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Journal of Biomechanics Jun 2016Aponeuroses are sheet-like elastic tendon structures that cover a portion of the muscle belly and act as insertion sites for muscle fibers while free tendons connect...
Aponeuroses are sheet-like elastic tendon structures that cover a portion of the muscle belly and act as insertion sites for muscle fibers while free tendons connect muscles to bones. During shortening contractions, free tendons are loaded in tension and lengthen due to the force acting longitudinally along the muscle׳s line of action. In contrast, aponeuroses increase in length and width, suggesting that aponeuroses are loaded in directions along and orthogonal to the muscle׳s line of action. Because muscle fibers are isovolumetric, they must expand radially as they shorten, potentially generating a force that increases aponeurosis width. We hypothesized that increases in aponeurosis width result from radial expansion of shortening muscle fibers. We tested this hypothesis by combining in situ muscle-tendon measurements with high-speed biplanar fluoroscopy measurements of the turkey׳s lateral gastrocnemius (n=6) at varying levels of isotonic muscle contractions. The change in aponeurosis width during periods of constant force depended on both the amount of muscle shortening and the magnitude of force production. At low to intermediate forces, aponeurosis width increased in direct proportion to fiber shortening. At high forces, aponeurosis width increased to a lesser extent or in some cases, decreased slightly during fiber shortening. Our results demonstrate that forces generated from radial expansion of shortening muscle fibers tend to drive increases in aponeurosis width, whereas longitudinal forces tend to decrease aponeurosis width. Ultimately, it is these two opposing forces that drive changes in aponeurosis width and alter series elastic stiffness during a muscle contraction.
Topics: Animals; Aponeurosis; Muscle Contraction; Muscle, Skeletal; Tendons; Turkeys
PubMed: 27155748
DOI: 10.1016/j.jbiomech.2016.04.022 -
Sbornik Lekarsky Mar 1991The plantar aponeurosis is differentiated in its most primitive form in Marsupialia, where it is formed by a single connective tissue strip, a continuation of the tendon...
The plantar aponeurosis is differentiated in its most primitive form in Marsupialia, where it is formed by a single connective tissue strip, a continuation of the tendon of the m. plantaris. The tendon is usually not fixed to the calacaneal tuberosity. The lateral tract (fibular) of the plantar aponeurosis takes a distal course and forms processes for the first to fifth toe. (The number of inserting strips is different and variable in different species of marsupials). A separate medial (tibial) strip of the aponeurosis is lacking. 2. In Insectivora the plantar aponeurosis is differentiated similarly as in marsupials. Again the medial (tibial) strip of the aponeurosis is absent and the tendon of the m. plantaris is more firmly fixed to the calcaneus. Scandentia (Tupalia) have a two-layer aponeurosis. The fibular (lateral) layer is in continuation of the tendon of the m. plantaris, the medial (tibial) layer starts at the calcaneal tuberosity. The plantar aponeurosis of Tupalia does not yet form two separable tracts, however, the forming layers of the aponeurosis indicate the future separation of the uniform connective tissue plate. 3. In prosimians and simians a separate medial (tibial) tract develops which is independent on the tendon of the m. plantaris, and in anthropoids and humans gradually the planta predominates.
Topics: Animals; Cercopithecus; Eulipotyphla; Foot; Humans; Marsupialia; Phylogeny; Pongo pygmaeus; Rodentia; Strepsirhini; Tendons
PubMed: 1904623
DOI: No ID Found -
The Journal of Foot and Ankle Surgery :... 2015Recession of the gastrocnemius aponeurosis is the operation of choice in the case of isolated gastrocnemius contracture, because it addresses the major deforming force...
Recession of the gastrocnemius aponeurosis is the operation of choice in the case of isolated gastrocnemius contracture, because it addresses the major deforming force without weakening the entire musculotendinous unit. Endoscopic recession of the gastrocnemius aponeurosis has been proved to be effective but can be associated with the wrong level of release, incomplete release, sural nerve injury, or a palpable gap at the aponeurosis. A modification of the endoscopic technique is described to provide solutions to these potential problems.
