title: Non-invasive isometric force measurement of plantar flexors in rats.
abstract: BACKGROUND
  Isometric muscle force measurement is a sensitive marker for motor function recovery in rat nerve repair models. Current methods of eliciting maximal isometric force with nerve stimulation cannot provide longitudinal data.
  
  
  METHODS
  We developed a novel method for measuring isometric muscle force with a device designed to allow minimally invasive nerve stimulation and measurement of plantar flexion force. This indirectly elicited muscle force was compared with muscle force elicited by direct muscle stimulation in 3 surgical models.
  
  
  RESULTS
  The force measured after sciatic nerve transection and repair followed a parabolic trend. There was a postinjury decrease in force that continued until postoperative day 42, after which the force increased with time, indicating muscle reinnervation.
  
  
  CONCLUSIONS
  This approach can track longitudinal changes in force in the most common animal model for studies of clinically relevant problems in the peripheral nerve field.
authors.affiliation: Department of Neurologic Surgery, Mayo Clinic, 200 First Street SW, Rochester, Minnesota, 55905.
authors.forename: Aditya
authors.initials: A
authors.lastname: Chawla
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Spinner
authors.forename: Michael
authors.initials: M
authors.lastname: Torres Lizardi
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Yaszemski
authors.forename: Anthony J
authors.initials: AJ
authors.lastname: Windebank
authors.forename: Huan
authors.initials: H
authors.lastname: Wang
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D015331:Cohort Studies; D004558:Electric Stimulation; D004576:Electromyography; D019054:Evoked Potentials, Motor / Q000502:physiology; D005260:Female; D006614:Hindlimb / Q000294:innervation; D007537:Isometric Contraction / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology*; D059348:Peripheral Nerve Injuries / Q000473:pathology / Q000503:physiopathology; D010543:Peroneal Nerve / Q000502:physiology*; D051381:Rats; D011917:Rats, Inbred Lew; D012026:Reflex, Stretch / Q000502:physiology*; D013223:Statistics as Topic; D019415:Torque
keywords: functional evaluation; isometric force; nerve injury; noninvasive; rat