title: Muscle lengthening surgery causes differential acute mechanical effects in both targeted and non-targeted synergistic muscles.
abstract: Epimuscular myofascial force transmission (EMFT) is a major determinant of muscle force exerted, as well as length range of force exertion. Therefore, EMFT is of importance in remedial surgery performed, e.g., in spastic paresis. We aimed to test the following hypotheses: (1) muscle lengthening surgery (involving preparatory dissection (PD) and subsequent proximal aponeurotomy (AT)) affects the target muscle force exerted at its distal and proximal tendons differentially, (2) forces of non-operated synergistic muscles are affected as well, (3) PD causes some of these effects. In three conditions (control, post-PD, and post-AT exclusively on m. extensor digitorum longus (EDL)), forces exerted by rat anterior crural muscles were measured simultaneously. Our results confirm hypotheses (1-2), and hypothesis (3) in part: Reduction of EDL maximal force differed by location (i.e. 26.3% when tested distally and 44.5% when tested proximally). EDL length range of active force exertion increased only distally. Force reductions were shown also for non-operated tibialis anterior (by 11.9%), as well as for extensor hallucis longus (by 8.4%) muscles. In tibialis anterior only, part of the force reduction (4.9%) is attributable to PD. Due to EMFT, remedial surgery should be considered to have differential effects for targeted and non-targeted synergistic muscles.
authors.affiliation: Biomedical Engineering Institute, Boğaziçi University, Istanbul, Turkey.
authors.forename: Filiz
authors.initials: F
authors.lastname: Ateş
authors.forename: Rana N
authors.initials: RN
authors.lastname: Özdeşlik
authors.forename: Peter A
authors.initials: PA
authors.lastname: Huijing
authors.forename: Can A
authors.initials: CA
authors.lastname: Yucesoy
mesh_terms: D000818:Animals; D003238:Connective Tissue / Q000502:physiology* / Q000601:surgery*; D008297:Male; D009119:Muscle Contraction / Q000502:physiology*; D053580:Muscle Strength / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology* / Q000601:surgery*; D019637:Orthopedic Procedures / Q000379:methods*; D004856:Postural Balance / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar
keywords: Aponeurotomy; Epimuscular myofascial force transmission; Muscle length-force characteristics; Muscle lengthening surgery; Rat anterior crural compartment