Topics: Contracture; Endoscopy; Foot Deformities; Humans; Muscle, Skeletal
PubMed: 25223945
DOI: 10.1053/j.jfas.2014.07.014 -
Annals of Anatomy = Anatomischer... May 2019Our aim was to characterize the morphology of the proximal attachment of the biceps brachii short head. We hypothesize that it has an aponeurotic component that may...
PURPOSE
Our aim was to characterize the morphology of the proximal attachment of the biceps brachii short head. We hypothesize that it has an aponeurotic component that may affect shoulder joint biomechanics.
METHODS
The coracoacromial region and the biceps brachii muscle were dissected in 30 cadaveric shoulders. The course and dimensions of the tendon and aponeurosis were evaluated. The cross-sectional area of the belly of the short head and the length of the whole muscle were measured. Correlations between the aponeurosis and dimensions of the muscle were tested with the Spearman's rank correlation coefficient.
RESULTS
Aponeurosis was present in all specimens, although in 10 cases it was vestigial. The aponeurotic part of the muscle (mean length 90.7 ± 16.3 mm, mean width 12.5 ± 2.9 mm) branched off laterally and traveled to the acromion, blending with the coracoacromial ligament creating the aponeurotic membrane. We named this structure the "superior biceps aponeurosis". The mean length of the biceps brachii was 31.3 ± 2.1 cm and the mean cross-sectional area of the short head was 210.7 ± 54.3 mm. The dimensions of the "superior biceps aponeurosis" correlated positively with the cross-sectional area of the muscle (R from 0.37 to 0.52, p from 0.014 to 0.001).
CONCLUSION
The origin of the short head of the biceps brachii muscle has a varied aponeurotic component combining the aponeurotic part of the muscle and the aponeurotic membrane. Together, they create the "superior biceps aponeurosis".
CLINICAL RELEVANCE
The morphology of the origin of the biceps brachii short head is relevant in Bristow/Latarjet procedures. This aponeurotic component may affect the shoulder joint biomechanics after the coracoid process transfer.
Topics: Acromion; Aged; Aponeurosis; Arm; Cadaver; Coracoid Process; Female; Humans; Male; Middle Aged; Muscle, Skeletal; Sex Characteristics; Shoulder Joint
PubMed: 30797975
DOI: 10.1016/j.aanat.2019.01.014 -
Adiponectin inhibits fibrosis of the palmar aponeurosis in Dupuytren's contracture in male patients.Bone & Joint Research Aug 2023Dupuytren's contracture is characterized by increased fibrosis of the palmar aponeurosis, with eventual replacement of the surrounding fatty tissue with palmar fascial...
AIMS
Dupuytren's contracture is characterized by increased fibrosis of the palmar aponeurosis, with eventual replacement of the surrounding fatty tissue with palmar fascial fibromatosis. We hypothesized that adipocytokines produced by adipose tissue in contact with the palmar aponeurosis might promote fibrosis of the palmar aponeurosis.
METHODS
We compared the expression of the adipocytokines adiponectin and leptin in the adipose tissue surrounding the palmar aponeurosis of male patients with Dupuytren's contracture, and of male patients with carpal tunnel syndrome (CTS) as the control group. We also examined the effects of adiponectin on fibrosis-related genes and proteins expressed by fibroblasts in the palmar aponeurosis of patients with Dupuytren's contracture.
RESULTS
Adiponectin expression in the adipose tissue surrounding the palmar aponeurosis was significantly lower in patients with Dupuytren's contracture than in those with CTS. The expression of fibrosis-related genes and proteins, such as types 1 and 3 collagen and α-smooth muscle actin, was suppressed in a concentration-dependent manner by adding AdipoRon, an adiponectin receptor agonist. The expression of fibrosis-related genes and proteins was also suppressed by AdipoRon in the in vitro model of Dupuytren's contracture created by adding TGF-β to normal fibroblasts collected from patients with CTS.
