - A neuromechanical model of reduced dorsiflexor torque during the anticipatory postural adjustments of gait initiation
AU - Petrucci, Matthew N.
AU - Diberardino, Louis A.
AU - MacKinnon, Colum D.
AU - Hsiao-Wecksler, Elizabeth T.
PY - 2018/11
Y1 - 2018/11
N2 - Anticipatory postural adjustments (APAs) precede gait initiation and function to accelerate the center of mass forward and towards the initial stance leg. Impairments in APA generation, such as those seen in people with Parkinson's disease (PD), can impact the quality of the first step. An initial burst of activity in the dorsiflexor muscle (tibialis anterior) of the stepping leg is an important contributor to the posterior excursion of the center of pressure that accelerates the center of mass forward during an APA. Tibialis anterior activation can be diminished or absent in people with PD; however, the neuromechanical consequence of this diminished dorsiflexor torque on APA generation is not fully understood. Computational models of gait initiation that include components of the neuromuscular system may provide additional insight. In this paper, an inverted pendulum model of the body generated from healthy young adult data was used to simulate reduced dorsiflexor torque during an APA for gait initiation. Forward body lean angle and center of pressure were assessed over various settings of decreased dorsiflexor torque and compared to experimental data from a person with PD. Results from the model demonstrate that reducing the peak dorsiflexor torque by as little as 8-Nm may alter forward body lean and the center of pressure excursion from their nominal trajectories. These results can help inform how much torque is needed from an external device to effectively modulate APAs for gait initiation, as well as provide insight into compensation strategies for reduced dorsiflexor torque in pathology.
AB - Anticipatory postural adjustments (APAs) precede gait initiation and function to accelerate the center of mass forward and towards the initial stance leg. Impairments in APA generation, such as those seen in people with Parkinson's disease (PD), can impact the quality of the first step. An initial burst of activity in the dorsiflexor muscle (tibialis anterior) of the stepping leg is an important contributor to the posterior excursion of the center of pressure that accelerates the center of mass forward during an APA. Tibialis anterior activation can be diminished or absent in people with PD; however, the neuromechanical consequence of this diminished dorsiflexor torque on APA generation is not fully understood. Computational models of gait initiation that include components of the neuromuscular system may provide additional insight. In this paper, an inverted pendulum model of the body generated from healthy young adult data was used to simulate reduced dorsiflexor torque during an APA for gait initiation. Forward body lean angle and center of pressure were assessed over various settings of decreased dorsiflexor torque and compared to experimental data from a person with PD. Results from the model demonstrate that reducing the peak dorsiflexor torque by as little as 8-Nm may alter forward body lean and the center of pressure excursion from their nominal trajectories. These results can help inform how much torque is needed from an external device to effectively modulate APAs for gait initiation, as well as provide insight into compensation strategies for reduced dorsiflexor torque in pathology.
KW - Computational modeling
KW - Parkinson's disease
KW - anticipatory postural adjustments
UR - http://www.scopus.com/inward/record.url?scp=85054667354&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85054667354&partnerID=8YFLogxK
U2 - 10.1109/TNSRE.2018.2874991
DO - 10.1109/TNSRE.2018.2874991
M3 - Article
C2 - 30307872
AN - SCOPUS:85054667354
VL - 26
SP - 2210
EP - 2216
JO - IEEE Transactions on Neural Systems and Rehabilitation Engineering
JF - IEEE Transactions on Neural Systems and Rehabilitation Engineering
SN - 1534-4320
IS - 11
M1 - 8486966
ER -