Grafts placed too anteriorly on the femur are reportedly a common cause of failure in anterior cruciate ligament reconstruction. Some studies suggest more anatomic femoral tunnel placement improves kinematics. The ability of the transtibial technique and a tibial tunnel-independent technique (placed transfemorally outside-in) to place the guide pin near the center of the femoral attachment of the anterior cruciate ligament was compared in 12 cadavers. After arthroscopic placement of the guide pins, the femur was dissected and the three-dimensional geometry of the femur, anterior cruciate ligament footprint, and positions of each guide pin were measured. The transtibial guide-pin placement was 7.9 ± 2.2 mm from the center of the footprint (near its anterior border), whereas the independent technique positioned the guide pin 1.9 ± 1.0 mm from the center. The center of the footprint was within 2 mm of an anteroposterior line through the most posterior border of the femoral cartilage in the notch and a proximodistal line through the proximal margin of the cartilage at the capsular reflection. More accurate placement of the femoral tunnel might reduce the incidence of graft failure and might reduce long-term degeneration observed after reconstruction although both would require clinical confirmation.

Significant differences in forefoot loading patterns existed between cleat types. Based on the results of this study, it might be beneficial to increase the forefoot cushioning in cleats in an attempt to decrease loading in these regions of the foot.

Groin pain is a common cause of athletic disability and often involves the adductor longus. A common complaint of patients with groin problems is pain while preparing to kick the ball. The purpose of this study was to examine muscle length and activation of the adductor longus while kicking a soccer ball. Three-dimensional joint positions and muscle activation were obtained from 15 National Collegiate Athletic Association (NCAA) Division 1 male soccer players during maximal effort kicks. Musculoskeletal modeling techniques incorporating joint position and muscle attachments were used to estimate adductor longus length from the beginning of the kicking leg's swing phase until ball strike. The maximum rate of stretch of the adductor longus (22.3 +/- 5.3 cm/s) and maximum hip extension (23.3 +/- 8.80) occurred near 40% of swing phase. Activation of the adductor longus occurred between 10% and 50% of the swing phase. Adductor longus maximum length occurred at 65% of the swing phase. Maximum hip abduction (25.3 +/- 5.40) occurred at 80% of swing phase. The adductor longus appears to be at risk of strain injury during its transition from hip extension to hip flexion. This knowledge could be applied to muscle injury prevention and rehabilitation programs to aid with treatment of adductor longus related groin pain.