title: Multiple sclerosis and postural control: the role of spasticity.
abstract: Sosnoff JJ, Shin S, Motl RW. Multiple sclerosis and postural control: the role of spasticity.
  
  
  OBJECTIVE
  To examine the association between spasticity and postural control in subjects with multiple sclerosis (MS).
  
  
  METHODS
  Cross-sectional.
  
  
  METHODS
  Motor control laboratory.
  
  
  METHODS
  Subjects with MS (n=16, 2 male) and age and sex-matched subjects (n=16) participated in the investigation. All subjects with MS had Expanded Disability Status Scale scores between 0 and 4.5 and modified Ashworth scale scores between 1 and 3.
  
  
  METHODS
  Not applicable.
  
  
  METHODS
  Postural control was measured with a force platform that quantifies ground reaction forces and moments in mediolateral and anteroposterior directions. Postural control was indexed with anterior-posterior sway range, medial-lateral sway range, 95% elliptical area of the deviations of center of pressure (COP), velocity of COP sway, and the frequency at which 95% of spectral profile was contained. Participants with MS further underwent assessment of the soleus Hoffman reflex (H-reflex) as an index of spasticity.
  
  
  RESULTS
  Cluster analysis on H-reflex data identified groups of MS participants with high spasticity (n=7) and low spasticity (n=9). There were no differences in age, duration of MS, and disease severity between MS groups. There were no differences in anterior-posterior sway range between any of the groups. The high spasticity group had greater COP area, velocity, and mediolateral sway compared with the low spasticity and control group, and the low spasticity group had postural control values between the high spasticity and control groups.
  
  
  CONCLUSIONS
  The pattern of results suggests that spasticity contributes to postural deficits observed in MS.
authors.affiliation: Department of Kinesiology and Community Health, University of Illinois at Urbana-Champaign, Urbana, IL, USA. jsosnoff@uiuc.edu
authors.forename: Jacob J
authors.initials: JJ
authors.lastname: Sosnoff
authors.forename: Sunghoon
authors.initials: S
authors.lastname: Shin
authors.forename: Robert W
authors.initials: RW
authors.lastname: Motl
mesh_terms: D000328:Adult; D016000:Cluster Analysis; D003430:Cross-Sectional Studies; D005260:Female; D006181:H-Reflex; D006801:Humans; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000503:physiopathology* / Q000534:rehabilitation; D009128:Muscle Spasticity / Q000503:physiopathology*; D018482:Muscle, Skeletal / Q000503:physiopathology*; D004856:Postural Balance / Q000502:physiology*