After an Achilles tendon (AT) injury, the decision to return to full weightbearing for the practice of sports or strenuous activities is based on clinical features only. In this study, tendon stiffness and foot plantar pressure, as objective quantitative measures that could potentially inform clinical decision making, were repeatedly measured in 15 patients until 3 months after the AT rupture by using shear wave elastography (SWE) and wearable insoles, respectively. Meanwhile, patient reported outcomes assessing the impact on physical activity were evaluated using the Achilles Tendon Total Rupture Score (ATRS). At week-2 post-injury, stiffness of the injured tendon varied from 6.00 ± 1.62 m/s (mean ± SD) close to the rupture to 8.91 ± 2.29 m/s when measured more distally. While near complete recovery was observed in distal and middle regions at week-8, the shear wave velocity in the proximal region recovered to only 65% of the contralateral value at week-12. In a parallel pre-clinical study, the tendon stiffness measured in vivo by SWE in a rat model was found to be strongly correlated with ex vivo values of the Young’s modulus, which attests to the adequacy of SWE for these measures. The insole derived assessment of the plantar pressure distribution during walking showed slight sub-optimal function of the affected foot at week-12, while the ATRS score recovered to a level of 59 ± 16. Significant correlations found between tendon stiffness, insole variables and distinct ATRS activities, suggest clinical relevance of tendon stiffness and foot plantar pressure measurements. These results illustrate how an alteration of the AT structure can impact daily activities of affected patients and show how digital biomarkers can track recovery in function over time.

跟腱（AT）受伤后，决定恢复完全负重进行运动或剧烈运动的决定仅基于临床特征。在这项研究中，分别使用剪切波弹性成像（SWE）和可穿鞋垫对15例患者进行了反复测量，直到15个月后直到3个月，才对肌腱刚度和足底压力进行了客观测量，从而可能为临床决策提供依据。同时，使用跟腱腱断裂总评分（ATRS）评估患者报告的评估其对身体活动影响的结果。受伤后第2周，受伤的肌腱的刚度从接近破裂处的6.00±1.62 m / s（平均值±SD）变化到更远端测量的8.91±2.29 m / s。在第8周时，在远端和中部区域观察到接近完全恢复，而在第12周时，近端区域的剪切波速度仅恢复到对侧值的65％。在一项平行的临床前研究中，发现在大鼠模型中通过SWE在体内测得的肌腱刚度与体外杨氏模量值密切相关，这证明了SWE在这些措施中是否足够。鞋垫在步行过程中对足底压力分布的评估显示，患足在第12周出现轻微的次佳功能，而ATRS评分恢复到59±16的水平。在肌腱刚度，鞋垫变量和不同部位之间发现了显着相关性ATRS活动提示肌腱僵硬和足底压力测量的临床相关性。