The purpose of this study was to investigate age-related differences in Achilles tendon loading during gait. Fourteen young (7F/7M, 26 ± 5 years) and older (7F/7M, 67 ± 5 years) adults without current neurological or orthopaedic impairment participated. Shear wave tensiometry was used to measure tendon stress by tracking Achilles tendon wave speed. The wave speed-stress relationship was calibrated using simultaneously collected tensiometer and force plate measures during a standing sway task. Tendon stress was computed from the force plate measures using subject-specific ultrasound measures of tendon moment arm and cross-sectional area. All subjects exhibited a highly linear relationship between wave speed squared and tendon stress (mean R2 > 0.9), with no significant age-group differences in tensiometer calibration parameters. Tendon wave speed was monitored during treadmill walking at four speeds (0.75, 1.00, 1.25, and 1.50 m/s) and used to compute the stress experienced by the tendon. Relative to young adults, older adults exhibited 22% lower peak tendon wave speeds. Peak tendon stress during push-off in older adults (24.8 MPa) was 32% less than that in the young adults (36.7 MPa) (p = 0.01). There was a moderate increase (+11%) in peak tendon stress across both groups when increasing speed from 0.75 to 1.50 m/s (main effect of speed, p = 0.01). Peak tendon loading during late swing did not differ between age groups (mean 3.8 MPa in young and 4.2 MPa in older adults). These age-related alterations in tendon tissue loading may affect the mechanobiological stimuli underlying tissue remodeling and thereby alter the propensity for tendon injury and disease.

中文翻译：

---

在各种步行速度范围内，老年人的跟腱负荷都低于年轻人。


本研究的目的是调查步态过程中跟腱负荷与年龄相关的差异。目前没有神经或骨科损伤的 14 名年轻（​​7F/7M，26 ± 5 岁）和老年（7F/7M，67 ± 5 岁）成年人参与了研究。剪切波张力测定法通过跟踪跟腱波速来测量肌腱应力。在站立摇摆任务期间，使用同时收集的张力计和测力台测量值来校准波速-应力关系。使用肌腱力臂和横截面积的受试者特定超声测量结果，根据测力板测量值计算肌腱应力。所有受试者都表现出波速平方和肌腱应力之间的高度线性关系（平均值 R2 > 0.9），张力计校准参数没有显着的年龄组差异。在跑步机上以四种速度（0.75、1.00、1.25 和 1.50 m/s）行走期间监测肌腱波速，并用于计算肌腱所承受的应力。与年轻人相比，老年人的峰值肌腱波速度低 22%。老年人推出时肌腱峰值应力 (24.8 MPa) 比年轻人 (36.7 MPa) 低 32% (p = 0.01)。当速度从 0.75 增加到 1.50 m/s 时，两组的峰值肌腱应力都有适度增加 (+11%)（速度的主效应，p = 0.01）。摇摆后期的肌腱峰值负荷在不同年龄组之间没有差异（年轻人平均为 3.8 MPa，老年人平均为 4.2 MPa）。这些与年龄相关的肌腱组织负荷变化可能会影响组织重塑的机械生物学刺激，从而改变肌腱损伤和疾病的倾向。