Scannell Joan P, McGill Stuart M
University of Waterloo, Waterloo, Ontario, Canada.
Phys Ther. 2003 Oct;83(10):907-17.
Physical therapists commonly attempt to reduce and prevent low back pain by "improving" individuals' lumbar posture. To investigate the physical therapy clinical practice of attempting to "improve" lumbar posture, measures of passive tissue stiffness and angular deformation during activities of daily living were used.
The lumbar spine posture of 150 university students was measured as the inclinometer angle difference between L1 and S1. Eighteen female participants (6 with hypolordosis, 6 with hyperlordosis, and 6 controls without lumbar spine impairment) were recruited from this lumbar posture database. Hypolordosis and hyperlordosis were clinically classified by physical therapists.
Lumbar passive tissue stiffness was measured during sitting, standing, and walking before and after a 12-week exercise program, and estimates of lumbar passive tissue strain were calculated from those measurements.
The neutral zone (NZ), a range of lumbar positions of low passive tissue stiffness, was identified. Prior to training, the subjects with hypolordosis had more passive tissue strain during sitting than the subjects with hyperlordosis, and the subjects with hyperlordosis stood in extension relative to their NZs while the control subjects and subjects with hypolordosis stood within their NZs. Before and after training, subjects in all 3 groups walked with lumbar spine positions within their NZs. After training, the lumbar posture of the subjects with hypolordosis and the subjects with hyperlordosis changed toward a "mean" (mid-range) lumbar posture. After the exercise program, subjects in all 3 groups stood and walked with their lumbar spines in positions within their NZs, and they sat with their lumbar spines flexed relative to their NZs.
Knowing that tissue failure can be related to passive tissue strain, the results of this study support the clinical practice of attempting to change individuals' posture-related lumbar spine positions during activities of daily living. Lumbar passive tissue strain, as estimated from the NZ and angular deformation during activities of daily living, can be decreased, but can also be increased, by an exercise program.
物理治疗师通常试图通过“改善”个体的腰椎姿势来减轻和预防腰痛。为了研究试图“改善”腰椎姿势的物理治疗临床实践，采用了日常生活活动中被动组织僵硬度和角变形的测量方法。
测量了150名大学生的腰椎姿势，即L1和S1之间的倾角计角度差。从该腰椎姿势数据库中招募了18名女性参与者（6名腰椎前凸减少者、6名腰椎前凸增加者和6名无腰椎损伤的对照组）。腰椎前凸减少和增加由物理治疗师进行临床分类。
在为期12周的运动计划前后，测量了坐姿、站姿和行走时的腰椎被动组织僵硬度，并根据这些测量结果计算腰椎被动组织应变的估计值。
确定了中性区（NZ），即低被动组织僵硬度的腰椎位置范围。训练前，腰椎前凸减少的受试者在坐姿时比腰椎前凸增加的受试者有更多的被动组织应变，腰椎前凸增加的受试者相对于其NZ处于伸展站立状态，而对照组受试者和腰椎前凸减少的受试者则站在其NZ范围内。训练前后，所有3组受试者行走时腰椎位置均在其NZ范围内。训练后，腰椎前凸减少的受试者和腰椎前凸增加的受试者的腰椎姿势向“平均”（中间范围）腰椎姿势转变。运动计划后，所有3组受试者站立和行走时腰椎均处于其NZ范围内的位置，坐姿时腰椎相对于其NZ处于屈曲状态。
鉴于组织损伤可能与被动组织应变有关，本研究结果支持在日常生活活动中试图改变个体与姿势相关的腰椎位置的临床实践。根据NZ和日常生活活动中的角变形估计的腰椎被动组织应变，可通过运动计划降低，但也可能增加。
