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Background/Objectives: Osteoarthritis (OA) is a chronic and progressive joint disease, leading to functional limitations and significantly impairing the quality of life. Muscle weakness, reduced mobility, and compensatory biomechanical changes are common consequences, further exacerbating functional decline. The aim of this study was to assess the impact of hip osteoarthritis on muscle functionality and to evaluate the effectiveness of hip arthroplasty using the MyotonPro device to measure key biomechanical parameters, i.e., tension, stiffness, and flexibility. Methods: This cohort study included 40 patients (17 women and 23 men; mean age 64.55 ± 10.49 years) with advanced hip OA (Kellgren–Lawrence grade III–IV) undergoing hip arthroplasty. Measurements of muscle tension (F), stiffness (S), and flexibility (D) in the gluteus maximus, rectus femoris, and biceps femoris were performed at three time points: before surgery, on postoperative days 8–10, and one month after hospital discharge. Pain (VAS), balance (Tinetti scale), and functional ability (WOMAC index) were also assessed. Results: Hip arthroplasty significantly reduced pain levels (VAS: 6.38 ± 0.28 preoperatively to 1.88 ± 0.22 postoperatively, p < 0.001) and improved functional ability (WOMAC: p < 0.001). Muscle tension and stiffness of the gluteus maximus initially increased after surgery (tension: 11.57 ± 0.32 to 12.15 ± 0.38, p = 0.009), reflecting compensatory stabilization but decreased by the final evaluation. Flexibility improved significantly over time (p = 0.014). The biceps femoris muscle exhibited a significant reduction in tension one month postoperatively (p = 0.015), alongside decreased stiffness (p = 0.015) and enhanced flexibility. The rectus femoris muscle showed minor changes in biomechanical properties, with no statistically significant differences detected. Conclusions: Osteoarthritis significantly impacts muscle function, reducing the gluteus muscle tension and stiffness, which compromises joint stability and triggers compensatory activity in the rectus femoris and biceps femoris muscles. Postoperative rehabilitation is essential for improving flexibility and addressing compensatory muscle tension. [ABSTRACT FROM AUTHOR]

Introduction: MyotonPRO technology is a clinically accessible tool for objectively monitoring the biomechanical and viscoelastic properties of musculoskeletal tissues. This study aimed to identify the level of accuracy needed for recording from specified measurement sites on the soleus muscle and plantar fascia (PF), which are important for postural control and gait. Methods: In 20 healthy adults, MyotonPRO measurements were taken 1 cm above and below a standardized point on the soleus and PF. Ultrasound scans were also taken at each site to measure subcutaneous tissue thickness to aid interpretation of MyotonPRO findings. Results: Biomechanical and viscoelastic properties of the soleus and PF, measured using the MyotonPRO, were not affected by the change in the recording site. Subcutaneous tissue thickness above the PF changed significantly (p < 0.001) by 0.61 cm when moving distally by 2 cm, whilst above the soleus, these did not differ significantly (p = 0.175) when moving distally by 2 cm. Conclusion: Changing the recording site 1 cm above or below the standardized site did not affect either the MyotonPRO results (soleus and PF) or ultrasound results for soleus, whilst this same distance affected ultrasound measurements of subcutaneous tissue thickness above the PF significantly. Moving away from the musculoskeletal junction reduces the need for precision in relocating the recording site for measuring soleus. These findings allow for quicker and easier measurement of soleus or PF using the MyotonPRO. [ABSTRACT FROM AUTHOR]

