title: Reducing anterior tibial translation by applying functional electrical stimulation in dynamic knee extension exercises: quantitative results acquired via marker tracking.
abstract: BACKGROUND
  Pain that accompanies anterior cruciate ligament deficiency during dynamic knee extension exercises is usually caused by excessive anterior tibial translation, which can be restricted if the anterior cruciate ligament was intact.
  
  
  METHODS
  A functional electrical stimulator is incorporated with a training device to induce hamstring contractions during certain degrees of knee extension to replicate effects similar to those generated by an intact anterior cruciate ligament and to reduce anterior tibial translation. By using a camera that tracks markers placed on bony prominences of the femur and tibia, the anterior tibial translations corresponding to various settings were determined by customized image processing procedures.
  
  
  RESULTS
  In the electrical stimulation sessions, the knee extensions with electrical stimulation feedback induced significantly (n=6, P<.05) less anterior tibial translation over the range of 20 to 50° when compared to those using the standard isokinetic shank restraint. Likewise, the knee extensions with an anti-shear device that blocks tibia displacement mechanically also induced significantly (n=6, P<.05) less anterior tibial translation, but over a different range of knee extension (30 to 70°).
  
  
  CONCLUSIONS
  Despite the fact that both the electrical stimulator and the anti-shear device assisted in reducing anterior tibial translation, the tendency of the curves generated with the functional electrical stimulation was generally more similar to those generated when using the standard isokinetic shank restraint.
authors.affiliation: Department of Electrical Engineering, National Taiwan University, Taiwan.
authors.forename: Chiun-Fan
authors.initials: CF
authors.lastname: Chen
authors.forename: Yi-Hsuan
authors.initials: YH
authors.lastname: Kuo
authors.forename: Jer-Junn
authors.initials: JJ
authors.lastname: Luh
authors.forename: Yu-Jen
authors.initials: YJ
authors.lastname: Chen
authors.forename: Shih-Wei
authors.initials: SW
authors.lastname: Chen
authors.forename: Te-Son
authors.initials: TS
authors.lastname: Kuo
authors.forename: Jin-Shin
authors.initials: JS
authors.lastname: Lai
mesh_terms: D000328:Adult; D016118:Anterior Cruciate Ligament / Q000502:physiology* / Q000503:physiopathology; D018771:Arthralgia / Q000503:physiopathology* / Q000534:rehabilitation; D004558:Electric Stimulation; D015444:Exercise / Q000502:physiology; D064368:Healthy Volunteers; D006801:Humans; D007719:Knee Joint / Q000502:physiology* / Q000503:physiopathology; D008297:Male; D009068:Movement / Q000502:physiology; D016059:Range of Motion, Articular; D013977:Tibia / Q000502:physiology*; D055815:Young Adult