Tensile properties of fresh human calcaneal (achilles) tendons

Abstract

The purpose of this study was to measure the tensile properties of fresh human calcaneal (Achilles) tendons. Twenty fresh cadaveric (age range = 57-93 years) bone-Achilles tendon complexes were harvested within 24 hr postmortem. The calcaneus together with 15 cm of the Achilles tendon extending proximally from the insertion on the calcaneus was clamped and biomechanically tested. Each tendon was firmly fixed in clamps in an MTS Systems Corporation MTS testing machine and tension was applied at a displacement rate of 8 cm per minute until the tendon failed. The tensile force and tensile strain (as measured using an extensometer) were recorded and plotted using onboard software. The narrow age range of our donors prevented any meaningful correlation between age and tensile properties; however, the results showed that: 1) the average ultimate tensile strength (UTS) of the human Achilles tendon was 1189 N (range = 360-1,965), 2) there was a correlation between left and right legs for UTS, 3) there was a correlation between left and right legs in regard to cross sectional area, and 4) there was no correlation between UTS and cross-sectional area.

Tendon-Derived Extracellular Matrix Enhances Transforming Growth Factor-β3-Induced Tenogenic Differentiation of Human Adipose-Derived Stem Cells

“…For instance, although aligned scaffold demonstrated anisotropy similar to that of tendon tissue, improvements in tensile strength (*26 MPa) are clearly needed if intended to be used as a clinical tendon graft (*550 MPa). 58 In addition, functional in vivo implant likely requires a scaffold that sufficiently retains bioactive agents. For this purpose, scaffold surface modification may be carried out to immobilize bioactive macromolecules contained in tECM.…”

On the suitability of Thiel‐fixed samples for biomechanical purposes: Critical considerations on the articles of Liao et al. “elastic properties of Thiel‐embalmed human ankle tendon and ligament” and Verstraete et al. “impact of drying and thiel embalming on mechanical properties of achilles tendons”

“…However, their conclusions differ to large extent, which might cause some confusion for the readership and raises issues surrounding standardized testing of soft tissue material in anatomy and biomechanical research. While Liao et al (2015) reported decreased elasticity in six Thiel-fixed calcaneal tendons when compared with existing data on native ones (Louis-Ugbo et al, 2004;Verstraete et al, 2015) showed an increased Young's modulus in Thiel-embalmed calcaneal tendons compared with fresh ones from matched pairs. Both studies do have an apparent overlap in their data with loading rate-dependent properties ranging between 62.23 6 18.96 to 272.82 6 86.61 MPa (0.25%/s to 8%/s) (Liao et al, 2015) and 152.25 6 50.68 MPa (static loading with no further information given) (Verstraete et al, 2015), though the strains at which the material properties were computed were different.…”

Effect of tendon stiffness on the generated force at the Achilles tendon - 3D finite element simulation of a human triceps surae muscle during isometric contraction

“…The generated forces ranged from 467.5 to 676.2 N. The stiffer tendon generated higher force at the Achilles tendon than the low-stiffness tendon, and the largest generated force was 1.45 times greater than the smallest one. , 2004, b: Rosager et al, 2002, c: Reeves et al, 2005 …”

“…(13) We selected some experimental results on the Achilles tendon material response from the several literatures (Louis- Ugbo et al, 2004;Rosager et al, 2002;Reeves et al, 2005;Shin et al, 2008), and identified the material parameters in Eq. (7), by using the least-squares method.…”

“…This paper describes 3D FE-model of a human triceps surae muscle investigation in which we have attempted to examine how the tendon stiffness, within the range indicated in several literatures (Louis-Ugbo et al, 2004;Rosager et al, 2002;Reeves et al, 2005;Shin et al, 2008), may influence the generated forces at the Achilles tendon of contracting skeletal muscle. Such 3D FE-model obtained from in vivo real human leg non-invasively is particularly challenging in the relatively complex structure of human triceps surae muscle, which is composed of different structural components with a complex arrangement of muscle fiber orientation (Kawakami et al, 1998).…”