title: Stabilometric response during single-leg stance after lower limb muscle fatigue.
abstract: OBJECTIVE
  This study sought to analyze the effect of muscle fatigue induced by active isotonic resistance training at a moderate intensity by measuring the knee extension motion during the stabilometric response in a single-leg stance among healthy university students who perform resistance training on a regular basis.
  
  
  METHODS
  Eleven healthy university students were subjected to a one-repetition maximum (1RM) test. In addition, stabilometric assessment was performed before and after the intervention and consisted of a muscle fatiguing protocol, in which knee extension was selected as the fatiguing task. The Shapiro-Wilk test was used to investigate the normality of the data, and the Wilcoxon test was used to compare the stabilometric parameters before and after induction of muscle fatigue, at a significance level of p≤0.05. Descriptive statistics were used in the analysis of the volunteers' age, height, body mass, and body mass index (BMI).
  
  
  RESULTS
  The sample population was 23.1±2.7 years of age, averaged 1.79.2±0.07 m in height and 75.6±8.0 Kg in weight, and had a BMI of 23.27±3.71 Kg.m-2. The volunteers performed exercises 3.36±1.12 days/week and achieved a load of 124.54±22.07 Kg on 1RM and 74.72±13.24 Kg on 60% 1RM. The center of pressure (CoP) oscillation on the mediolateral plane before and after fatigue induction was 2.89±0.89 mm and 4.09±0.59 mm, respectively, while the corresponding values on the anteroposterior plane were 2.5±2.2 mm and 4.09±2.26 mm, respectively. The CoP oscillation amplitude on the anteroposterior and mediolateral planes exhibited a significant difference before and after fatigue induction (p=0.04 and p=0.05, respectively).
  
  
  CONCLUSIONS
  The present study showed that muscle fatigue affects postural control, particularly with the mediolateral and anteroposterior CoP excursion.
authors.affiliation: Universidade Estadual de Londrina, LondrinaPRBrasil.
authors.forename: Carlos A V
authors.initials: CA
authors.lastname: Bruniera
authors.forename: Fernando R P G
authors.initials: FR
authors.lastname: Rogério
authors.forename: André L F
authors.initials: AL
authors.lastname: Rodacki
mesh_terms: D006801:Humans; D007866:Leg / Q000502:physiology*; D008297:Male; D018763:Muscle Fatigue / Q000502:physiology*; D004856:Postural Balance / Q000502:physiology*; D055070:Resistance Training; D055815:Young Adult