title: Knee flexor strength and endurance profiles after ipsilateral hamstring tendons anterior cruciate ligament reconstruction.
abstract: OBJECTIVE
  To profile knee flexor strength and endurance responses to ipsilateral hamstring tendon autograft anterior cruciate ligament reconstruction in patients, and to describe knee flexor strength and endurance as predictors of subjective outcomes. The hypothesis was that the involved leg would demonstrate deficits compared with uninvolved and matched legs.
  
  
  METHODS
  Retrospective cohort.
  
  
  METHODS
  Controlled laboratory.
  
  
  METHODS
  Women (n=15; mean age, 20.47±1.96y; height, 1.69±.08m; weight, 68.51±12.64kg), who were a mean ± SD of 25.93±11.25 months postsurgery, were matched to 15 sex-matched controls (mean age, 20.93±1.22y; height, 1.65±.06m; weight, 66.52±10.69kg).
  
  
  METHODS
  Not applicable.
  
  
  METHODS
  Concentric peak flexor moment over the entire isokinetic joint range of motion, peak flexor moment at 105° of joint flexion, and knee flexor total work, normalized to body mass, and subjective questionnaire scores for the involved leg.
  
  
  RESULTS
  Significantly lesser peak flexor moment over the entire isokinetic joint range of motion (P=.034) and total work (P=.048) existed for the involved leg (.959±.186Nm/kg; 21.933±5.881J/kg) compared with the matched leg (1.108±.134Nm/kg; 27.431±6.499J/kg). Significantly lesser peak flexor moment at 105° of joint flexion (P=.002) existed between the involved (.221±.116Nm/kg) and uninvolved (.40±.234Nm/kg) and matched (.475±.183Nm/kg) legs. Significantly greater strength deficits (P≤.001) existed at peak flexor moment at 105° of joint flexion compared with peak flexor moment over the entire isokinetic joint range of motion for side (53.83%±38.8%; 9.87%±10.77%) and group (77.61%±44.14%; 18.09%±11.73%) differences. Peak flexor moment at 105° of joint flexion was a significant predictor of subjective pain (P=.007), symptoms (P=.006), function (P=.011), and sports (P=.022) outcomes.
  
  
  CONCLUSIONS
  Knee flexor strength and endurance deficits suggest susceptibility to reinjury, and strength in a deep joint angle predicts subjective outcomes.
authors.affiliation: Athletic Training and Sports Medicine Research Laboratory, Department of Kinesiology, College of Health and Human Development, The Pennsylvania State University, University Park, PA; Sports Medicine Clinical Research Agenda, Penn State Hershey Bone and Joint Institute - State College, State College, PA. Electronic address: glv103@psu.edu.
authors.forename: Giampietro L
authors.initials: GL
authors.lastname: Vairo
mesh_terms: D000328:Adult; D059549:Anterior Cruciate Ligament Reconstruction / Q000534:rehabilitation*; D015992:Body Mass Index; D005260:Female; D006801:Humans; D007717:Knee / Q000503:physiopathology*; D053580:Muscle Strength / Q000502:physiology*; D010807:Physical Endurance; D026741:Physical Therapy Modalities; D016059:Range of Motion, Articular; D012189:Retrospective Studies
keywords: Athletic performance; General surgery; Joints; Muscles; Rehabilitation