title: Biomechanical analysis of low back load when sneezing.
abstract: BACKGROUND
  Although sneezing is known to induce low back pain, there is no objective data of the load generated when sneezing. Moreover, the approaches often recommended for reducing low back pain, such as leaning with both hands against a wall, are not supported by objective evidence.
  
  
  METHODS
  Participants were 12 healthy young men (mean age 23.25 ± 1.54 years) with no history of spinal column pain or low back pain. Measurements were taken using a three-dimensional motion capture system and surface electromyograms in three experimental conditions: normal for sneezing, characterized by forward trunk inclination; stand, in which the body was deliberately maintained in an upright posture when sneezing; and table, in which the participants leaned with both hands on a table when sneezing. We analyzed and compared the intervertebral disk compressive force, low back moment, ground reaction force, trunk inclination angle, and co-contraction of the rectus abdominis and erector spinae muscles in the three conditions.
  
  
  RESULTS
  The intervertebral disk compressive force and ground reaction force were significantly lower in the stand and table conditions than in the normal condition. The co-contraction index value was significantly higher in the stand condition than in the normal and table conditions.
  
  
  CONCLUSIONS
  When sneezing, body posture in the stand or table condition can reduce load on the low back compared with body posture in the normal sneezing condition. Thus, placing both hands on a table or otherwise maintaining an upright body posture appears to be beneficial for reducing low back load when sneezing.
authors.affiliation: Graduate School, International University of Health and Welfare, 2600-1 Kitakanemaru, Otawara, Tochigi 324-8501, Japan. Electronic address: hasegawatetsuya1986@gmail.com.
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Hasegawa
authors.affiliation: Department of Odawara Health Science, International University of Health and Welfare, 1-2-25 Shiroyama, Odawara, Kanagawa 250-8588, Japan.
authors.forename: Junji
authors.initials: J
authors.lastname: Katsuhira
authors.affiliation: Department of Medical research and Management for Musculoskeletal pain,22nd Century Medical and Research Center, The University of Tokyo,7-3-1,Hongo,Bunkyo-ku,Tokyo,113-8655, Japan.
authors.forename: Ko
authors.initials: K
authors.lastname: Matsudaira
authors.affiliation: National Institute of Occupational Safety and Health, Nagao 6-21-1, Tama-ku, Kawasaki, Kanagawa 214-8585, Japan.
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Iwakiri
authors.affiliation: Department of Odawara Health Science, International University of Health and Welfare, 1-2-25 Shiroyama, Odawara, Kanagawa 250-8588, Japan.
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Maruyama
mesh_terms: D001415:Back / Q000502:physiology*; D004576:Electromyography; D006801:Humans; D017116:Low Back Pain / Q000209:etiology / Q000517:prevention & control; D008297:Male; D009119:Muscle Contraction / Q000502:physiology; D011187:Posture / Q000502:physiology; D012912:Sneezing / Q000502:physiology*; D013131:Spine / Q000502:physiology; D055815:Young Adult
keywords: Intervertebral disk compressive force; Low back load; Low back moment; Low back pain; Sneeze