scholarly journals Regional Elastic Properties of the Achilles Tendon Is Heterogeneously Influenced by Individual Muscle of the Gastrocnemius

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Jiping Zhou ◽  
Jiafeng Yu ◽  
Chunlong Liu ◽  
Chunzhi Tang ◽  
Zhijie Zhang

Background. Anatomical studies and the mechanical property studies showed that there is a strong correlation between Achilles tendon (AT) elasticity and individual gastrocnemius muscle (the medial head of gastrocnemius (MG) and the lateral head of gastrocnemius (LG)) elasticity. Limited ankle dorsiflexion range of motion has been correlated with decreased flexibility of the MG/LG/AT complex. However, no studies have been conducted to examine the exact correlation between the Achilles tendon and the individual muscle of the gastrocnemius. Purposes. The purposes of the present study were (1) to evaluate intra- and interoperator reliabilities of elastic property measurements in the gastrocnemius muscle-Achilles tendon complex by using the shear wave elastography (SWE) and (2) to examine the correlation between the regional elastic properties of the AT and the individual muscle of the gastrocnemius. Methods. Twenty healthy subjects (mean age: 22.50 (3.02) years) were recruited in this study. The elastic properties of the AT and the individual muscle of the gastrocnemius were quantified using the SWE. Findings. The SWE has comparatively high reliability in quantifying the elastic properties of the muscle-tendon range from good to excellent. The intraoperator ICC of the gastrocnemius muscle-Achilles tendon complex was 0.77 to 0.95, while the interoperator ICC was 0.76 to 0.94. The minimal detectable change (MDC) of the muscle was 1.72 kPa, while the AT was 32.90 kPa. A significant correlation was found between the elastic modulus of AT and the elastic modulus of the MG (r=0.668 and p=0.001 at the relaxing position and r=0.481 and p=0.032 at the neutral position). Conclusions. The SWE has the potential to assess localized changes in muscle-tendon elastic properties, provide more intuitive relations between elastic properties of the muscle tendon and function, and evaluate the therapeutic effect of the muscle tendon. A significant correlation between the AT and the MG was found, and it may provide a new treatment idea (targeted to the tight muscle heads) for the clinical setting to treat subjects with AT disorders.

2021 ◽  
Vol 12 ◽  
Author(s):  
Weiyi Pan ◽  
Jiping Zhou ◽  
Yuyi Lin ◽  
Zhijie Zhang ◽  
Yulong Wang

The elastic properties of the Achilles tendon (AT) are altered in local injury or other diseases and in response to changes in mechanical load. Recently, elastography has been used to evaluate variations in tendon elastic properties, mainly among healthy individuals or athletes. Therefore, this study evaluated the biomechanical changes in ATs in individuals with and without plantar fasciitis (PF). The purposes were as follows: (1) to evaluate the passive stiffness of three regions of the AT which defined as 0 (AT0 cm), 3 (AT3 cm), and 6 cm (AT6 cm) above the calcaneal tuberosity in participants with and without PF, (2) to investigate the interplay between the passive stiffness in patients with PF and pain, (3) to detect optimal cut-off points of stiffness of the AT in assessing individuals with chronic PF, and (4) to determine the correlation between the plantar fascia thickness (PFT) and pain. This cross-sectional study included 40 participants (mean age = 51 ± 13 years). When the ankle was in a relaxed position, patients with PF experienced increased passive stiffness in AT0 cm (p = 0.006) and AT3 cm (P = 0.003), but not in the neutral position. Significant correlations were observed between pain and stiffness of AT (AT0 cm r = 0.489, P = 0.029; AT3 cm r = 487, P = 0.030; AT6 cm r = 0.471, P = 0.036), but not in the PFT (P = 0.557). Optimal cut-off stiffness was AT (452 kPa) in the relaxed ankle position. The plantar fascia of patients with PF was significantly thicker than that of the controls (P < 0.001). Findings from the present study demonstrate that tendon stiffness is a good indicator of the clinical situation of patients with PF. Monitoring passive tendon stiffness may provide additional information to assess severity of the condition and guide therapeutic. The treatment programs for PF should also be tailored to the distal AT, as conventional therapy might not be targeted to tight tendons.


