目的 探讨老年人上下楼梯的步态特征以及下肢关节运动的力学性能。 方法 通过17名青年人、15名老年人自然速度上下5个台阶的楼梯测试与分析,并结合红外高速运动捕捉系统和三维测力台获取步态参数、下肢关节角度以及地面反作用力,通过逆向动力学方法计算关节力矩和功率,采取独立样本 t 检验分析年龄对上述参数的影响。 结果 与青年人相比,老年人上下楼梯步态周期较长,步速和步频则明显较低(P<0. 05);同时,老年人上下楼梯支撑相和摆动相分别明显延长和缩短(P<0. 05)。 不论是青年人还是老年人,上下楼梯过程中下肢关节角度、力矩和功率的变化趋势较为一致。 但老年人上楼主要是通过踝、膝关节功率的产生来维持,而青年人则是通过近端肢体的能量,特别动用了较多的膝关节功率。 下楼过程中的能量吸收,两者皆是以膝关节为主。 结论 随着年龄的增长,下肢机能下降和肌力不足,老年人害怕在上下楼梯时发生跌倒,试图通过减少摆动时间来弥补身体的不稳定。 研究结果为临床上老年患者群体的康复管理以及预测跌倒的功能性评估提供参考。

Objective To investigate gait characteristics of older adults during stair ascent and descent, and mechanical properties of lower extremity joint movement. Methods A total of 17 young adults and 15 old adults were required to ascend and descend a five-step staircase at natural walking speed. The gait parameters, lower limb joint angles and ground reaction force were obtained using infrared high speed motion capture system and three-dimensional force platform, the joint moments and powers were calculated by inverse dynamics approach, and the influence of age on those parameters was analyzed by independent samples t-test. Results Compared with young adults, older adults had a relatively longer gait cycle, as well as an obviously lower walking speed and frequency during stair ascent and decent (P<0.05). Meanwhile, the support phase and swing phase in older adults during stair ascent and decent were obviously prolonged and shortened respectively (P<0.05). The change trend for joint angle, moment and power of lower limbs during stair ascent and decent was consistent in both young and older adults. However, during stair ascent, older adults were mainly maintained by the generation of ankle and knee joint power, while young adults were mainly maintained by the energy at the proximal limb, especially more knee power was used. For older and young adults, energy absorption during stair decent played an important role in knee joints. Conclusions With aging, lower limb function and muscle strength will decrease. Older adults are afraid of falling down during stair ascent and decent, and try to compensate for the instability of the body by reducing swinging time. The research findings provide references for rehabilitation management and functional assessment on fall prediction of older patient populations in clinical practice.

浙江省基础公益研究计划项目(LGF18C100003)