Alexander N B, Gross M M, Medell J L, Hofmeyer M R
Geriatric Research, Education and Clinical Center, Department of Veterans Affairs Medical Center, Ann Arbor, MI 48109, USA.
J Gerontol A Biol Sci Med Sci. 2001 Sep;56(9):M538-47. doi: 10.1093/gerona/56.9.m538.
Difficulty in rising from a chair is common in older adults and may be assessed by examining the biomechanics of the rise. The purposes of this study were (i) to analyze the biomechanics of rise performance during chair-rise tasks with varying task demand in older adults with varying rise ability and (ii) to determine whether a strength-training program might improve chair-rise success and alter chair-rise biomechanics, particularly under situations of increased task demand.
A training group (n = 16; mean age, 82 years) completed a 12-week strength-training regimen while a control group (n = 14; mean age, 84 years) participated in a seated flexibility program. Outcomes included the ability to complete seven chair-rise tasks, and, if the chair-rise tasks were successful, the biomechanics of these rises. Chair-rise task demand was increased by lowering the seat height, restricting the use of hands, increasing rise speed, and limiting foot support.
At baseline, increased chair-rise task demand generally required increased task completion time, increased anterior center of pressure (COP) placement, increased momentum, increased hip flexion, and increased hip and knee torque output. Those unable to rise at 100% knee height without the use of their hands (task NH-100), compared with those able to rise during task NH-100, followed this pattern in requiring increased time, more anterior placement of the COP, and increased hip flexion to rise in the least demanding tasks allowing the use of hands. However, the unable subjects generated less momentum and knee torque in these tasks. At 12 weeks, and compared with baseline and controls, the training group demonstrated changes in chair-rise biomechanics but no significant changes in rise success. The training subjects, as compared with the controls, maintained a more posterior COP, increased their vertical and horizontal momentum, maintained their knees in greater extension, and maintained their knee-torque output.
These data demonstrate that subtle yet significant changes can be demonstrated in chair-rise performance as a result of a controlled resistance-training program. These biomechanical changes may represent a shift away from impairment in chair-rise ability, and, although the changes are small, they represent how training may reduce rise difficulty.
从椅子上起身困难在老年人中很常见，可通过检查起身的生物力学来评估。本研究的目的是：（i）分析不同起身能力的老年人在不同任务要求的椅子起身任务中起身表现的生物力学；（ii）确定力量训练计划是否可以提高从椅子上起身的成功率并改变椅子起身的生物力学，特别是在任务要求增加的情况下。
一个训练组（n = 16；平均年龄82岁）完成了为期12周的力量训练方案，而一个对照组（n = 14；平均年龄84岁）参加了坐姿灵活性计划。结果包括完成七项椅子起身任务的能力，如果椅子起身任务成功，则包括这些起身动作的生物力学。通过降低座位高度、限制手部使用、提高起身速度和限制足部支撑来增加椅子起身任务的要求。
在基线时，增加椅子起身任务要求通常需要增加任务完成时间、增加前向压力中心（COP）位置、增加动量、增加髋关节屈曲以及增加髋部和膝部扭矩输出。那些在不使用双手的情况下无法在膝盖高度100%起身的人（任务NH - 100），与那些能够在任务NH - 100中起身的人相比，在要求最低且允许使用双手的任务中起身时，也遵循这种模式，即需要更长时间、COP更靠前的位置以及更多的髋关节屈曲。然而，无法起身的受试者在这些任务中产生的动量和膝部扭矩较小。在12周时，与基线和对照组相比，训练组在椅子起身生物力学方面有变化，但起身成功率没有显著变化。与对照组相比，训练受试者保持了更靠后的COP，增加了垂直和水平动量，使膝盖保持更大程度的伸展，并保持了膝部扭矩输出。
这些数据表明，通过有控制的阻力训练计划，椅子起身表现可以出现细微但显著的变化。这些生物力学变化可能代表着从椅子起身能力受损的状态转变，尽管变化很小，但它们体现了训练如何降低起身难度。
