title: Relationships between Muscle Architecture of Rectus Femoris and Functional Parameters of Knee Motion in Adults with Down Syndrome.
abstract: This study was designed to measurein vivomuscle architecture of the rectus femoris in adults with Down syndrome, testing possible relationships with functional parameters of the knee motion. Ten adults with Down syndrome and ten typically developed participated in the study. Pennation angle and thickness of the rectus femoris and subcutaneous layer of the thigh were measured via ultrasound imaging. Knee kinematics and electromyographic activity of the rectus femoris were recorded during free leg dropping. Muscle thickness was reduced and subcutaneous layer was thicker in persons with Down syndrome with respect to typically developed adults, but there were no differences in the pennation angle. The area of the rectus femoris EMG activity during the leg flexion was greater in Down syndrome with respect to typically developed adults. The leg movement velocity was lower in Down people than in controls, but the knee excursion was similar between the groups. Functional parameters correlated with pennation angle in the persons with Down syndrome and with muscle thickness in typically developed persons. The description of muscle architecture and the relationships between morphological and functional parameters may provide insights on the limits and the opportunities to overcome the inherent biomechanical instability in Down syndrome.
authors.affiliation: Gait and Posture Motion Analysis Laboratory, Department of Biomedical and Biotechnological Sciences, University of Catania, 95125 Catania, Italy.
authors.forename: Maria Stella
authors.identifier: 0000-0001-9728-3542
authors.initials: MS
authors.lastname: Valle
authors.affiliation: Gait and Posture Motion Analysis Laboratory, Department of Biomedical and Biotechnological Sciences, University of Catania, 95125 Catania, Italy; Physical Medicine and Rehabilitation Residency Program, Department of Biomedical and Biotechnological Sciences, University of Catania, 95125 Catania, Italy.
authors.forename: Antonino
authors.identifier: 0000-0003-0180-4695
authors.initials: A
authors.lastname: Casabona
authors.affiliation: Gait and Posture Motion Analysis Laboratory, Department of Biomedical and Biotechnological Sciences, University of Catania, 95125 Catania, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Micale
authors.affiliation: Gait and Posture Motion Analysis Laboratory, Department of Biomedical and Biotechnological Sciences, University of Catania, 95125 Catania, Italy; Physical Medicine and Rehabilitation Residency Program, Department of Biomedical and Biotechnological Sciences, University of Catania, 95125 Catania, Italy.
authors.forename: Matteo
authors.initials: M
authors.lastname: Cioni
mesh_terms: D000328:Adult; D004314:Down Syndrome / Q000473:pathology / Q000503:physiopathology; D005260:Female; D006801:Humans; D007717:Knee / Q000473:pathology / Q000503:physiopathology; D008297:Male; D009068:Movement; D052097:Quadriceps Muscle / Q000473:pathology / Q000503:physiopathology