Motor physical therapy affects muscle collagen type I and decreases gait speed in dystrophin-deficient dogs.
Golden Retriever Muscular Dystrophy (GRMD) is a dystrophin-deficient canine model genetically homologous to Duchenne Muscular Dystrophy (DMD) in humans. Muscular fibrosis secondary to cycles of degeneration/regeneration of dystrophic muscle tissue and muscular weakness leads to biomechanical adaptation that impairs the quality of gait. Physical therapy (PT) is one of the supportive therapies available for DMD, however, motor PT approaches have controversial recommendations and there is no consensus regarding the type and intensity of physical therapy. In this study we investigated the effect of physical therapy on gait biomechanics and muscular collagen deposition types I and III in dystrophin-deficient dogs. Two dystrophic dogs (treated dogs-TD) underwent a PT protocol of active walking exercise, 3×/week, 40 minutes/day, 12 weeks. Two dystrophic control dogs (CD) maintained their routine of activities of daily living. At t0 (pre) and t1 (post-physical therapy), collagen type I and III were assessed by immunohistochemistry and gait biomechanics were analyzed. Angular displacement of shoulder, elbow, carpal, hip, stifle and tarsal joint and vertical (Fy), mediolateral (Fz) and craniocaudal (Fx) ground reaction forces (GRF) were assessed. Wilcoxon test was used to verify the difference of biomechanical variables between t0 and t1, considering p<.05. Type I collagen of endomysium suffered the influence of PT, as well as gait speed that had decreased from t0 to t1 (p<.000). The PT protocol employed accelerates morphological alterations on dystrophic muscle and promotes a slower velocity of gait. Control dogs which maintained their routine of activities of daily living seem to have found a better balance between movement and preservation of motor function.
Department of Physical Therapy, Faculty of Biological Science and Health, University of Jequitinhonha and Mucuri Valley/UFVJM, Diamantina/MG, Brazil.
Thaís P
TP
Gaiad
Department of Surgery, School of Veterinary Medicine and Animal Science, University of Sao Paulo/USP, São Paulo, SP, Brazil.
Karla P C
KP
Araujo
Department of Biodynamic, School of Physical Education and Sports, University of São Paulo/USP, São Paulo, Brazil.
Júlio C
JC
Serrão
Department of Surgery, School of Veterinary Medicine and Animal Science, University of Sao Paulo/USP, São Paulo, SP, Brazil.
Maria A
MA
Miglino
Department of Veterinary Medicine, School of Animal Sciences and Food Engineering, University of São Paulo/USP, Pirassununga, SP, Brazil.
Carlos Eduardo
CE
Ambrósio
D000818:Animals; D024042:Collagen Type I / Q000032:analysis* / Q000378:metabolism; D004195:Disease Models, Animal; D004285:Dogs; D005081:Exercise Therapy; D005684:Gait; D006801:Humans; D018482:Muscle, Skeletal / Q000473:pathology / Q000503:physiopathology*; D009137:Muscular Dystrophy, Animal / Q000473:pathology / Q000503:physiopathology / Q000628:therapy*; D020388:Muscular Dystrophy, Duchenne / Q000473:pathology / Q000503:physiopathology / Q000628:therapy*
D024042:Collagen Type I