Background: Biomechanical muscle properties, such as stiffness, can be valuable indicators of tissue health and show promise as a diagnostic and treatment measure for chronic low back pain (CLBP). The development of accessible assessment technologies, such as the MyotonPRO portable device, allows for the convenient quantification of muscle tone and stiffness changes. The aim of this study is to assess the reliability of lumbar erector spinae muscle stiffness with the MyotonPRO in healthy adults and to compare stiffness changes between prone and sitting position. Methods: Thirty asymptomatic participants (N = 15 women and N = 15 men) aged between 18 and 65 years were recruited to participate in this study. Two examiners tested muscle stiffness at the palpable muscle belly, one finger away from the spinous process at the level of the L4 vertebra, first from the left and then from the right side, both in prone position and after in sitting position. For inter-rater reliability, all participants were tested by two examiners on the same day, and intra-rater reliability was calculated using the same examiner's assessment results with an exact 24-h interval. Intraclass correlation coefficients (ICC), standard error measures (SEM) and minimum detectable change (MDC) with a 95% confidence interval were calculated to assess intra-rater and inter-rater reliability. Results: Statistical analysis revealed good intra-rater reliability with an ICC of 0.88 (95% CI [0.76–0.94]) for the stiffness of the left erector spinae and excellent intra-rater reliability with an ICC of 0.91 (95% CI [0.82–0.95]) for the right erector spinae, both in the prone position. Intra-rater reliability in the sitting position was excellent to very good with an ICC of 0.91 (95% CI [0.82–0.96]) for the left side and an ICC of 0.89 (95% CI [0.78–0.95]) for the right side. The results for the left-sided prone position showed good inter-rater reliability with an ICC of 0.87 (95% CI [0.73–0.94]). The prone position on the right side also showed good inter-rater reliability with an ICC of 0.84 (95% CI [0.68–0.92]). The inter-rater reliability for the left and right side in the sitting position was excellent with an ICC of 0.96 (95% CI [0.92–0.98]) for the left side and an ICC of 0.95 (95% CI [0.90–0.97]) for the right side. Conclusion: This study demonstrated high reliability in measuring lumbar erector spinae muscle stiffness with the MyotonPRO in healthy adults and the ability of the device to detect even small changes in erector spinae muscle stiffness, testing both the right and left sides and measuring in both prone and sitting positions. The use of the sitting position to assess lumbar tissue tension in individuals may serve as a valuable substitute for the prone position, particularly for patients who experience discomfort in the prone position, and could have additional practical significance in clinical settings. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate changes in muscle contractile properties during a training microcycle in semi-professional female football players and explore their relationship with training load variables. Nineteen players (age: 23.9 ± 3.9 years; body mass: 60.6 ± 6.9 kg; height: 164.5 ± 6.7 cm) underwent myotonometric assessments of the biceps femoris (BF) and rectus femoris (RF) before and after the following training sessions: MD1 (i.e., 1 day after the match), MD3, MD4, and MD5. Training loads were quantified for each session, revealing significant variations, with MD4 exhibiting the highest values for high-speed running distance, number of sprints, and accelerations. Notably, MD3 showed the highest perceived exertion (RPE), while MD5 recorded the lowest total distance run. Myotonometric assessments indicated significant differences in stiffness of the RF in MD3 and BF in MD5, as well as RF tone in MD5. The findings underscore a notable relationship between training load and myotometric variables, particularly in muscle stiffness and tone. These results emphasize the need for further research to clarify how training loads affect muscle properties in female athletes. [ABSTRACT FROM AUTHOR]

Introduction: Stiffness and length arewell-established tendon parameters in sports and medicine. Myotonometry and ultrasound imaging are the commonly used methods to quantify these parameters. However, further studies are needed to clarify the reliability of these methods, especially when assessing maximally loaded tendons and when conducted by different experienced investigators. This study aimed to determine the intra- and interrater reliabilities of measuring the stiffness and length of the patellar tendon (PT) and Achilles tendon (AT) using the myotonometry method and the extended field-of-view ultrasound (EFOV-US) technique at rest andmaximal load performed by different experienced investigators. Methods: Twenty-seven participantswere examined on three different days by one experienced investigator and one novice investigator. Primary outcomes were the intraclass correlation coefficient (ICC) and associated 95% confidence interval (95% CI), coefficient of variation (CV), standard error of measurement (SEM), and minimal detectable change (MDC) across the measurement days and investigators. Results: For PT measurements at rest and maximal load, the estimated ICCs for stiffness and length were ≥.867 and ≥.970, respectively, with 95% CIs ranging from poor (.306) to excellent (.973) and good (.897) to excellent (.999). The CV, SEM, and MDC for PT stiffness and length were ≤5.2% and ≤2.0%, ≤39.3 N/m and ≤0.9 mm, and ≤108.9 N/m and ≤2.6 mm, respectively. For AT measurements, some restrictions were evident for stiffness at rest and both parameters at maximal load. However, regarding AT length at rest, the estimated ICC was ≥.996, with an excellent 95% CI (.987-.999). The CV, SEM, and MDC for AT length at rest were 2.8%, ≤1.1 mm, and ≤2.9 mm, respectively. Conclusion: The estimated ICCs show good to excellent reliability for the myotonometry method and the EFOV-US technique for measuring PT stiffness and length at rest and maximal load for experienced and novice investigators. However, some restrictions are evident for the AT, especially for measurements at maximal load. [ABSTRACT FROM AUTHOR]

Background and Objectives: Muscle properties are critical for performance and injury risk, with changes occurring due to physical exertion, aging, and neurological conditions. The MyotonPro device offers a non-invasive method to comprehensively assess muscle biomechanical properties. This systematic review evaluates the reliability of MyotonPro across various muscles for diagnostic purposes. Materials and Methods: Following PRISMA guidelines, a comprehensive literature search was conducted in Medline (PubMed), Ovid (Med), Epistemonikos, Embase, Cochrane Library, Clinical trials.gov, and the WHO International Clinical Trials platform. Studies assessing the reliability of MyotonPro across different muscles were included. A methodological quality assessment was performed using established tools, and reviewers independently conducted data extraction. Statistical analysis involved summarizing intra-rater and inter-rater reliability measures across muscles. Results: A total of 48 studies assessing 31 muscles were included in the systematic review. The intra-rater and inter-rater reliability were consistently high for parameters such as frequency and stiffness in muscles of the lower and upper extremities, as well as other muscle groups. Despite methodological heterogeneity and limited data on specific parameters, MyotonPro demonstrated promising reliability for diagnostic purposes across diverse patient populations. Conclusions: The findings suggest the potential of MyotonPro in clinical assessments for accurate diagnosis, treatment planning, and monitoring of muscle properties. Further research is needed to address limitations and enhance the applicability of MyotonPro in clinical practice. Reliable muscle assessments are crucial for optimizing treatment outcomes and improving patient care in various healthcare settings. [ABSTRACT FROM AUTHOR]

