Knee extension torque variability after exercise in ACL reconstructed knees

John Goetschius, Christopher M. Kuenze, Joseph M. Hart

Research output: Contribution to journalArticlepeer-review

14 Scopus citations


The purpose of this study was to compare knee extension torque variability in patients with ACL reconstructed knees before and after exercise. Thirty two patients with an ACL reconstructed knee (ACL-R group) and 32 healthy controls (control group) completed measures of maximal isometric knee extension torque (90°flexion) at baseline and following a 30-min exercise protocol (post-exercise). Exercise included 30-min of repeated cycles of inclined treadmill walking and hopping tasks. Dependent variables were the coefficient of variation (CV) and raw-change in CV (ΔCV): CV=(torque standard deviation/torque meanx100), ΔCV=(post-exercise - baseline). There was a group-by-time interaction (p=0.03) on CV. The ACL-R group demonstrated greater CV than the control group at baseline (ACL-R=1.07±0.55, control=0.79±0.42, p=0.03) and post-exercise (ACL-R=1.60±0.91, control=0.94±0.41, p=0.001). ΔCV was greater (p=0.03) in the ACL-R group (0.52±0.82) than control group (0.15±0.46). CV significantly increased from baseline to post-exercise (p=0.001) in the ACL-R group, while the control group did not (p=0.06). The ACL-R group demonstrated greater knee extension torque variability than the control group. Exercise increased torque variability more in the ACL-R group than control group.

Original languageEnglish (US)
Pages (from-to)1165-1170
Number of pages6
JournalJournal of Orthopaedic Research
Issue number8
StatePublished - Aug 1 2015
Externally publishedYes


  • motor control
  • muscle fatigue
  • neuromuscular
  • quadriceps muscle
  • steadiness

ASJC Scopus subject areas

  • Orthopedics and Sports Medicine


Dive into the research topics of 'Knee extension torque variability after exercise in ACL reconstructed knees'. Together they form a unique fingerprint.

Cite this