CONCLUSION
Fibrosis of the palmar aponeurosis in Dupuytren's contracture in males may be associated with adiponectin expression in the adipose tissue surrounding the palmar aponeurosis. Although fibroblasts within the palmar aponeurosis are often the focus of attention when elucidating the pathogenesis of Dupuytren's contracture, adiponectin expression in adipose tissues warrants closer attention in future research.
PubMed: 37536684
DOI: 10.1302/2046-3758.128.BJR-2022-0449.R1 -
International Journal of Sports Medicine Jun 2024Biceps femoris long head (BF) aponeurosis size was compared between legs with and without prior hamstring strain injury (HSI) using within-group (injured vs. uninjured...
Biceps femoris long head (BF) aponeurosis size was compared between legs with and without prior hamstring strain injury (HSI) using within-group (injured vs. uninjured legs of previous unilateral HSI athletes) and between-group (previously injured legs of HSI athletes vs. legs of No prior HSI athletes) approaches. Currently healthy competitive male athletes with Prior HSI history (=23; ≥1 verified BF injury; including a sub-group with unilateral HSI history; most recent HSI 1.6 ± 1.2 years ago) and pair-matched athletes with No prior HSI history (=23) were MRI scanned. Anonymised axial images were manually segmented to quantify BF aponeurosis and muscle size. Prior unilateral HSI athletes' BF aponeurosis maximum width, aponeurosis area, and aponeurosis:muscle area ratio was 14.0-19.6% smaller in previously injured vs. contralateral uninjured legs (paired t-test, 0.008≤≤0.044). BF aponeurosis maximum width and area were also 9.4-16.5% smaller in previously injured legs (=28) from prior HSI athletes vs. legs (=46) of No prior HSI athletes (unpaired t-test, 0.001≤≤0.044). BF aponeurosis size was smaller in legs with Prior HSI vs. those without prior HSI. These findings suggest BF aponeurosis size, especially maximum width, could be a potential cause or consequence of HSI, with prospective evidence needed to support or refute these possibilities.
PubMed: 38897227
DOI: 10.1055/a-2348-2605 -
Medicine and Science in Sports and... Jul 2015A disproportionately small biceps femoris long head (BFlh) proximal aponeurosis has been suggested as a risk factor for hamstring strain injury by concentrating...
PURPOSE
A disproportionately small biceps femoris long head (BFlh) proximal aponeurosis has been suggested as a risk factor for hamstring strain injury by concentrating mechanical strain on the surrounding muscle tissue. However, the size of the BFlh aponeurosis relative to BFlh muscle size, or overall knee flexor strength, has not been investigated. This study aimed to examine the relationship of BFlh proximal aponeurosis area with muscle size (maximal anatomical cross-sectional area (ACSAmax)) and knee flexor strength (isometric and eccentric).
METHODS
Magnetic resonance images of the dominant thigh of 30 healthy young males were analyzed to measure BFlh proximal aponeurosis area and muscle ACSAmax. Participants performed maximum voluntary contractions to assess knee flexion maximal isometric and eccentric torque (at 50° s and 350° s).
RESULTS
BFlh proximal aponeurosis area varied considerably between participants (more than fourfold, range = 7.5-33.5 cm, mean = 20.4 ± 5.4 cm, coefficient of variation = 26.6%) and was not related to BFlh ACSAmax (r = 0.04, P = 0.83). Consequently, the aponeurosis/muscle area ratio (defined as BFlh proximal aponeurosis area divided by BFlh ACSAmax) exhibited sixfold variability, being 83% smaller in one individual than another (0.53 to 3.09, coefficient of variation = 32.5%). Moreover, aponeurosis size was not related to isometric (r = 0.28, P = 0.13) or eccentric knee flexion strength (r = 0.24, P ≥ 0.20).
