title: Motor control of the lower extremity musculature in children with cerebral palsy.
abstract: The aim of this investigation was to quantify the differences in torque steadiness and variability of the muscular control in children with cerebral palsy (CP) and typically developing (TD) children. Fifteen children with CP (age=14.2±0.7 years) that had a Gross Motor Function Classification System (GMFCS) score of I-III and 15 age and gender matched TD children (age=14.1±0.7 years) participated in this investigation. The participants performed submaximal steady-state isometric contractions with the ankle, knee, and hip while surface electromyography (sEMG) was recorded. An isokinetic dynamometer was used to measure the steady-state isometric torques while the participants matched a target torque of 20% of the subject's maximum voluntary torque value. The coefficient of variation was used to assess the amount of variability in the steady-state torque, while approximate entropy was used to assess the regularity of the steady-state torque over time. Lastly, the distribution of the power spectrum of the respective sEMG was evaluated. The results of this investigation were: 1) children with CP had a greater amount of variability in their torque steadiness at the ankle than TD children, 2) children with CP had a greater amount of variability at the ankle joint than at the knee and hip joint, 3) the children with CP had a more regular steady-state torque pattern than TD children for all the joints, 4) the ankle sEMG of children with CP was composed of higher harmonics than that of the TD children.
authors: Department of Physical Therapy, Munroe-Meyer Institute for Genetics and Rehabilitation, University of Nebraska Medical Center, Omaha, NE, United States.
authors: David J
authors: DJ
authors: Arpin
authors: Wayne
authors: W
authors: Stuberg
authors: Nicholas
authors: N
authors: Stergiou
authors: Max J
authors: MJ
authors: Kurz
mesh_terms: D000293:Adolescent; D000843:Ankle Joint / Q000503:physiopathology; D016022:Case-Control Studies; D002547:Cerebral Palsy / Q000503:physiopathology; D002648:Child; D004576:Electromyography; D005260:Female; D006621:Hip Joint / Q000503:physiopathology; D006801:Humans; D007537:Isometric Contraction / Q000502:physiology*; D007719:Knee Joint / Q000503:physiopathology; D035002:Lower Extremity / Q000503:physiopathology; D008297:Male; D018482:Muscle, Skeletal / Q000503:physiopathology*; D019415:Torque