Nyland John, Smith Steve, Beickman Kurt, Armsey Thomas, Caborn David N M
Division of Sports Medicine, Department of Orthopaedic Surgery, University of Louisville, Louisville, KY 40292, USA.
Med Sci Sports Exerc. 2002 Jul;34(7):1150-7. doi: 10.1097/00005768-200207000-00016.
Center of plantar pressure (COPP) location moves toward the forefoot as ankle plantar flexor muscles attempt to maintain postural control during single leg stance. This study evaluated relationships between frontal plane tibiofemoral joint angulation during relaxed bilateral stance and mean COPP locations during vision-denied single leg stance at 20 degrees knee flexion.
Fifty-six nonimpaired athletes (29 female, 27 male) were evaluated for frontal plane tibiofemoral joint angulation and standing foot angle by using two-dimensional videography (30 Hz). Mean anterior-posterior and mediolateral COPP locations were assessed during single leg stance on a mat (25 Hz, 15 s). One-way ANOVA and Tukey HSD tests evaluated group differences (P < or = 0.05) based on frontal plane tibiofemoral joint angulation.
Group 1 (genu varus or genu valgus < 5 degrees ) displayed a mean anterior-posterior COPP location of 54.2 +/- 6% from the (0,0) coordinate starting point at the anterolateral foot (10.3 +/- 2 cm from the posterior sensor edge). Group 2 (genu varus angulation > or = 5 degrees ) and group 3 subjects (genu valgus angulation > or = 5 degrees ) displayed mean anterior-posterior COPP locations of 60.6 +/- 8% and 60.7 +/- 7% (8.8 +/- 2 cm and 8.7 +/- 2 cm from the posterior sensor edges), respectively. Group 2 (12.5 +/- 3 N x kg(-1)) and group 3 (12.4 +/- 3.1 N x kg(-1)) subjects also displayed greater mean plantar force magnitude/body weight than group 1 (10.3 +/- 2 N x kg(-1)) subjects. Mean ankle plantar flexor moment magnitudes did not differ between groups.
Rearfoot directed mean anterior-posterior COPP locations and greater plantar force magnitudes/body weight suggests that subjects with genu varus or genu valgus relied more on the subtalar and midtarsal joint control function of the ankle plantar flexor muscle group for lower extremity dynamic postural control.
在单腿站立期间，当踝跖屈肌试图维持姿势控制时，足底压力中心（COPP）位置会向前足移动。本研究评估了在放松的双侧站立期间，膝关节屈曲20度时，矢状面胫股关节角度与视觉剥夺单腿站立期间平均COPP位置之间的关系。
使用二维摄像（30Hz）对56名无损伤的运动员（29名女性，27名男性）进行矢状面胫股关节角度和站立足角度评估。在垫子上进行单腿站立时（25Hz，15秒），评估COPP在前后和内外侧的平均位置。单向方差分析和Tukey HSD检验根据矢状面胫股关节角度评估组间差异（P≤0.05）。
第1组（膝内翻或膝外翻<5度）在距前外侧足（0,0）坐标起始点的前后方向上，COPP平均位置为54.2±6%（距后传感器边缘10.3±2厘米）。第2组（膝内翻角度≥5度）和第3组受试者（膝外翻角度≥5度）的前后方向COPP平均位置分别为60.6±8%和60.7±7%（距后传感器边缘8.8±2厘米和8.7±2厘米）。第2组（12.5±3N·kg-1）和第3组（12.4±3.1N·kg-1）受试者的平均足底力大小/体重也高于第1组（10.3±2N·kg-1）受试者。各组间平均踝跖屈力矩大小无差异。
后足方向的前后COPP平均位置以及更大的足底力大小/体重表明，膝内翻或膝外翻受试者在下肢动态姿势控制中更多地依赖踝跖屈肌群的距下和中跗关节控制功能。
