Nichols D S
Physical Therapy Division, School of Allied Medical Professions, Ohio State University, Columbus 43210, USA.
Phys Ther. 1997 May;77(5):553-8. doi: 10.1093/ptj/77.5.553.
Balance is a somewhat ambiguous term used to describe the ability to maintain or move within a weight-bearing posture without falling. Balance can further be broken down into three aspects: steadiness, symmetry, and dynamic stability. Steadiness refers to the ability to maintain a given posture with minimal extraneous movement (sway). The term symmetry is used to describe equal weight distribution between the weight-bearing components (eg, the feet in a standing position, the buttocks in a sitting position), and dynamic stability is the ability to move within a given posture without loss of balance. All of these components of balance (steadiness, symmetry, and dynamic stability) have been found to be disturbed following stroke. Balance testing of patients with hemiparesis secondary to stroke has revealed a greater amount of postural sway during static stance, asymmetry with greater weight on the nonparetic leg, and a decreased ability to move within a weight-bearing posture without loss of balance. Furthermore, research has demonstrated moderate relationships between balance function and gait speed (r = -.67 and .42, respectively), independence (r = .62), appearance (defined as "significantly abnormal," "slightly abnormal," and "nearly normal") (r = .50), dressing (r.55-.69), wheelchair mobility (r = .51), and reaching (r = .49-.78). Thus, a principal construct within physical therapy practice is the reestablishment of balance function in patients following stroke. Recent advances in technology have resulted in the commercial availability of numerous force platform systems for the retraining of balance function in patient populations, including patients with stroke. These systems are designed to provide visual or auditory biofeedback to patients regarding the locus of their center of force (COF) or center of pressure (COP), as well as training protocols to enhance stance symmetry, steadiness, and dynamic stability. Typical force platform biofeedback systems consist of at least two force plates to allow the weight on each foot to be determined, a computer and monitor to allow visualization of the COF or COP, and software that provides training protocols and data analysis capabilities. Some units allow auditory feedback in addition to the visual feedback in response to errors in performance.
平衡是一个有点模糊的术语，用于描述在负重姿势下保持或移动而不摔倒的能力。平衡可进一步细分为三个方面：稳定性、对称性和动态稳定性。稳定性是指以最小的额外运动（晃动）保持给定姿势的能力。对称性一词用于描述负重部件之间的重量均匀分布（例如，站立时的双脚、坐姿时的臀部），而动态稳定性是指在给定姿势下移动而不失平衡的能力。已发现中风后平衡的所有这些组成部分（稳定性、对称性和动态稳定性）都会受到干扰。对中风继发偏瘫患者的平衡测试显示，静态站立时姿势晃动更多，非瘫痪侧腿负重更大导致不对称，以及在负重姿势下移动而不失平衡的能力下降。此外，研究表明平衡功能与步态速度（分别为r = -0.67和0.42）、独立性（r = 0.62）、外观（定义为“明显异常”、“轻微异常”和“接近正常”）（r = 0.50）、穿衣（r = 0.55 - 0.69）、轮椅移动性（r = 0.51）和伸手够物（r = 0.49 - 0.78）之间存在中等程度的相关性。因此，物理治疗实践中的一个主要理念是恢复中风患者的平衡功能。技术的最新进展已使众多用于患者群体（包括中风患者）平衡功能再训练的力平台系统投入商业使用。这些系统旨在向患者提供关于其力中心（COF）或压力中心（COP）位置的视觉或听觉生物反馈，以及增强站立对称性、稳定性和动态稳定性的训练方案。典型的力平台生物反馈系统至少由两个测力板组成，以确定每只脚上的重量，一台计算机和显示器用于显示COF或COP，以及提供训练方案和数据分析功能的软件。一些设备除了视觉反馈外，还允许在性能出现错误时提供听觉反馈。
