title: Could martial arts fall training be safe for persons with osteoporosis?: a feasibility study.
abstract: BACKGROUND
  Osteoporosis is a well-established risk factor for fall-related hip fractures. Training fall arrest strategies, such as martial arts (MA) fall techniques, might be useful to prevent hip fractures in persons with osteoporosis, provided that the training itself is safe. This study was conducted to determine whether MA fall training would be safe for persons with osteoporosis extrapolated from the data of young adults and using stringent safety criteria.
  
  
  METHODS
  Young adults performed sideways and forward MA falls from a kneeling position on both a judo mat and a mattress as well as from a standing position on a mattress. Hip impact forces and kinematic data were collected. For each condition, the highest hip impact force was compared with two safety criteria based on the femoral fracture load and the use of a hip protector.
  
  
  RESULTS
  The highest hip impact force during the various fall conditions ranged between 1426 N and 3132 N. Sideways falls from a kneeling and standing position met the safety criteria if performed on the mattress (max 1426 N and 2012 N, respectively) but not if the falls from a kneeling position were performed on the judo mat (max 2219 N). Forward falls only met the safety criteria if performed from a kneeling position on the mattress (max 2006 N). Hence, forward falls from kneeling position on a judo mat (max 2474 N) and forward falls from standing position on the mattress (max 3132 N) did not meet both safety criteria.
  
  
  CONCLUSIONS
  Based on the data of young adults and safety criteria, the MA fall training was expected to be safe for persons with osteoporosis if appropriate safety measures are taken: during the training persons with osteoporosis should wear hip protectors that could attenuate the maximum hip impact force by at least 65%, perform the fall exercises on a thick mattress, and avoid forward fall exercises from a standing position. Hence, a modified MA fall training might be useful to reduce hip fracture risk in persons with osteoporosis.
authors.affiliation: Sint Maartenskliniek Research, Development and Education, Hengstdal 3, 6522 JV Nijmegen, the Netherlands. b.groen@maartenskliniek.nl.
authors.forename: Brenda E
authors.initials: BE
authors.lastname: Groen
authors.forename: Ellen
authors.initials: E
authors.lastname: Smulders
authors.forename: Jacques
authors.initials: J
authors.lastname: Duysens
authors.forename: Wim
authors.initials: W
authors.lastname: van Lankveld
authors.forename: Vivian
authors.initials: V
authors.lastname: Weerdesteyn