title: Structural and functional changes in spastic skeletal muscle.
abstract: This review summarizes current information regarding the changes in structure or function that occur in skeletal muscle secondary to spasticity. Most published studies have reported an increase in fiber size variability in spastic muscle. There is no general agreement regarding any shift in fiber type distribution secondary to spasticity. Mechanical studies in whole limbs as well as in isolated single cells support the notion of an intrinsic change in the passive mechanical properties of muscle after spasticity in addition to the more widely reported neural changes that occur. Evidence is presented for changes within both the muscle cell and extracellular matrix that contribute to the overall changes in the tissue. Taken together, the literature supports the notion that, although spasticity is multifactorial and neural in origin, significant structural alterations in muscle also occur. An understanding of the specific changes that occur in the muscle and extracellular matrix may facilitate the development of new conservative or surgical therapies for this problem.
authors.affiliation: Departments of Orthopaedic Surgery and Bioengineering, University of California and Veterans Administration Medical Centers, 3350 La Jolla Village Drive, San Diego, California 92161, USA. rlieber@ucsd.edu
authors.forename: Richard L
authors.initials: RL
authors.lastname: Lieber
authors.forename: Suzanne
authors.initials: S
authors.lastname: Steinman
authors.forename: Ilona A
authors.initials: IA
authors.lastname: Barash
authors.forename: Hank
authors.initials: H
authors.lastname: Chambers
mesh_terms: D000818:Animals; D006801:Humans; D009119:Muscle Contraction / Q000502:physiology; D018485:Muscle Fibers, Skeletal / Q000473:pathology / Q000502:physiology; D009128:Muscle Spasticity / Q000473:pathology* / Q000503:physiopathology*; D018482:Muscle, Skeletal / Q000473:pathology* / Q000503:physiopathology*