CONCLUSION
BFlh proximal aponeurosis size exhibits high variability between healthy young men, and it was not related to BFlh muscle size or knee flexor strength. Individuals with a relatively small aponeurosis may be at increased risk of hamstring strain injury.
Topics: Humans; Isometric Contraction; Knee; Magnetic Resonance Imaging; Male; Muscle Strength; Muscle, Skeletal; Risk Factors; Sprains and Strains; Thigh; Young Adult
PubMed: 25333248
DOI: 10.1249/MSS.0000000000000550 -
Hand Surgery : An International Journal... 2015This study aims to identify the relationship of the radial nerve as it descends across the humerus with reference to a reliable soft tissue landmark, the tricipital...
This study aims to identify the relationship of the radial nerve as it descends across the humerus with reference to a reliable soft tissue landmark, the tricipital aponeurosis. Following cadaveric dissection of 10 adult humerii, the radial nerve was located as it crossed the lateral midsagittal point of the humeral diaphysis. A horizontal line was then subtended medially from this point to another line subtended vertically from the lateral border of the tricipital aponeurosis. The vertical distance from this intersection to the lateral apex of the aponeurosis was recorded in three positions (full flexion, 90° of flexion and full extension). The location of the radial nerve on the posterior aspect of the humeral diaphysis to the medial apex of the tricipital aponeurosis was also noted. In 90° of flexion the radial nerve at the lateral midsagittal point of the humerus was 0.9 mm proximal to the lateral apex of the tricipital aponeurosis. Flexion and extension of the elbow changed the interval to 16.3 mm (nerve proximal) in full flexion and 7.1 mm in full extension (nerve distal). On the posterior aspect of the humerus the radial nerve was 21.8 mm proximal to the medial aspect of the tricipital aponeurosis. The aponeurosis provides a reference point from which the nerve can be easily located on the lateral aspect of the humerus intraoperatively in a range of positions, whilst the medial apex provides a guide to the location of the nerve on the posterior aspect of the arm.
Topics: Anatomic Landmarks; Cadaver; Humans; Humeral Fractures; Humerus; Muscle, Skeletal; Radial Nerve
PubMed: 25609275
DOI: 10.1142/S0218810415500070 -
Oral Diseases May 2014Masticatory muscle tendon-aponeurosis hyperplasia is a new disease entity associated with limited mouth opening. In this study, we analyzed the microstructural...
OBJECTIVE
Masticatory muscle tendon-aponeurosis hyperplasia is a new disease entity associated with limited mouth opening. In this study, we analyzed the microstructural characteristics of muscles and tendons in masticatory muscle tendon-aponeurosis hyperplasia by electron microscopy and energy-dispersive X-ray analysis to determine the elemental composition.
METHODS
Histological analysis was performed to detect the calcification. Transmission electron microscopy and scanning electron microscopy were conducted to clarify the microstructural characteristics of muscles and tendons. Energy-dispersive X-ray microanalysis was performed to identify the distribution of elements.
RESULTS
Mineralized nodules were observed in tendon tissues of masticatory muscle tendon-aponeurosis hyperplasia as compared with facial deformity. Electron microscopy revealed that the muscle and tendon tissues in masticatory muscle tendon-aponeurosis hyperplasia showed degenerative changes and distinctive histological findings as compared with tissues in facial deformity. We found that Ca, P, and Si were detected only in masticatory muscle tendon-aponeurosis hyperplasia.
CONCLUSION
We demonstrated that masticatory muscle tendon-aponeurosis hyperplasia exhibits heterotopic calcification in tendon tissues.
Topics: Adult; Calcinosis; Female; Humans; Hyperplasia; Masticatory Muscles; Muscular Diseases; Tendons
PubMed: 23750917
DOI: 10.1111/odi.12140 -
Annals of Plastic Surgery Mar 2021
Topics: Aponeurosis; Blepharoplasty; Blepharoptosis; Humans; Oculomotor Muscles
PubMed: 32756253
DOI: 10.1097/SAP.0000000000002496