title: Examining neuromuscular control during landings on a supinating platform in persons with and without ankle instability.
abstract: BACKGROUND
  Ankle instability is a costly public health concern because of the associated recurrent sprains. It is evident there are neuromuscular control deficits predisposing these individuals to their ankle "giving way." Individuals with a history of lateral ankle sprain, who did not develop instability, may hold the key to understanding proper neuromuscular control after injury.
  
  
  OBJECTIVE
  On the basis of previous research, the authors hypothesized that individuals with ankle instability would demonstrate reduced peroneal activation, causing a more inverted position of the ankle, before and after landing.
  
  
  METHODS
  Controlled laboratory study.
  
  
  METHODS
  This study aimed to evaluate preparatory and reactive neuromuscular control when landing on a custom-designed ankle supinating device in individuals with ankle instability (AI), individuals with a history of lateral ankle sprains without instability (LAS), and uninjured controls (CON). Forty-five participants (15 per group) were asked to land on a device built to simulate the mechanism of a lateral ankle sprain (supination) while kinematics and muscle activity of the lower extremity were monitored.
  
  
  RESULTS
  Contrary to our hypotheses, the AI group displayed significantly increased preparatory (P = .01) and reactive (P = .02) peroneal activation, while the LAS group demonstrated a trend toward increased preparatory tibialis anterior muscle activation (P = .07), leading to a decreased plantar flexion of the ankle at landing.
  
  
  CONCLUSIONS
  The AI group was likely acting in a protective fashion to a potentially injurious situation, indicating these individuals can activate the peroneals if needed. The LAS group's strategy may be a safer strategy in that a less plantar-flexed position of the ankle is more close-packed and stable. Further, it appears the long-latency response of the peroneals may be enhanced in these individuals, which indicates motor learning at the supraspinal level to promote dynamic restraint.
  
  
  CONCLUSIONS
  Individuals with AI can increase peroneal activation when necessary to dynamically stabilize the ankle, indicating the potential for training/rehabilitation. Further, the LAS group may deploy a different control strategy after injury to protect the ankle from subsequent sprains, which deserves investigation during activities of daily living. A greater understanding of these strategies will lead to the development of more appropriate treatment paradigms after injury to minimize the incidence of instability.
authors.affiliation: Arthur J. Nelson, Jr Human Performance Laboratory, Department of Physical Therapy, New York University, New York, NY 10010, USA. gmgutierrez@gmail.com
authors.forename: Gregory M
authors.initials: GM
authors.lastname: Gutierrez
authors.forename: Christopher A
authors.initials: CA
authors.lastname: Knight
authors.forename: Charles B
authors.initials: CB
authors.lastname: Swanik
authors.forename: Todd
authors.initials: T
authors.lastname: Royer
authors.forename: Kurt
authors.initials: K
authors.lastname: Manal
authors.forename: Brian
authors.initials: B
authors.lastname: Caulfield
authors.forename: Thomas W
authors.initials: TW
authors.lastname: Kaminski
mesh_terms: D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D000843:Ankle Joint / Q000503:physiopathology*; D001696:Biomechanical Phenomena; D016022:Case-Control Studies; D004569:Electroencephalography; D005260:Female; D006801:Humans; D007593:Joint Instability / Q000503:physiopathology*; D008297:Male; D012984:Software; D013484:Supination; D011795:Surveys and Questionnaires