title: Perception of Muscular Effort During Dynamic Elbow Extension in Multiple Sclerosis.
abstract: OBJECTIVE
  To investigate the perception of muscular effort in individuals with multiple sclerosis (MS) and healthy controls during dynamic contractions.
  
  
  METHODS
  Case-control study.
  
  
  METHODS
  MS day care center.
  
  
  METHODS
  Individuals with MS (n=28) and controls (n=28) (N=56).
  
  
  METHODS
  Not applicable.
  
  
  METHODS
  Perceived muscular effort during dynamic elbow extensions was rated at 9 different weight intensities (10%-90% of 1-repetition maximum) in a single-blind, randomized order using the OMNI-Resistance Exercise Scale. Muscle activity of the triceps brachii muscle (lateral head) was measured via surface electromyography and normalized to maximal voluntary excitation.
  
  
  RESULTS
  According to OMNI-level ratings, significant main effects were found for the diagnostic condition (F=27.33, P<.001, η(2)=.11), indicating 0.7 (95% confidence interval [CI], 0.3-1.1) lower mean OMNI-level ratings for MS, and for the intensity level (F=46.81, P<.001, η(2)=.46), showing increased OMNI-level ratings for increased intensity levels for both groups. Furthermore, significant main effects were found for the diagnostic condition (F=16.52, P<.001, η(2)=.07), indicating 7.1% (95% CI, -8.6 to 22.8) higher maximal voluntary excitation values for MS, and for the intensity level (F=33.09, P<.001, η(2)=.36), showing higher relative muscle activities for increasing intensity levels in both groups.
  
  
  CONCLUSIONS
  Similar to controls, individuals with MS were able to differentiate between different intensities of weight during dynamic elbow extensions when provided in a single-blind, randomized order. Therefore, perceived muscular effort might be considered to control resistance training intensities in individuals with MS. However, training intensity for individuals with MS should be chosen at approximately 1 OMNI level lower than recommended, at least for dynamic elbow extension exercises.
authors.affiliation: Department of Biomechanics, Kinesiology and Applied Computer Science, Center for Sport Science and University Sports, University of Vienna, Vienna, Austria. Electronic address: mario.heller@univie.ac.at.
authors.forename: Mario
authors.initials: M
authors.lastname: Heller
authors.affiliation: Department for Clinical Neurosciences and Preventive Medicine, Faculty of Health and Medicine, Danube University Krems, Krems, Austria.
authors.forename: Irene
authors.initials: I
authors.lastname: Retzl
authors.affiliation: Day Care Center for Multiple Sclerosis, Caritas Socialis, Vienna, Austria; Department of Physiotherapy, St. Poelten University of Applied Sciences, St. Poelten, Austria.
authors.forename: Anita
authors.initials: A
authors.lastname: Kiselka
authors.affiliation: Department of Physical Therapy, University of Applied Sciences Fachhochschule Campus Vienna, Vienna, Austria.
authors.forename: Andrea
authors.initials: A
authors.lastname: Greisberger
mesh_terms: D016022:Case-Control Studies; D004551:Elbow Joint / Q000502:physiology*; D004576:Electromyography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000503:physiopathology*; D009119:Muscle Contraction / Q000502:physiology; D005082:Physical Exertion / Q000502:physiology*; D016037:Single-Blind Method; D014891:Weight Lifting / Q000502:physiology*
keywords: Electromyography; Multiple sclerosis; Muscle contraction; Rehabilitation; Upper extremity; Weight perception