title: Remobilization through stretching improves gait recovery in the rat.
abstract: Remobilization of a previously immobilized rat right hindlimb in the ankle plantar-flexion-shortened position by free movement alone or associated with intermittent passive stretching was assessed by analysis of gait variables and dorsiflexion range of motion. The variables were related with the expression of extracellular matrix proteins and the addition of serial sarcomeres. Sixty-four female Wistar rats were divided into 8 groups: immobilized, free for 10 days, immobilized/stretched/free for 1, 3 or 10 days, immobilized/free for 1, 3 or 10 days. Gait variables, range of motion, serial sarcomeres number, localization and staining intensity of fibronectin, and expressions of types I and III collagen were analyzed. The hypokinesia changed the functional variables of gait, reduced the dorsiflexion range of motion (ROM), increased the number of fibers with intracellular fibronectin/total number of fibers (FIF/TNF), and decreased the expression of the type I collagen. After three days, morphological changes were exacerbated and the number of serial sarcomeres was increased in both groups, immobilized/stretched/free and immobilized/free. Functional impairment, ROM restriction and increased FIF/TNF were also observed. Despite the above described alterations, 10 days of stretching program increased the effectiveness of remobilization leading to recovery of the abnormalities observed in the muscle.
authors.affiliation: Department of Biomechanics, Medicine, and Rehabilitation of the Locomotor Apparatus, Ribeirão Preto School of Medicine, University of São Paulo, São Paulo, Brazil.
authors.forename: Letícia Oliveira
authors.initials: LO
authors.lastname: Cação-Benedini
authors.forename: Paula Guilherme
authors.initials: PG
authors.lastname: Ribeiro
authors.forename: Anna Raquel Silveira
authors.initials: AR
authors.lastname: Gomes
authors.forename: Julye Leiko
authors.initials: JL
authors.lastname: Ywazaki
authors.forename: Vanessa Vilela
authors.initials: VV
authors.lastname: Monte-Raso
authors.forename: Cibele Maria
authors.initials: CM
authors.lastname: Prado
authors.forename: Ana Claudia
authors.initials: AC
authors.lastname: Mattiello-Sverzut
mesh_terms: D000818:Animals; D003094:Collagen / Q000378:metabolism; D005109:Extracellular Matrix / Q000378:metabolism / Q000648:ultrastructure; D005260:Female; D005353:Fibronectins / Q000378:metabolism; D019417:Hindlimb Suspension; D052580:Muscle Stretching Exercises / Q000379:methods*; D018482:Muscle, Skeletal / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology; D010805:Physical Conditioning, Animal; D016059:Range of Motion, Articular / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D020127:Recovery of Function; D012518:Sarcomeres / Q000378:metabolism / Q000648:ultrastructure; D013264:Stifle / Q000503:physiopathology
chemical_list: D005353:Fibronectins; D003094:Collagen