Techniques for In Vivo Measurement of Ligament and Tendon Strain: A Review

Abstract

The critical clinical and scientific insights achieved through knowledge of in vivo musculoskeletal soft tissue strains has motivated the development of relevant measurement techniques. This review provides a comprehensive summary of the key findings, limitations, and clinical impacts of these techniques to quantify musculoskeletal soft tissue strains during dynamic movements. Current technologies generally leverage three techniques to quantify in vivo strain patterns, including implantable strain sensors, virtual fibre elongation, and ultrasound. (1) Implantable strain sensors enable direct measurements of tissue strains with high accuracy and minimal artefact, but are highly invasive and current designs are not clinically viable. (2) The virtual fibre elongation method tracks the relative displacement of tissue attachments to measure strains in both deep and superficial tissues. However, the associated imaging techniques often require exposure to radiation, limit the activities that can be performed, and only quantify bone-to-bone tissue strains. (3) Ultrasound methods enable safe and non-invasive imaging of soft tissue deformation. However, ultrasound can only image superficial tissues, and measurements are confounded by out-of-plane tissue motion. Finally, all in vivo strain measurement methods are limited in their ability to establish the slack length of musculoskeletal soft tissue structures. Despite the many challenges and limitations of these measurement techniques, knowledge of in vivo soft tissue strain has led to improved clinical treatments for many musculoskeletal pathologies including anterior cruciate ligament reconstruction, Achilles tendon repair, and total knee replacement. This review provides a comprehensive understanding of these measurement techniques and identifies the key features of in vivo strain measurement that can facilitate innovative personalized sports medicine treatment.

Modelling and in vivo evaluation of tendon forces and strain in dynamic rehabilitation exercises: a scoping review

“…32 However, transducer position may affect the ultrasound measurements significantly, and it is necessary to use a rigid fixation over the tissue that may alter movement patterns. 33 Therefore, its use in some dynamic activities is still limited. Some reviews have been previously published focused on the evaluation of tendon loads.…”

“…23 Additionally, ultrasonography enables the differentiation of muscle and tendon interfaces, enabling muscle and tendon strains to be independently measured. 33 Basically, two approaches could be used to analyse strain using imaging techniques: on the one hand, displacement measurements between the tendon origin and insertion anatomical sites (myotendinous junction), approach used in this review by Rees et al 68 and Chaudhry et al 55 The tracking of these anatomical sites is done through different methods. Initially, this task was performed through manual marking of the anatomical sites in successive ultrasound frames throughout the movement.…”

“…However, these strain sensors share many of their limitations with other implantable devices and must be biotolerable, biocompatible and easy to implant. 33 Vibrational behaviour A proof-of-concept study was identified with a novel technique for evaluating tendon force during walking, running and unilateral and bilateral heel raising. 113 Tendon loads were measured using a vibration motor and an accelerometer placed 2 cm apart from each other on the skin superior to the Achilles tendon.…”

“… 38 39 Some of these methods have been adapted to the study of dynamic exercises (such as rehabilitation exercises), but the study of this type of exercises is still scarce due to the limitations of these tools. 33 Therefore, there is still a lack of studies addressing the direct measurement of loads and the evaluation of dynamic exercises commonly used during rehabilitation processes.…”

Special Issue: 50th Anniversary of ABME

“…ABME aims to cover interdisciplinary research across all topics in biomedical engineering, which is reflected in these scientific reviews. Significant review papers from the past two years have analyzed advancements in ultrasound technology, 2 macrophage polarization, 14 bone tissue engineering, 10 biodegradable 3D dental constructs, 12 uterosacral ligament mechanics, 4 placental research, 15 cardiovascular 3D printing, 6 digital human models in vehicle collisions, 13 drone lacerations, 5 biomimetic bone graft 3D printing, 3 solar UV exposure sensors, 8 ligament and tendon strain measurement, 16 surgical drill bit design, 1 upper limb prostheses sensors, 9 and mechanical regulation of cardiovascular apoptosis. 7 ABME continues to receive high quality submissions, which is reassuring for the future success of ABME towards promoting critical scientific advancements to propel the field forward.…”