2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Jun Zhang ◽  
Jiafeng Yu ◽  
Chunlong Liu ◽  
Chunzhi Tang ◽  
Zhijie Zhang

Background. Neck and shoulder complaints caused by poor posture may influence upper trapezius stiffness. The relationship between the shear elastic modulus of the upper trapezius and cervical flexion angles is unknown. Therefore, it is essential to assess upper trapezius stiffness during cervical flexion. The objectives of this study were to (1) determine the intra- and interoperator reliabilities of evaluating upper trapezius stiffness and calculate the minimal detectable change (MDC); (2) examine the elastic modulus alterations of the upper trapezius during cervical flexion; and (3) explore the difference of upper trapezius stiffness between the dominant and nondominant sides. Methods. Twenty healthy male participants were recruited in this study. The shear modulus of the upper trapezius was evaluated by two independent investigators using shear wave elastography (SWE) during cervical flexion at 0° and 50°. Findings. The intraoperator (intraclass correlation coefficient ICC=0.85–0.86) and interoperator (ICC=0.94–0.98) reliabilities for measuring the shear elastic modulus of the upper trapezius during the cervical flexion ranged from good to excellent. An increase of 35.58% in upper trapezius stiffness was found at 0° to 50° of cervical flexion, and the MDC was 7.04 kPa. In addition, a significant difference was obtained in the elastic modulus of the upper trapezius muscle between the dominant and nondominant sides (P<0.05). Conclusions. Our findings revealed that SWE could quantify the elastic modulus of the upper trapezius and monitor its changes. Therefore, further studies are required to delineate the modulation in upper trapezius muscle stiffness among subjects with neck and shoulder pain.


Healthcare ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 80
Author(s):  
Masatoshi Nakamura ◽  
Ryosuke Kiyono ◽  
Shigeru Sato ◽  
Kaoru Yahata ◽  
Taizan Fukaya ◽  
...  

Background: Previous studies suggest that the capacity for rapid force production of ankle plantar flexors is essential for the prevention of falls in the elderly. In healthy young adults, there were significant associations between rate of force development and muscle stiffness measured by shear wave elastography. However, there has been no study investigating the association of rate of force development with shear elastic modulus in older adults. Methods: The muscle strength and shear elastic modulus of the medial gastrocnemius muscle in both legs were measured in 17 elderly men and 10 elderly women (mean ± SD; 70.7 ± 4.1 years; 160.6 ± 8.0 cm; 58.7 ± 9.5 kg). We investigated the rate of force development of plantar flexors and shear elastic modulus of medial gastrocnemius muscle using by shear wave elastography. Results: Our results showed that there were no significant associations between normalized rate of force development and shear elastic modulus of medial gastrocnemius muscle. Conclusion: This suggests that the capacity of rapid force production could be related not to muscle stiffness of the medial gastrocnemius muscle, but to neuromuscular function in older individuals.


PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3592 ◽  
Author(s):  
Wilson K.C. Leung ◽  
KL Chu ◽  
Christopher Lai

