Relationship Between Structure and Age in Healthy Achilles Tendons

Area of Science:

• Musculoskeletal biology
• Biomechanics
• Gerontology

Background:

• Age-related changes in Achilles tendon structure can influence lower limb function and mobility.
• Distinguishing age-related structural changes from those associated with tendon pathology is challenging.

Purpose of the Study:

• To investigate the relationship between age and the structural properties of healthy Achilles tendons.
• To establish normative data for Achilles tendon structure across a wide age range.

Main Methods:

• Retrospective analysis of 389 healthy Achilles tendons from individuals aged 8-79 years.
• B-mode ultrasound to assess tendon length, cross-sectional area (CSA), and thickness.
• Continuous shear wave elastography to evaluate shear modulus and viscosity.
• General Linear Models and White's test used to determine age-related relationships, controlling for sex, weight, and physical activity.

Main Results:

• Healthy Achilles tendon length, thickness, CSA, and viscosity significantly increased with age (p < 0.05).
• Full Achilles tendon length and CSA showed significant variation across the age span (p < 0.05).
• Findings support natural aging processes affecting Achilles tendon structure and mechanical properties.

Conclusions:

• Age is associated with significant structural alterations in the healthy Achilles tendon, including increased length, thickness, CSA, and viscosity.
• These age-related changes may impact the tendon's ability to store and transfer energy, potentially affecting function in older adults.
• Normative data on age-related Achilles tendon structure can inform the understanding of injury pathogenesis and guide prevention/treatment strategies.