title: Speed, not magnitude, of knee extensor torque production is associated with self-reported knee function early after anterior cruciate ligament reconstruction.
abstract: OBJECTIVE
  To examine the magnitude and speed of knee extensor torque production at the initiation of advanced anterior cruciate ligament (ACL) reconstruction rehabilitation and the associations with self-reported knee function.
  
  
  METHODS
  Twenty-eight subjects who were 12 weeks post-ACL reconstruction and 28 age- and sex-matched physically active controls participated in this study. Knee extensor torque was assessed bilaterally with an isokinetic dynamometer at 60°/s. The variables of interest were peak torque, average rate of torque development, time to peak torque and quadriceps symmetry index. Knee function was assessed with the International Knee Documentation Committee Subjective Knee Form (IKDC-SKF).
  
  
  RESULTS
  Peak torque and average rate of torque development were lower on the surgical side compared to the non-surgical side and controls. Quadriceps symmetry index was lower in subjects with ACL reconstruction compared to controls. On the surgical side, average rate of torque development was positively correlated with IKDC-SKF score (r = 0.379) while time to peak torque was negatively correlated with IKDC-SKF score (r = -0.407).
  
  
  CONCLUSIONS
  At the initiation of advanced ACL reconstruction rehabilitation, the surgical side displayed deficits in peak torque and average rate of torque development. A higher rate of torque development and shorter time to peak torque were associated with better self-reported knee function. The results suggest that the rate of torque development should be addressed during advanced ACL reconstruction rehabilitation and faster knee extensor torque generation may lead to better knee function.
  
  
  METHODS
  III.
authors.affiliation: Department of Physical Therapy, University of Florida, Gainesville, FL, USA. chaojung@phhp.ufl.edu.
authors.forename: Chao-Jung
authors.initials: CJ
authors.lastname: Hsieh
authors.affiliation: Department of Orthopaedics and Rehabiltiation, University of Florida, Gainesville, FL, USA.
authors.forename: Peter A
authors.initials: PA
authors.lastname: Indelicato
authors.affiliation: Department of Orthopaedics and Rehabiltiation, University of Florida, Gainesville, FL, USA.
authors.forename: Michael W
authors.initials: MW
authors.lastname: Moser
authors.affiliation: Department of Physical Therapy, University of Florida, Gainesville, FL, USA.
authors.forename: Krista
authors.initials: K
authors.lastname: Vandenborne
authors.affiliation: Department of Physical Therapy, University of Florida, Gainesville, FL, USA. tchm@phhp.ufl.edu.
authors.forename: Terese L
authors.initials: TL
authors.lastname: Chmielewski
mesh_terms: D000328:Adult; D059549:Anterior Cruciate Ligament Reconstruction / Q000534:rehabilitation*; D005260:Female; D006801:Humans; D007719:Knee Joint / Q000502:physiology* / Q000601:surgery; D008297:Male; D053580:Muscle Strength / Q000502:physiology*; D053581:Muscle Strength Dynamometer; D057566:Self Report; D019415:Torque; D055815:Young Adult
keywords: Anterior cruciate ligament reconstruction; Isokinetic; Quadriceps strength; Rehabilitation outcomes