■慢性踝关节不稳定(CAI)是一种从急性踝关节扭伤演变而来的肌肉骨骼疾病,其基本机制尚未达成共识。越来越多的证据表明,踝关节损伤后大脑的神经可塑性变化在CAI的发展中起着关键作用。平衡不足是与CAI相关的重要风险因素,然而,关于受累个体的感觉运动皮质可塑性与平衡控制相关的证据却很少。这项研究旨在评估CAI患者和未受伤个体在单腿站立时的皮层活动和平衡能力的差异,以及这些因素之间的相关性,为了阐明CAI患者平衡控制的神经生理学改变。
■该研究招募了24名CAI患者和24名未受伤的参与者。在单腿站立时,使用功能近红外光谱(fNIRS)系统测量皮质活动,其中包括对运动前皮层(PMC)的评估,辅助电机区域(SMA),初级运动皮层(M1),和初级体感皮层(S1)。同时,利用三维力平台测试平衡参数。
■独立样本t检验表明,与未受伤的人相比,CAI患者在单腿站立期间在通道5的左S1内表现出氧合血红蛋白浓度变化(ΔHbO)的显着增加(t=2.101,p=0.041,Cohen\sd=0.607),第6频道的左侧M1(t=2.363,p=0.022,科恩的d=0.682),第15频道的右M1(t=2.273,p=0.029,科恩的d=0.656),右侧PMC/SMA位于第11频道(t=2.467,p=0.018,Cohen\sd=0.712)。此外,CAI患者中外侧(ML)方向的压力均方根(COP-RMS)中心明显更大(t=2.630,p=0.012,Cohen\'sd=0.759)。此外,在M1(r=0.436;p=0.033)和PMC/SMA(r=0.488,p=0.016)的ML方向COP-RMS和ΔHbO2之间存在中度正相关,以及在M1中的前后(AP)方向COP-RMS和ΔHbO之间(r=0.483,p=0.017)。
■CAI患者显示双侧M1,同侧PMC/SMA的皮质激活增加,和对侧S1。这表明CAI患者在单腿站立时可能需要额外的大脑资源来保持平衡,代表在踝关节横向平衡能力减弱的情况下维持任务表现的代偿机制。
UNASSIGNED: Chronic Ankle Instability (CAI) is a musculoskeletal condition that evolves from acute ankle sprains, and its underlying mechanisms have yet to reach a consensus. Mounting evidence suggests that neuroplastic changes in the brain following ankle injuries play a pivotal role in the development of CAI. Balance deficits are a significant risk factor associated with CAI, yet there is a scarcity of evidence regarding the sensorimotor cortical plasticity related to balance control in affected individuals. This study aims to evaluate the differences in cortical activity and balance abilities between patients with CAI and uninjured individuals during a single-leg stance, as well as the correlation between these factors, in order to elucidate the neurophysiological alterations in balance control among patients with CAI.
UNASSIGNED: The study enrolled 24 patients with CAI and 24 uninjured participants. During single-leg stance, cortical activity was measured using a functional near-infrared spectroscopy (fNIRS) system, which included assessments of the pre-motor cortex (PMC), supplementary motor area (SMA), primary motor cortex (M1), and primary somatosensory cortex (S1). Concurrently, balance parameters were tested utilizing a three-dimensional force platform.
UNASSIGNED: Independent sample t-tests revealed that, compared with the uninjured individuals, the patients with CAI exhibited a significant increase in the changes of oxyhemoglobin concentration (ΔHbO) during single-leg stance within the left S1 at Channel 5 (t = 2.101, p = 0.041, Cohen\'s d = 0.607), left M1 at Channel 6 (t = 2.363, p = 0.022, Cohen\'s d = 0.682), right M1 at Channel 15 (t = 2.273, p = 0.029, Cohen\'s d = 0.656), and right PMC/SMA at Channel 11 (t = 2.467, p = 0.018, Cohen\'s d = 0.712). Additionally, the center of pressure root mean square (COP-RMS) in the mediolateral (ML) direction was significantly greater (t = 2.630, p = 0.012, Cohen\'s d = 0.759) in the patients with CAI. Furthermore, a moderate positive correlation was found between ML direction COP-RMS and ΔHbO2 in the M1 (r = 0.436; p = 0.033) and PMC/SMA (r = 0.488, p = 0.016), as well as between anteroposterior (AP) direction COP-RMS and ΔHbO in the M1 (r = 0.483, p = 0.017).
UNASSIGNED: Patients with CAI demonstrate increased cortical activation in the bilateral M1, ipsilateral PMC/SMA, and contralateral S1. This suggests that patients with CAI may require additional brain resources to maintain balance during single-leg stance, representing a compensatory mechanism to uphold task performance amidst diminished lateral balance ability in the ankle joint.