Increased postural sway is often observed in people with mild traumatic brain injury (mTBI), but our understanding of how individuals with mTBI control their head during stance is limited. The purpose of this study was to determine if people with mTBI exhibit increased sway at the head compared with healthy controls. People with persisting symptoms after mTBI (n = 59, 41 women) and control participants (n = 63, 38 women) stood quietly for one minute in four conditions: eyes open on a firm surface (EO-firm), eyes closed on a firm surface (EC-firm), eyes open on a foam pad (EO-foam), and eyes closed on foam (EC-foam). Inertial sensors at the head, sternum, and lumbar region collected tri-axial accelerations. Root-mean-square (RMS) accelerations in anteroposterior (AP) and mediolateral (ML) directions and sway ratios between the head and sternum, head and lumbar, and sternum and lumbar region were compared between groups. Temporal coupling of anti-phase motion between the upper and lower body angular accelerations was assessed with magnitude squared coherence and cross-spectral phase angles. People with mTBI demonstrated greater sway than controls across conditions and directions. During foam-surface conditions, the control group, but not the mTBI group, reduced ML sway at their head and trunk relative to their lumbar by increasing the expression of an anti-phase hip strategy within the frontal plane. These results are consistent with suggestions of inflexible or inappropriate postural control in people with mTBI.

在轻度创伤性脑损伤 (mTBI) 患者中经常观察到姿势摇摆增加，但我们对 mTBI 患者在站立时如何控制头部的了解有限。本研究的目的是确定与健康对照组相比，mTBI 患者的头部摆动是否增加。mTBI 后症状持续存在的人（n  = 59，41名女性）和对照参与者（n = 63, 38 名女性）在四种情况下安静地站立一分钟：在坚硬的表面上睁眼（EO-firm），在坚硬的表面上闭上眼睛（EC-firm），在泡沫垫上睁眼（EO-foam） , 闭上眼睛盯着泡沫 (EC-foam)。头部、胸骨和腰部区域的惯性传感器收集三轴加速度。比较各组间前后（AP）和中间（ML）方向的均方根（RMS）加速度以及头与胸骨、头与腰椎、胸骨和腰椎区域之间的摇摆比。上半身和下半身角加速度之间反相运动的时间耦合通过幅度平方相干性和交叉光谱相位角进行评估。mTBI 患者在条件和方向上表现出比对照组更大的影响力。在泡沫表面条件下，对照组，但不是 mTBI 组，通过增加额平面内反相位髋关节策略的表达，减少了头部和躯干相对于腰椎的 ML 摇摆。这些结果与 mTBI 患者不灵活或不适当的姿势控制的建议一致。