Details
| Original language | English |
|---|---|
| Pages (from-to) | 269-276 |
| Number of pages | 8 |
| Journal | Computers in Biology and Medicine |
| Volume | 103 |
| Early online date | 1 Nov 2018 |
| Publication status | Published - 1 Dec 2018 |
| Externally published | Yes |
Abstract
Background: Muscles of individuals with Cerebral Palsy (CP) undergo structural changes over their lifespan including an increase in muscle stiffness, decreased strength and coordination. Being able to identify these changes non-invasively would be beneficial to improve understanding of CP and assess therapy effectiveness over time. This study aims to adapt an existing EMG-driven Hill-type muscle model for neuromuscular characterisation during isometric contractions of the elbow joint. Methods: Participants with (n = 2) and without CP (n = 8) performed isometric force ramps with contraction levels ranging between 15 and 70% of their maximum torque. During these contractions, high-density EMG data were collected from the M. Biceps and Triceps brachii with 64 electrodes on each muscle. The EMG-driven Hill-type muscle model was used to predict torques around the elbow joint, and muscle characterisation was performed by applying a genetic algorithm that tuned individuals’ parameters to reduce the RMS error between observed and predicted torque data. Results: Observed torques could be predicted accurately with an overall mean error of 1.24Nm ± 0.53Nm when modelling individual force ramps. The first four parameters of the model could be identified relatively reliably across different experimental protocols with a full-scale variation of below 20%. Conclusion: An HD-EMG muscle modelling approach to evaluating neuromuscular properties in participants with and without CP has been presented. This pilot study confirms the feasibility of the experimental protocol and demonstrates some parameters can be identified robustly using the isometric contraction force ramps.
Keywords
- Cerebral palsy, Electromyography, Force ramp, HD-EMG, Hill-type muscle model, Isometric contraction, Musculoskeletal modelling, Neuromuscular characterisation
ASJC Scopus subject areas
- Medicine(all)
- Health Informatics
- Computer Science(all)
- Computer Science Applications
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In: Computers in Biology and Medicine, Vol. 103, 01.12.2018, p. 269-276.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Neuromuscular characterisation in Cerebral Palsy using hybrid Hill-type models on isometric contractions
AU - Wiedemann, L. G.
AU - Jayaneththi, V. R.
AU - Kimpton, J.
AU - Müller, Matthias A.
AU - Wilson, N. C.
AU - Mcdaid, A. J.
AU - Chan, A.
AU - Hogan, A.
AU - Lim, E.
N1 - Funding information: This research was supported by the Marsden Fund (reference number: 3706165 ), managed by the Royal Society of New Zealand. The funding source did not have any involvement in the study design, data collection, analysis, interpretation of the data, writing of the report and in the decision to submit the work for publication.
PY - 2018/12/1
Y1 - 2018/12/1
N2 - Background: Muscles of individuals with Cerebral Palsy (CP) undergo structural changes over their lifespan including an increase in muscle stiffness, decreased strength and coordination. Being able to identify these changes non-invasively would be beneficial to improve understanding of CP and assess therapy effectiveness over time. This study aims to adapt an existing EMG-driven Hill-type muscle model for neuromuscular characterisation during isometric contractions of the elbow joint. Methods: Participants with (n = 2) and without CP (n = 8) performed isometric force ramps with contraction levels ranging between 15 and 70% of their maximum torque. During these contractions, high-density EMG data were collected from the M. Biceps and Triceps brachii with 64 electrodes on each muscle. The EMG-driven Hill-type muscle model was used to predict torques around the elbow joint, and muscle characterisation was performed by applying a genetic algorithm that tuned individuals’ parameters to reduce the RMS error between observed and predicted torque data. Results: Observed torques could be predicted accurately with an overall mean error of 1.24Nm ± 0.53Nm when modelling individual force ramps. The first four parameters of the model could be identified relatively reliably across different experimental protocols with a full-scale variation of below 20%. Conclusion: An HD-EMG muscle modelling approach to evaluating neuromuscular properties in participants with and without CP has been presented. This pilot study confirms the feasibility of the experimental protocol and demonstrates some parameters can be identified robustly using the isometric contraction force ramps.
AB - Background: Muscles of individuals with Cerebral Palsy (CP) undergo structural changes over their lifespan including an increase in muscle stiffness, decreased strength and coordination. Being able to identify these changes non-invasively would be beneficial to improve understanding of CP and assess therapy effectiveness over time. This study aims to adapt an existing EMG-driven Hill-type muscle model for neuromuscular characterisation during isometric contractions of the elbow joint. Methods: Participants with (n = 2) and without CP (n = 8) performed isometric force ramps with contraction levels ranging between 15 and 70% of their maximum torque. During these contractions, high-density EMG data were collected from the M. Biceps and Triceps brachii with 64 electrodes on each muscle. The EMG-driven Hill-type muscle model was used to predict torques around the elbow joint, and muscle characterisation was performed by applying a genetic algorithm that tuned individuals’ parameters to reduce the RMS error between observed and predicted torque data. Results: Observed torques could be predicted accurately with an overall mean error of 1.24Nm ± 0.53Nm when modelling individual force ramps. The first four parameters of the model could be identified relatively reliably across different experimental protocols with a full-scale variation of below 20%. Conclusion: An HD-EMG muscle modelling approach to evaluating neuromuscular properties in participants with and without CP has been presented. This pilot study confirms the feasibility of the experimental protocol and demonstrates some parameters can be identified robustly using the isometric contraction force ramps.
KW - Cerebral palsy
KW - Electromyography
KW - Force ramp
KW - HD-EMG
KW - Hill-type muscle model
KW - Isometric contraction
KW - Musculoskeletal modelling
KW - Neuromuscular characterisation
UR - http://www.scopus.com/inward/record.url?scp=85056205303&partnerID=8YFLogxK
U2 - 10.1016/j.compbiomed.2018.10.027
DO - 10.1016/j.compbiomed.2018.10.027
M3 - Article
VL - 103
SP - 269
EP - 276
JO - Computers in Biology and Medicine
JF - Computers in Biology and Medicine
SN - 0010-4825
ER -