BackgroundMechanical loading is crucial for muscle and tendon tissue remodeling. Eccentric heel drop exercise has been proven to be effective in the management of Achilles tendinopathy, yet its induced change in the mechanical property (i.e., stiffness) of the Achilles tendon (AT), medial and lateral gastrocnemius muscles (MG and LG) was unknown. Given that shear wave elastography has emerged as a powerful tool in assessing soft tissue stiffness with promising intra- and inter-operator reliability, the objective of this study was hence to characterize the stiffness of the AT, MG and LG in response to an acute bout of eccentric heel drop exercise.MethodsForty-five healthy young adults (36 males and nine females) performed 10 sets of 15-repetition heel drop exercise on their dominant leg with fully-extended knee, during which the AT and gastrocnemius muscles, but not soleus, were highly stretched. Before and immediately after the heel drop exercise, elastic moduli of the AT, MG and LG were measured by shear wave elastography.ResultsAfter the heel drop exercise, the stiffness of AT increased significantly by 41.8 + 33.5% (P < 0.001), whereas the increases in the MG and LG stiffness were found to be more drastic by 75 + 47.7% (P < 0.001) and 71.7 + 51.8% (P < 0.001), respectively. Regarding the AT, MG and LG stiffness measurements, the inter-operator reliability was 0.940, 0.987 and 0.986, and the intra-operator reliability was 0.916 to 0.978, 0.801 to 0.961 and 0.889 to 0.985, respectively.DiscussionThe gastrocnemius muscles were shown to bear larger mechanical loads than the AT during an acute bout of eccentric heel drop exercise. The findings from this pilot study shed some light on how and to what extent the AT and gastrocnemius muscles mechanically responds to an isolated set of heel drop exercise. Taken together, appropriate eccentric load might potentially benefit mechanical adaptations of the AT and gastrocnemius muscles in the rehabilitation of patients with Achilles tendinopathy.


2022 ◽  
Author(s):  
Jiping Zhou ◽  
Yuyi Lin ◽  
Jiehong Zhang ◽  
Xingxian Si’tu ◽  
Ji Wang ◽  
...  

Abstract The mechanical properties of deep fascia (i.e. an index of stiffness) strongly affect the development of muscle pathologies, and muscular actions, such as compartment syndromes. Actually, a clear understanding of the mechanical characterization of muscle deep fascia still lacks. The present study focuses on examining the reliability of ultrasonic shear wave elastography device (USWE) in quantifying the shear modulus of gastrocnemius fascia in healthy individual and the device’s abilities to examine the shear modulus of gastrocnemius deep fascia during ankle dorsiflexion. Twenty-one healthy males participated in the study (age: 21.48±1.17 years). The shear modulus of the medial gastrocnemius fascia (MGF) and lateral gastrocnemius fascia (LGF) were quantified at different angles using USWE during passive lengthening. The operators took turns to measure each subject’s MGF and LGF over 1-hour period and by operator B with a 2-hour interval. In the intra-operator test, the same subjects participated at the same time 5 days later. The intra-rater [ Intra-class correlation coefficient (ICC) = 0.846-0.965)] and inter-rater (ICC = 0.877-0.961) reliabilities for measuring the shear modulus of the MGF and LGF were rated as both excellent, and the standard error in measurement (SEM) was 3.49 kPa, the minimal detectable change (MDC) was 9.68 kPa. Regardless of the ankle angle, the shear modulus of the LGF were significant greater than that of the MGF (p < 0.001). The significant increase in the shear modulus both of the MGF and LGF were observed at neutral position compared to the relaxed position. This results indicate that the USWE is a technique to assess the shear modulus of gastrocnemius fascia and detect its dynamic changes during ankle dorsiflexion. USWE can be used for biomechanical study and intervention experiments of deep fascia.


Diagnostics ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1015
Author(s):  
Antonio Bulum ◽  
Gordana Ivanac ◽  
Eugen Divjak ◽  
Iva Biondić Špoljar ◽  
Martina Džoić Dominković ◽  
...  

Shear wave elastography (SWE) is a type of ultrasound elastography with which the elastic properties of breast tissues can be quantitatively assessed. The purpose of this study was to determine the impact of different regions of interest (ROI) and lesion size on the performance of SWE in differentiating malignant breast lesions. The study included 150 female patients with histopathologically confirmed malignant breast lesions. Minimal (Emin), mean (Emean), maximal (Emax) elastic modulus and elasticity ratio (e-ratio) values were measured using a circular ROI size of 2, 4 and 6 mm diameters and the lesions were divided into large (diameter ≥ 15 mm) and small (diameter < 15 mm). Highest Emin, Emean and e-ratio values and lowest variability were observed when using the 2 mm ROI. Emax values did not differ between different ROI sizes. Larger lesions had significantly higher Emean and Emax values, but there was no difference in e-ratio values between lesions of different sizes. In conclusion, when measuring the Emin, Emean and e-ratio of malignant breast lesions using SWE the smallest possible ROI size should be used regardless of lesion size. ROI size has no impact on Emax values while lesion size has no impact on e-ratio values.


