title: Intact muscle compartment exposed to botulinum toxin type A shows compromised intermuscular mechanical interaction.
abstract: BACKGROUND
  We tested the hypothesis that BTX-A diminishes epimuscular myofascial force transmission (EMFT) within an intact muscle compartment.
  
  
  METHODS
  The tibialis anterior (TA) and extensor hallucis longus (EHL) muscles were kept at constant length, whereas the position of the extensor digitorum longus (EDL) muscle was changed exclusively. Two groups of Wistar rats were tested: a control group (no BTX-A injected) and a BTX group (0.1 unit of BTX-A injected into the mid-belly of TA).
  
  
  RESULTS
  In controls, distally altered EDL position affected EDL distal and proximal forces and proximodistal force differences, indicating substantial EMFT. In the BTX group, EDL forces measured at the most proximal position did not change significantly with altered muscle position, and EDL proximodistal force differences became minimized.
  
  
  CONCLUSIONS
  Use of BTX-A diminishes EMFT. It may be relevant clinically that BTX-A compromises intermuscular mechanical interaction, as recent studies have shown that such an interaction plays a role in the abnormal mechanics of spastic muscle.
authors.affiliation: Biomedical Engineering Institute, BoğaziÇi University, 34684, Çengelköy Istanbul, Turkey.
authors.forename: Can A
authors.initials: CA
authors.lastname: Yucesoy
authors.forename: Ahu Nur
authors.initials: AN
authors.lastname: Turkoğlu
authors.forename: Sevgi
authors.initials: S
authors.lastname: Umur
authors.forename: Filiz
authors.initials: F
authors.lastname: Ateş
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D001696:Biomechanical Phenomena; D019274:Botulinum Toxins, Type A / Q000494:pharmacology*; D004558:Electric Stimulation; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects*; D018482:Muscle, Skeletal / Q000187:drug effects*; D009465:Neuromuscular Agents / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D013314:Stress, Mechanical
chemical_list: D009465:Neuromuscular Agents; D019274:Botulinum Toxins, Type A
keywords: botulinum toxin type A; epimuscular myofascial force transmission; intermuscular mechanical interaction; multi-articular muscle; muscle relative position