Poster Presentations/Osteoarthritis and Cartilage 19S1 (2011) S53–S236 S91 Methods: Twelve subjects with a traumatic-onset meniscal tear were recruited for this study (11 males; mean age: 19.5±3.0 yrs; 10 lateral tears/2 medial tears). Testing consisted of gait analysis and questionnaires. Retro-reflective markers were placed prior to five walking trials at a self-selected speed. Marker position was recorded with a motion capture system (Motion Analysis Corp), and ground reaction forces were recorded with two force platforms (Advanced Mechanical Technology Inc). The stance phase was analyzed bilaterally, and the variables were sagittal plane knee angle excursion during weight acceptance and from the end of weight-acceptance to midstance, and peak vertical ground reaction force (PVGRF) at heel strike and toe-off. Subjects self-reported knee pain intensity on the 11-point (0–10) numeric rating scale (NRS), fear of movement/re-injury on the shortened Tampa Scale for Kinesophobia (TSK-11), and pain catastrophizing on the Pain Catastrophizing Scale (PCS). Knee angle excursions and PVGRFs were compared between sides with paired t-tests. If a significant difference was found, the magnitude of asymmetry was computed (knee angle excursion: uninjured side-injured side; PVGRF (injured side/uninjured side) *100]. Pearson’s Product Moment correlation determined the association between gait asymmetry and questionnaire scores. Results: Gait variables and questionnaire scores are reported in the Table. Knee angle excursion during weight acceptance and from weight acceptance to mid-stance was reduced on the injured side compared to the uninjured side (p = 0.009 and p =.023, respectively). PVGRF at heel strike and toe-off was not significantly different between sides (p = 0.794 and p = 0.869). The asymmetry in knee angle excursion during weight acceptance was negatively correlated with NRS score (r = −0.580, p = 0.048). The asymmetry in knee angle excursion from weight acceptance to midstance was negatively correlated with TSK-11 score (r = −0.833, p = 0.001). Conclusions: Knee angle excursion on the injured side was reduced during the stance phase of gait in people with traumatic meniscal tear. During weight acceptance, knee pain intensity increased as the magnitude of asymmetry decreased; and from the end of weight acceptance until midstance, fear of movement/re-injury increased as the magnitude of asymmetry decreased. Thus, subjects with greater knee motion on the injured side displayed elevated pain and fear of movement/re-injury. These data indicate a potential link between biomechanical measures and relevant psychosocial factors from the fear- avoidance model. Although mean PVGRF was not significantly different between sides, asymmetry was as high as 12% (either under- or over- loading on the injured side) for some subjects. Table: Gait variables and questionnaire scores Injured Side Uninjured Side Points Knee angle excursion during weight acceptance (°) 12.9 (4.0) 16.1 (4.1) Knee angle excursion from weight acceptance to midstance (°) 6.3 (2.8) 8.0 (2.5) PVGRF at initial contact (N) 1105.0 (306.6) 1099.4 (282.0) PVGRF at toe-off (N) 1096.9 (298.7) 1095.2 (303.0) NRS Score 3.3 (2.3) TSK-11 Score 22.2 (5.1) PCS Score 12.9 (10.8) 182 THE EFFECTS OF CHANGES IN BODY COMPOSITION ON DYNAMIC KNEE JOINT LOADING A. Boulougouris 1 , T.B. Birmingham 2 , D. Olver 2 , P. Lemon 2 , J. Giffin 3 , K. Leitch 1 . 1 Wolf Orthopaedic Biomechanics Labratory, London, ON, Canada; 2 The Univ. of Western Ontario, London, ON, Canada; 3 Fowler Kennedy Sport Med. Clinic, London, ON, Canada Purpose: Most patients with varus gonathrosis experience aberrantly high loads on the medial compartment of the tibiofemoral joint due to the combination obesity and malalignment. Fat loss and functional strengthening programs are suggested to improve body composition and knee joint health, particularly by decreasing the load bourn by the joint during walking. The purpose of this study was to compare measures of knee function in patients with varus alignment and medial compartment knee osteoarthritis before and after a comprehensive physiotherapy program targeting changes in body composition. Methods: Twelve patients (age: 52±4yrs, BMI:31±3kg/m 2 ) with varus alignment and medial compartment knee osteoarthritis who were referred to an orthopaedic surgeon volunteered. Participants completed an 8-week, physiotherapist-supervised, group-based, lower extremity strengthening and balance program (2days/week), supplemented with fat loss and body composition seminars (1day/week). We evaluated changes in percent body fat, fat mass and lean body mass using air displacement plethysmorgraphy (Bod-Pod), knee extension and flexion strength using an isokinetic dynamometer (peak torque at 60°/sec), and walking gait using an eight-camera motion capture system synchronized with a floor-mounted force platform. We focused on gait speed, the external adduction moment about the knee, including its vertical ground reaction force and frontal plane lever arm. We also evaluated changes in the six minute walk, the lower extremity functional scale (LEFS), the Knee Injury and Osteoarthritis Outcome Score (KOOS) and the Physical Component Score of the Short Form 12 (SF-12) health status questionnaire. We evaluated mean changes with paired t-tests and 95% confidence intervals (CI). We then explored correlations between changes in selected variables. Fig. 1. Ensemble curves (n = 10) for the external knee adduction moment, vertical ground reaction force and frontal plane lever arm during stance before (dotted line) and after (solid line) the program. Results: Two participants dropped out of the study due to stated time constraints. The remaining participants completed the program without adverse events. Percent body fat (mean change; 95% CI = −3.3%; −4.4, −2.2%) and fat mass (mean change; 95% CI = −4.7 kg; −6.4, −3.0 kg) decreased without significant changes in lean body mass (mean change; 95% CI = 0.2kg; −1.5, 1.1kg). Knee extension strength (mean change; 95% CI = 35.4 Nm; 12.0, 58.8 Nm) and flexion strength (mean change; 95% CI = 25.7 Nm; 8.8, 42.6 Nm) increased. Only the KOOS pain domain (mean change; 95% CI = 8.6; 0.0, 17.5) and the SF-12 Physical Component Scores (mean change; 95% CI = 6.0; 1.4, 10.5) improved after the program. Walking speed also increased (mean change; 95% CI =0.08 m/sec; 0.0, 0.16 m/sec). Although peak vertical ground reaction force during walking did indeed decrease after the program (mean change; 95% CI =-36.7 N; −67.6, −5.9 N), the peak knee adduction moment (mean change = 2.5Nm; −2.7, 7.7 Nm) and frontal lever arm (mean change; 95% CI = −0.42cm; −1.5, 0.71cm) did not (Figure 1). The decrease in overall body mass (mean change =-4.49kg, −6.6, −2.4 kg) was significantly correlated to