Unloading reactions in functional ankle instability

Gait Posture. 2008 May;27(4):589-94. doi: 10.1016/j.gaitpost.2007.08.001. Epub 2007 Sep 21.


Past studies have suggested that unloading reactions may be a strategy to prevent ankle sprains. This study tested unloading reactions in individuals with functional ankle instability (FAI) in order to better understand this phenomenon. We provoked unloading reactions in 20 individuals with FAI and 18 healthy controls by delivering nociceptive electrical stimulation to the lateral aspect of the ankle during standing. Ground reaction forces, lower extremity kinematics, and EMG activity of five muscles of the lower limb were recorded. Individuals with FAI demonstrated increased and faster body weight unloading after stimulation. This hyper-reactivity may partially account for the sensation of the ankle "giving way" in those with a history of severe ankle sprain and subsequent functional instability.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Analysis of Variance
  • Ankle Joint / physiopathology*
  • Case-Control Studies
  • Electric Stimulation
  • Electromyography
  • Female
  • Humans
  • Joint Instability / physiopathology*
  • Leg / physiopathology
  • Male
  • Middle Aged
  • Pain Threshold
  • Reaction Time / physiology*
  • Sprains and Strains / physiopathology*