Background: The investigation of soft tissue stiffness has garnered increasing interest due to its potential applications in detecting tissue conditions, monitoring therapy effects, and preventing sports injuries. This study utilized the MyotonPro as a reliable measurement device to assess muscle stiffness and muscle frequency in the vastus lateralis and medialis muscles of both the dominant and non-dominant legs. Methods: Sixteen young, healthy subjects (seven males and nine females, age 25 ± 3.46 years) participated in this study. To induce maximal muscle fatigue, the vastus lateralis and vastus medialis muscles were subjected to a 30 kg load using a single-leg leg press. Pre- and post-fatigue measurements were conducted by two testers on the dominant and non-dominant legs, respectively, employing the MyotonPro. Results: We revealed a significant increase in muscle stiffness after maximal muscle fatigue. Specifically, on the dominant side, the vastus lateralis exhibited a stiffness increase of 6.5%, while the vastus medialis showed a 6.3% increase. On the non-dominant side, the vastus lateralis demonstrated a 7.6% increase, and the vastus medialis exhibited a 6.7% increase in muscle stiffness. Furthermore, muscle frequency increased by 8.6% (vastus lateralis) and 13.5% (vastus medialis) on the dominant side and by 15.1% (vastus lateralis) and 6.3% (vastus medialis) on the non-dominant side. The reliability of the measurements varied, with Cronbach's alpha values ranging from inadequate 0.49 to very good 0.88. Conclusion: This study affirms the efficacy of the MyotonPro as a measurement device for assessing muscle stiffness and establishes its reliability. The observed increase in muscle stiffness after maximal muscle fatigue, accompanied by changes in muscle frequency, underscores the device's utility. However, further research is warranted to validate the reproducibility of these findings and explore additional facets of the muscular response to fatigue. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the effect of isometric prone trunk extension (IPTE) contraction intensity on the stiffness of erector spinae (ES), semitendinosus (ST), biceps femoris (BF), and gastrocnemius muscles to understand the overall muscle mechanical behavior during IPTE and to explore the mechanisms of oordinated contraction of the body kinetic chain. Methods: Twenty healthy females were recruited, and participants underwent IPTE at three contraction intensities, i.e., 0% maximum voluntary isometric contraction (MVIC), 30% MVIC, and 60% MVIC, and muscle stiffness was measured using MyotonPRO. Results: Muscle stiffness was moderately to strongly positively correlated with contraction intensity (r = 0.408-0.655, p < 0.001). The percentage increase in stiffness at low intensity was much greater in ES than in lower limb muscles and greater in ST and BF than in gastrocnemius, whereas at moderate intensity, the percentage increase in stiffness decreased in all muscles, and the percentage increase in stiffness in ES was lower than that in ST. There was a moderate to strong positive correlation between ES stiffness variation and ST (r = 0.758-0.902, p < 0.001), BF (r = 0.454-0.515, p < 0.05), MG (r = 0.643-0.652, p < 0.01), LG (r = 0.659-0.897, p < 0.01). Conclusion: IPTE significantly affected the stiffness of lumbar and lower limb muscles, and low-intensity IPTE activated the ES more efficiently. There were significant coordinated muscle contractions between ES, ST, and LG. This provides preliminary evidence for exploring the overall modulation pattern of the lumbar and lower limb muscles kinetic chains. In future studies, we will combine other stiffness assessment methods (such as Magnetic Resonance Elastography, Shear Wave Elastography, or electromyography) to corroborate our findings. [ABSTRACT FROM AUTHOR]

Context: The research on the change in properties of the lower leg muscles by different intensity sinusoidal vertical whole-body vibration ( SV - WBV ) exposures has not yet been investigated. Objective: The purpose of this study was to determine effect of a 20-minute different intensity SV-WBV application to the ankle plantar flexor and dorsiflexor muscles properties and hamstring flexibility. Design: Prospective preintervention -postintervention design. Setting: Physiotherapy department. Participants: A total of 50 recreationally active collegeaged individuals with no history of a lower leg injury volunteered. Interventions: The SV-WBV was applied throughout the session with an amplitude of 2 to 4 mm and a frequency of 25 Hz in moderate-intensity vibration group and 40 Hz in a vigorousintensity vibration group . Main Outcome Measures : The gastrocnemius and tibialis anterior muscle tone was assessed with MyotonPRO, and the strength evaluation was made on the same lower leg muscles using hand-held dynamometer. The sit and reach test was used for the lower leg flexibility evaluation. Results: The gastrocnemius muscle tone decreased on the right side (d = 0.643, P = .01) and increased on the left (d= 0.593, P = .04) when vigorous-intensity vibration was applied. Bilateral gastrocnemius muscle strength did not change in both groups (P >.05). