title: Obesity-related differences in neural correlates of force control.
abstract: BACKGROUND
  Greater body segment mass due to obesity has shown to impair gross and fine motor functions and reduce balance control. While recent studies suggest that obesity may be linked with altered brain functions involved in fine motor tasks, this association is not well investigated.
  
  
  OBJECTIVE
  The purpose of this study was to examine the neural correlates of motor performance in non-obese and obese adults during force control of two upper extremity muscles.
  
  
  METHODS
  Nine non-obese and eight obese young adults performed intermittent handgrip and elbow flexion exertions at 30% of their respective muscle strengths for 4 min. Functional near infrared spectroscopy was employed to measure neural activity in the prefrontal cortex bilaterally, joint steadiness was computed using force fluctuations, and ratings of perceived exertions (RPEs) were obtained to assess perceived effort.
  
  
  RESULTS
  Obesity was associated with higher force fluctuations and lower prefrontal cortex activation during handgrip exertions, while RPE scores remained similar across both groups. No obesity-related differences in neural activity, force fluctuation, or RPE scores were observed during elbow flexion exertions.
  
  
  CONCLUSIONS
  The study is one of the first to examine obesity-related differences on prefrontal cortex activation during force control of the upper extremity musculature. The study findings indicate that the neural correlates of motor activity in the obese may be muscle-specific. Future work is warranted to extend the investigation to monitoring multiple motor-function related cortical regions and examining obesity differences with different task parameters (e.g., longer duration, increased precision demands, larger muscles, etc.).
authors.affiliation: Department of Environmental and Occupational Health, Texas A&M University, College Station, TX, 77843, USA, rmehta@tamu.edu.
authors.forename: Ranjana K
authors.initials: RK
authors.lastname: Mehta
authors.forename: Ashley E
authors.initials: AE
authors.lastname: Shortz
mesh_terms: D016022:Case-Control Studies; D005260:Female; D018737:Hand Strength; D006801:Humans; D008297:Male; D009048:Motor Skills; D018482:Muscle, Skeletal / Q000294:innervation / Q000502:physiology*; D009765:Obesity / Q000503:physiopathology*; D017397:Prefrontal Cortex / Q000502:physiology*; D034941:Upper Extremity / Q000294:innervation / Q000502:physiology; D055815:Young Adult