Strain Assessment of Deep Fascia of the Thigh During Leg Movement: An in situ Study

Abstract

Fascia is a fibrous connective tissue present all over the body. At the lower limb level, the deep fascia that is overlying muscles of the outer thigh and sheathing them (fascia lata) is involved in various pathologies. However, the understanding and quantification of the mechanisms involved in these sheathing effects are still unclear. The aim of this study is to observe and quantify the strain field of the fascia lata, including the iliotibial tract (ITT), during a passive movement of the knee. Three fresh postmortem human subjects were studied. To measure hip and knee angles during knee flexion-extension, passive movements from 0 • to around 120 • were recorded with a motion analysis system and strain fields of the fascia were acquired using digital image correlation. Strains were computed for three areas of the fascia lata: anterior fascia, lateral fascia, and ITT. Mean principal strains showed different strain mechanisms depending on location on the fascia and knee angle. For anterior and lateral fascia, a tension mechanism was mainly observed with major strain greater than minor strain in absolute value. While for the ITT, two strain mechanisms were observed depending on knee movement: tension is observed when the knee is extended relatively to reference position of 47 • , however, pure shear can be observed when the knee is flexed. In some cases, minor strain can also be higher than major strain in absolute value, suggesting high tissue compression probably due to microstructural fiber rearrangements. This in situ study is the first attempt to quantify the superficial strain field of fascia lata during passive leg movement. The study presents some limitations but provides a step in understanding strain mechanism of the fascia lata during passive knee movement.

First-in-human demonstration of floating EMG sensors and stimulators wirelessly powered and operated by volume conduction

“…To accomplish this, the needle had to be completely inserted as longitudinal as possible to the muscle, in acute angle with the skin and the muscle fascia. Remarkably, the muscle fascia is an anisotropic connective tissue (36)(37)(38) that has higher stiffness and strain in the longitudinal than the transverse direction (39). This implies that the needle and the thin guiding filament may have faced higher mechanical resistance in this insertion scenario than in the typical scenario of use for this kind of thin-film electrodes (i.e., perpendicular to the muscle).…”

Stretch tolerance and elastic passive reaction of the quadriceps femoris seem to depend more on the fascia profundis taut surfaces than on the underlying stretched muscle

“…Also, the lengthening of the stretched tissue was limited by participant pain or discomfort (Germain et al, 2020). Despite extensive studies on RF and FL anatomy and biomechanics (Birnbaum et al, 2004; Gyaran et al, 2011; Jensen & Davy, 1975; Otsuka et al, 2018; Spoor & van Leeuwen, 1992; Stecco et al, 2013; Terry et al, 1986) and further research on FL strain fields (Sednieva et al, 2019; Sednieva et al, 2020), the structure limiting stretch intensity remains unknown (Nordez et al, 2017). The limiting structure is likely to be the muscle or fascia profundis (Nordez et al, 2017; Stecco et al, 2021).…”

“…Free nerve endings, Pacini and Ruffini corpuscles, and other tissues provide links to intramuscular Golgi sensors, giving the fascia proprioceptive and nociceptive capacities (Suarez‐Rodriguez et al, 2022). The FL inserts into the patella and tibia (Birnbaum et al, 2004; Stecco et al, 2013; Terry et al, 1986), and the strain field of the FL changes significantly with knee flexion (Sednieva et al, 2019; Sednieva et al, 2020).…”

“…The moment arm generated by the anterior thigh at hip level should increase with knee flexion: knee flexion induces hip flexion, increasing the moment arm of the RF and FL (Schmitz et al, 2016). However, if the FL is the limiting structure, the tolerated tension should reduce with increased knee flexion; most lateral areas appear more relaxed with knee flexion (Sednieva et al, 2019; Sednieva et al, 2020). As the main strain directions of the lateral FL are not parallel to its longitudinal fibers (Otsuka et al, 2018; Otsuka et al, 2020), increased knee flexion reduces the FL taut area.…”

Donor-Site Morbidity After Autologous Fascia Lata Harvest for Arthroscopic Superior Capsular Reconstruction: A Midterm Follow-up Evaluation

“…During hip and knee movements, the fascia lata tissue sustains high strains in multiple directions, and its resistance and elasticity make it an attractive and versatile autograft. 37 , 43 When harvested postmortem, the fascia lata loses a large percentage of its proteoglycans, which has an effect on its viscoelastic properties, 43 highlighting the importance of in vivo AFL harvesting.…”