rated positive correlations in dynamic knee valgus kinematics and task-elicited pain across five tasks. Movement and pain during the clinical test of single-limb squat test also was correlated with movement and pain during the functional tasks of stair ascent/descent and sit-to-stand. Level 2b.Level 2b. Sports rehabilitation professionals often prescribe unstable objects for balance training. Unfortunately, there is a lack of measurement of balance confidence when incorporating these objects. Currently, there is no consensus on the optimal balance confidence measure or proposed progression of unstable objects. Understanding the influence of balance confidence on task performance using unstable objects may help professionals better prescribe a balance training program. The primary purpose of this investigation was to explore the correlation between anticipated and actual balance confidence on different unstable objects during static double leg and single leg stance. The secondary purpose was to explore the correlation between anticipated and actual unstable object difficulty rankings. Repeated measure observational, controlled trial. Sixty-five active, healthy adults (M = 35, F = 30) (mean age = 24.38 ± 3.56) underwent two testing sessions. During session one, participants took an online survey, ratinsy)- ground, Level 2- foam pad, Level 3- air-filled discs, Level 4- Bosu®, and Level 5 (difficult)- wobble board. Study findings suggest that actual measures of balance confidence may provide insight into a patient's confidence level and may help with prescribing and progressing their program. The suggested unstable object difficulty rankings may help professionals better match the objects to their patients to produce optimal outcomes. 2c.2c. Standardized testing of hip muscle strength and fatigue in the sagittal plane is important for assessing, treating and preventing a number of trunk and lower extremity pathologies. Furthermore, individuals displaying asymmetries of muscle strength between limbs are more likely to sustain an injury. To evaluate the test-retest reliability of isometric strength and isokinetic fatigue measurements of the hip flexor and hip extensor muscles, and to examine whether there is a significant limb dominance effect on strength, fatigue and flexor-extensor ratios. Cross-sectional study. To evaluate reliability, 30 healthy individuals (33.2 + /- 13.1 years) were included. On a separate occasion, 24 healthy individuals (29.0 + /- 10.3 years) participated to assess between-limb differences. Reliability was established using intraclass correlation coefficients (ICCs), standard error of measurements (SEM) and minimal detectable change (MDC). Isometric strength (best peak torque of three maximal contractions; Nm/kg), isokinetic fatigue (total work of 20 consecutive maximal concentric flexor-extensor contractions at 120 °/s; Joule/kg), and flexor-extensor ratios, were recorded using a Biodex dynamometer. Reliability was good-to-excellent (ICCs>0.83) and measurement errors were acceptable (SEM<13.6% and MDC%<37.8%). No significant between-limb differences in strength, fatigue and flexor-extensor ratios were detected. Isometric strength and isokinetic fatigue of the hip flexor and hip extensor muscles can be reliably assessed in healthy individuals using the Biodex dynamometer. Limb dominance did not significantly affect strength, fatigue or flexor-extensor ratios. 2b.2b. Despite abundant literature, the treatment of iliotibial band syndrome (ITBS) in cyclists remains complicated as it lacks evidence-based recommendations. The aim of this study was to develop a musculoskeletal modelling approach that investigates three potential biomechanical determinants of ITBS (strain, strain rate and compression force) and to use this approach to investigate the effect of saddle setback. Cross-sectional. An existing 3D lower-body musculoskeletal model was adapted to cycling and to the computation of three putative pathomechanisms responsible for ITBS ITB strain, ITB strain rate, and compression force between ITB and the lateral femoral epicondyle (LFE). Lower limb kinematics recorded from ten well-trained healthy cyclists served as input data of the model. PF-06700841 manufacturer Cyclists pedalled at a steady state (90rpm and 200W) on an ergometer, and three different saddle setback conditions were tested. The theoretical combined influence of hip and knee joint angles on ITBS was investigated and analysed through the lens of individual pedalling technique. ITB-LFE compression force was the only parameter significantly affected by saddle setback and supports the hypothesis that compression force is likely to be a determinant factor in ITBS etiology. Furthermore, results showed that ITB-LFE compression force increases in individuals whose pedalling technique exacerbates hip extension-adduction and/or knee extension-internal rotation. This approach has the potential to be advantageously implemented as an additional tool to help diagnose/correct potentially harmful sport techniques and optimize equipment setup/design. 3b.3b. Hamstring strain injuries are common in many sports. Following a hamstring injury, deficits in peak and explosive strength may persist after return to sport potentially affecting sprint performance. Assessment of repeated-sprint ability is recognized as an important part of the return to sport evaluation after a hamstring injury.Purpose This purpose of this exploratory cross-sectional study was to compare sprinting performance obtained during a repeated-sprint test between football players with and without a previous hamstring strain injury. Forty-four fully active sub-elite football players, 11 with a previous hamstring strain injury during the preceding 12 months (cases; mean age, SD 25.6 ± 4.4) and 33 demographically similar controls (mean age, SD 23.2 ± 3.7), were included from six clubs. All players underwent a repeated-sprint test, consisting of six 30-meter maximal sprints with 90 seconds of recovery between sprints. Sprint performance was captured using high-speed video-recording and subsequently assessed by a blinded tester to calculate maximal sprint velocity, maximal horizontal force, maximal horizontal power, and mechanical effectiveness.