title: Distributed moment histogram: a neurophysiology based method of agonist and antagonist trunk muscle activity prediction.
abstract: A neurocortical-based technique of muscle recruitment is presented to solve the muscle indeterminacy problem for lumbar torso modeling. Cortical recordings from behaving primates have established motor cortex cells that respond to a wide range of task directions, but are tuned to a preferred direction. A characteristic activity pattern of these neurons seems to be associated with effort direction. It was hypothesized that a model which recruits muscles based on a similar distribution would predict antagonistic muscle activity with greater realism than a widely referenced optimization formulation. The predictions of the Distributed Moment Histogram (DMH) method were evaluated under common speed (< 30 degrees s-1) sagittal plane lifting conditions using five subjects. The predicted forces showed high correspondence with agonist and antagonist myoelectric patterns. The mean coefficient of determination for the erector spinae was r2 = 0.91, and 0.41 for the latissimus. For the antagonistic muscles, the rectus abdominus was found to be electrically silent (< 3% MVC) and no activity was predicted by the method. The external oblique muscle was observed to be minimally active (< 16% MVC), and the DMH method predicted its mostly constant activity with a mean standard error of 1.6% MVC. The realistic antagonistic predictions supported the hypothesis and justify this cortical based technique as an alternative for muscle tension estimation in biomechanical torso modeling. A primary advantage of this method is its computational simplicity and direct physiologic analog.
authors.affiliation: Department of Industrial and Operations Engineering, University of Michigan, Ann Arbor 48109-2117, USA.
authors.forename: U
authors.initials: U
authors.lastname: Raschke
authors.forename: B J
authors.initials: BJ
authors.lastname: Martin
authors.forename: D B
authors.initials: DB
authors.lastname: Chaffin
mesh_terms: D000009:Abdominal Muscles / Q000294:innervation / Q000502:physiology*; D000328:Adult; D001415:Back; D001696:Biomechanical Phenomena; D004576:Electromyography; D005544:Forecasting; D006801:Humans; D017770:Lifting; D008159:Lumbar Vertebrae; D008297:Male; D009044:Motor Cortex / Q000502:physiology; D009046:Motor Neurons / Q000502:physiology; D009068:Movement; D009119:Muscle Contraction / Q000502:physiology*; D009470:Muscle Spindles / Q000502:physiology; D018482:Muscle, Skeletal / Q000294:innervation / Q000502:physiology*; D009482:Neurophysiology; D005082:Physical Exertion / Q000502:physiology; D017568:Rectus Abdominis / Q000502:physiology; D012680:Sensitivity and Specificity