Lower limb joint alignment and postural control in elderly women

The aim of this study was to test whether quiet stance body sway is associated with ankle and knee joint angles in elderly women. Joint angles were measured using a manual goniometer and body sway was assessed using a force platform and four postural tasks with a combination of feet positions and eye condition. The sample (N = 58) showed the following angle values: 102 (100-104) for the tibiotarsal joint, 176 (174-180) for the subtalar joint, 184 (181-187) for knee flexion-extension, and 13 (10-15) for the Q-angle. Q-angle was significantly correlated (p < 0.05) with center of foot pressure (CP) displacement area (r = 0.36), anteroposterior (SDy, r = 0.34) and lateral (SDx, r = 0.31) CP standard deviation, and anteroposterior CP range (r = 0.38) during the closed base, eyes opened trial (CBEO). The valgus group showed statistically higher values than the normal and varus groups for SDy (0.56 vs. 0.52 and 0.46 mm; p = 0.02), SDx (0.55 vs. 0.49 and 0.36 mm; p = 0.02) and anteroposterior range (3.32 vs. 2.78 and 2.38 mm; p = 0.01), CBEO. The displacement velocity of the CP was significantly higher for the asymmetric than the symmetric Q-angle group (8.0 vs. 5.3 mm/s - closed base, eyes closed trial). Knee alignment was correlated with measures of body sway in elderly women, but ankle alignment showed no correlation. Knee morphology should be considered an associated factor for quiet stance postural control.

本研究旨在探究老年女性静息站立时的身体晃动与踝关节、膝关节角度是否存在相关性。研究采用手动测角仪（manual goniometer）测量关节角度，通过测力台（force platform）结合不同足位与视线条件组合的四项姿势任务，评估受试者的身体晃动情况。本研究纳入的58名受试者，其关节角度测量值如下：胫距关节（tibiotarsal joint）角度为102（四分位区间100~104），距下关节（subtalar joint）角度为176（174~180），膝关节屈伸角度为184（181~187），Q角（Q-angle）为13（10~15）。在闭基睁眼（CBEO, closed base, eyes opened trial）任务中，Q角与足底压力中心（CP, center of foot pressure）位移面积（r=0.36）、前后向CP标准差（SDy，r=0.34）、内外向CP标准差（SDx，r=0.31）以及前后向CP活动范围（r=0.38）均存在显著相关性（p<0.05）。外翻组（valgus group）在CBEO任务中的前后向CP标准差（0.56 vs. 0.52、0.46 mm；p=0.02）、内外向CP标准差（0.55 vs. 0.49、0.36 mm；p=0.02）以及前后向CP活动范围（3.32 vs. 2.78、2.38 mm；p=0.01）均显著高于正常组与内翻组（varus group）。不对称Q角组的CP位移速度显著高于对称Q角组（8.0 vs. 5.3 mm/s，闭基闭眼任务）。本研究结果显示，老年女性的膝关节对线情况与身体晃动指标存在相关性，而踝关节对线则无此关联，因此膝关节形态应被视为静息站立姿势控制的相关影响因素。