title: Weightbath hydrotraction treatment: application, biomechanics, and clinical effects.
abstract: OBJECTIVE
  Weightbath hydrotraction treatment (WHT) is a simple noninvasive effective method of hydro- or balneotherapy to stretch the spine or lower limbs, applied successfully in hospitals and health resort sanitaria in Hungary for more than fifty years. This study aims to introduce WHT with its biomechanical and clinical effects. History, development, equipment, modes of application, biomechanics, spinal traction forces and elongations, indications and contraindications of WHT are precented.
  
  
  METHODS
  The calculation of traction forces acting along the spinal column during the treatment is described together with the mode of suspension and the position of extra weight loads applied. The biomechanics of the treatment are completed by in vivo measured elongations of lumbar segments using a special underwater ultrasound measuring method. The clinical effects, indications, and contraindications of the treatment are also presented.
  
  
  RESULTS
  In the underwater cervical suspension of a human body, approximately 25 N stretching load occurs in the cervical spine, and about 11 N occurs in the lumbar spine. By applying extra weights, the above tensile forces along the spinal column can be increased. Thus, the traction effect can be controlled by applying such loads during the treatment. Elongations of segments L3-L4, L4-L5, and L5-S1 were measured during the usual WHT of patients suspended cervically in water for 20 minutes, loaded by 20-20 N lead weights on the ankles. The mean initial elastic elongations of spinal segments were about 0.8 mm for patients aged under 40 years, 0.5 mm between 40-60 years, and 0.2 mm for patients over 60 years. The mean final viscoelastic elongations were 1.5 mm, 1.2 mm, and 0.6 mm for the same age classes, respectively. No significant difference was found between the sexes regarding age-dependence in tension. WHT for discopathy showed significant improvement of clinical parameters, which was still evident three months later, as demonstrated by using a controlled pilot study.
  
  
  CONCLUSIONS
  WHT effectively mitigates pain, enhances joint flexibility, and improves the quality of life of patients. The WHT equipment is easy to install and the treatment technique is simple. The authors are the first to determine the biomechanical effects of WHT using an in vivo-measuring method and biomechanical calculations; and verifying the beneficial clinical effects by a controlled pilot study. Approximate values of tensile forces occurring along different points of the spinal column have been calculated, depending on the mode of the suspension, and the value and position of the applied extra weight loads. Time-related viscoelastic elongations of lumbar segments and discs have been measured in vivo, in terms of sex, age, body weight and height and the position of the segment. Several clinical parameters were analyzed by a controlled pilot study to verify the beneficial effects of WHT for cervical and lumbar discopathy. Based on these results, advice can be given to therapists to obtain the optimal traction effects of the treatment.
authors.affiliation: Department of Structural Mechanics, Budapest University of Technology and Economics, Hungary;
authors.forename: Márta
authors.initials: M
authors.lastname: Kurutz
authors.forename: Tamás
authors.initials: T
authors.lastname: Bender