1.INFLUENCE OF FOOT POSITION ON KNEE VALGUS DURING FEINTING IN TEAM HANDBALL
ORIE YAMAGUCHI ; YUKIO URABE ; YUKI YAMANAKA ; NATSUMI KAMIYA ; SHIGEYUKI KATO
Japanese Journal of Physical Fitness and Sports Medicine 2009;58(5):537-544
Purpose: To determine whether performing a feint in team handball with a wide foot stance leads to a greater knee valgus angle and/or knee valgus moment.Methods: Eight women handball players performed a feint with 4 different foot stances (free and 30%, 40%, and 50% of their body height). Three-dimensional kinematics and ground reaction forces were measured during the feints. Hip abduction angle at first contact, peak vertical ground reaction force, peak knee valgus angle, and peak external knee valgus moment during the first 20% of the feint cycle were compared among the stances at 30%, 40%, and 50% of body height (ANOVA, P<0.05). In the free feint, we investigated intrasubject correlations among foot stance and hip abduction angle at first contact, peak knee valgus angle, and peak external knee valgus moment were then conducted (P<0.05).Results: When performing a feint with foot stances at 40% and 50% of body height, the subjects had significantly greater peak external knee valgus moment. Hip abduction angle at first contact was significantly correlated to peak knee valgus angle and peak external knee valgus moment.Conclusion: Training athletes to avoid wide foot stance and large hip abduction angle may reduce the risk of sustaining noncontact anterior cruciate ligament injuries.
2.THE EFFECTS OF VARIOUS ANGULAR VELOCITIES ON KNEE KINESTHESIA
MIYUKI MIYAZATO ; YUKIO URABE ; YUKI YAMANAKA ; YASUYUKI UEDA ; ORIE YAMAGUCHI ; KANA KANAI ; HIROAKI KIMURA
Japanese Journal of Physical Fitness and Sports Medicine 2008;57(5):563-568
In this study, we investigated whether a difference in the angular velocity has an effect on proprioceptive sensibility in 30 healthy subjects. Knee detection of passive motion at five angular velocities (0.1°/s, 0.2°/s, 0.3°/s, 0.4°/s, and 0.5°/s) was carried out from a starting position of 15° knee flexion for extension using a proprioception testing device. At 0.1°/s, the elapsed time was longer than that of the other angular velocities and the angular displacement was bigger as well. There were no significant differences among the remaining angular velocities (0.2~0.5°/s). Therefore it is suggested that a healthy knee has less proprioception at an angular velocity of 0.1°/s.