Hosseinabadi Mostafa, Salehi Reza, Azadinia Fatemeh, Ghandhari Hasan, Jalali Maryam
Rehabilitation Research Center, Department of Orthotics and Prosthetics, School of Rehabilitation Sciences, Iran University of Medical Sciences, Tehran, Iran.
Geriatric Mental Health Research Center, Iran University of Medical Sciences, Tehran, Iran.
Sci Rep. 2025 Sep 26;15(1):32975. doi: 10.1038/s41598-025-12002-w.
Center-of-pressure (CoP) oscillations represent the neuromuscular system's response to control the body's center of mass. In older adults, hyperkyphosis alters body alignment, increases sway, and impairs proprioception. While some studies have explored hyperkyphosis effects on CoP displacements, the underlying neuromuscular mechanisms remain underexplored. This studyinvestigated hyperkyphosis impacts on the postural control using the stabilogram diffusion analysis (SDA) to assess interplay between open and closed-loop control. Thirty-eight older adults with a mean kyphosis angle of 57.8 ± 8.4° and 34 controls with a mean kyphosis angle of 38.4 ± 4.9°, participated. CoP parameters, including trajectory range, velocity in the anterior-posterior (AP), mediolateral (ML), and planar (R) directions, sway area per unit time, and SDA, were measured during bipedal standing in eyes-open (EO) and eyes-closed (EC) conditions. Results showed significantly higher short-term effective diffusion coefficients in the ML (p = 0.016), AP (p = 0.011), and R-directions (p = 0.007), as well as critical displacement in the AP-direction (p = 0.048), and CoP velocity in R-direction (p = 0.046) in the hyperkyphotic group. Conversely, critical time interval in R-direction (p = 0.034) was lower compared to controls. EC increased short-term effective diffusion coefficient in all directions, critical displacement in the AP, and R-directions, sway area per unit time, CoP velocity in all directions, trajectory range in the AP (p < 0.001) and ML-directions (p = 0.047). EO showed higher long-term diffusion coefficients in the AP and R-directions (p < 0.001), and critical time intervals in the AP (p = 0.014) and R-direction (p = 0.003). Hyperkyphosis impairs open-loop control and reliance on closed-loop mechanisms, potentially delays responses and increases fall risk in older adults.
压力中心（CoP）振荡代表神经肌肉系统对控制身体重心的反应。在老年人中，脊柱后凸加剧会改变身体 alignment，增加摇摆，并损害本体感觉。虽然一些研究探讨了脊柱后凸加剧对CoP位移的影响，但其潜在的神经肌肉机制仍未得到充分研究。本研究使用稳定图扩散分析（SDA）来评估开环和闭环控制之间的相互作用，从而研究脊柱后凸加剧对姿势控制的影响。38名平均脊柱后凸角度为57.8±8.4°的老年人和34名平均脊柱后凸角度为38.4±4.9°的对照组参与了研究。在睁眼（EO）和闭眼（EC）条件下双足站立期间，测量了CoP参数，包括轨迹范围、前后（AP）、内外侧（ML）和平面（R）方向的速度、单位时间的摇摆面积以及SDA。结果显示，脊柱后凸加剧组在ML方向（p = 0.016）、AP方向（p = 0.011）和R方向（p = 0.007）的短期有效扩散系数显著更高，以及AP方向的临界位移（p = 0.048）和R方向的CoP速度（p = 0.046）也显著更高。相反，与对照组相比，R方向的临界时间间隔（p = 0.034）更低。EC增加了所有方向的短期有效扩散系数、AP和R方向的临界位移、单位时间的摇摆面积、所有方向的CoP速度、AP方向（p < 0.001）和ML方向（p = 0.047）的轨迹范围。EO在AP和R方向显示出更高的长期扩散系数（p < 0.001），以及AP方向（p = 0.014）和R方向（p = 0.003）的临界时间间隔。脊柱后凸加剧会损害开环控制并增加对闭环机制的依赖，可能会延迟反应并增加老年人的跌倒风险。