Author(s):  
María Carmen Sánchez-González ◽  
Raquel García-Oliver ◽  
José-María Sánchez-González ◽  
María-José Bautista-Llamas ◽  
José-Jesús Jiménez-Rejano ◽  
...  

In our work, we determined the value of visual acuity (VA) with ETDRS charts (Early Treatment Diabetic Retinopathy Study). The purpose of the study was to determine the measurement reliabilities, calculating the correlation coefficient interclass (ICC), the value of the error associated with the measure (SEM), and the minimal detectable change (MDC). Forty healthy subjects took part. The mean age was 23.5 ± 3.1 (19 to 26) years. Visual acuities were measured with ETDRS charts (96% ETDRS chart nº 2140) and (10% SLOAN Contrast Eye Test chart nº 2153). The measurements were made (at 4 m) under four conditions: Firstly, photopic conditions with high contrast (HC) and low contrast (LC) and after 15 min of visual rest, mesopic conditions with high and low contrast. Under photopic conditions and high contrast, the ICC = 0.866 and decreased to 0.580 when the luminosity and contrast decreased. The % MDC in the four conditions was always less than 10%. It was minor under photopic conditions and HC (5.83) and maximum in mesopic conditions and LC (9.70). Our results conclude a high reliability of the ETDRS test, which is higher in photopic and high contrast conditions and lower when the luminosity and contrast decreases.


Author(s):  
Jacopo Quaglierini ◽  
Alessandro Lucantonio ◽  
Antonio DeSimone

Abstract Nature and technology often adopt structures that can be described as tubular helical assemblies. However, the role and mechanisms of these structures remain elusive. In this paper, we study the mechanical response under compression and extension of a tubular assembly composed of 8 helical Kirchhoff rods, arranged in pairs with opposite chirality and connected by pin joints, both analytically and numerically. We first focus on compression and find that, whereas a single helical rod would buckle, the rods of the assembly deform coherently as stable helical shapes wound around a common axis. Moreover, we investigate the response of the assembly under different boundary conditions, highlighting the emergence of a central region where rods remain circular helices. Secondly, we study the effects of different hypotheses on the elastic properties of rods, i.e., stress-free rods when straight versus when circular helices, Kirchhoff’s rod model versus Sadowsky’s ribbon model. Summing up, our findings highlight the key role of mutual interactions in generating a stable ensemble response that preserves the helical shape of the individual rods, as well as some interesting features, and they shed some light on the reasons why helical shapes in tubular assemblies are so common and persistent in nature and technology. Graphic Abstract We study the mechanical response under compression/extension of an assembly composed of 8 helical rods, pin-jointed and arranged in pairs with opposite chirality. In compression we find that, whereas a single rod buckles (a), the rods of the assembly deform as stable helical shapes (b). We investigate the effect of different boundary conditions and elastic properties on the mechanical response, and find that the deformed geometries exhibit a common central region where rods remain circular helices. Our findings highlight the key role of mutual interactions in the ensemble response and shed some light on the reasons why tubular helical assemblies are so common and persistent.


2004 ◽  
Vol 178 (4) ◽  
pp. 197-203 ◽  
Author(s):  
Tetsuro Muraoka ◽  
Tadashi Muramatsu ◽  
Tetsuo Fukunaga ◽  
Hiroaki Kanehisa

A novel theory is proposed to show how a crack may he accelerated or retarded when it meets an interface between two equally brittle materials of different elastic properties. Measurements of a model crack travelling through a brittle adhesive joint have substantially verified the theory. The results demonstrate that the toughness of a composite material, having a periodic stiffness change along the crack path, may be very much greater than the toughness of the individual components of the composite. The relevance of these ideas to the design of tough composite structures is discussed.


Sign in / Sign up

Export Citation Format

Share Document