Journal article
Predicting human chronically paralyzed muscle force : a comparison of three mathematical models
Journal of applied physiology (1985), Vol.100(3), pp.1027-1036
2006
DOI: 10.1152/japplphysiol.00935.2005
PMCID: PMC3274555
PMID: 16306255
Abstract
Chronic spinal cord injury (SCI) induces detrimental musculoskeletal adaptations that adversely affect health status, ranging from muscle paralysis and skin ulcerations to osteoporosis. SCI rehabilitative efforts may increasingly focus on preserving the integrity of paralyzed extremities to maximize health quality using electrical stimulation for isometric training and/or functional activities. Subject-specific mathematical muscle models could prove valuable for predicting the forces necessary to achieve therapeutic loading conditions in individuals with paralyzed limbs. Although numerous muscle models are available, three modeling approaches were chosen that can accommodate a variety of stimulation input patterns. To our knowledge, no direct comparisons between models using paralyzed muscle have been reported. The three models include 1) a simple second-order linear model with three parameters and 2) two six-parameter nonlinear models (a second-order nonlinear model and a Hill-derived nonlinear model). Soleus muscle forces from four individuals with complete, chronic SCI were used to optimize each model's parameters (using an increasing and decreasing frequency ramp) and to assess the models' predictive accuracies for constant and variable (doublet) stimulation trains at 5, 10, and 20 Hz in each individual. Despite the large differences in modeling approaches, the mean predicted force errors differed only moderately (8-15% error; P=0.0042), suggesting physiological force can be adequately represented by multiple mathematical constructs. The two nonlinear models predicted specific force characteristics better than the linear model in nearly all stimulation conditions, with minimal differences between the two nonlinear models. Either nonlinear mathematical model can provide reasonable force estimates; individual application needs may dictate the preferred modeling strategy.
Details
- Title: Subtitle
- Predicting human chronically paralyzed muscle force : a comparison of three mathematical models
- Creators
- Laura A FREY LAW - Graduate Program in Physical Therapy and Rehabilitation Science, The University of Iowa, Iowa City, Iowa, United StatesRichard K SHIELDS - Graduate Program in Physical Therapy and Rehabilitation Science, The University of Iowa, Iowa City, Iowa, United States
- Resource Type
- Journal article
- Publication Details
- Journal of applied physiology (1985), Vol.100(3), pp.1027-1036
- DOI
- 10.1152/japplphysiol.00935.2005
- PMID
- 16306255
- PMCID
- PMC3274555
- NLM abbreviation
- J Appl Physiol (1985)
- ISSN
- 8750-7587
- eISSN
- 1522-1601
- Publisher
- American Physiological Society; Bethesda, MD
- Language
- English
- Date published
- 2006
- Academic Unit
- Orthopedics and Rehabilitation; Nursing; Physical Therapy and Rehabilitation Science
- Record Identifier
- 9984047867902771
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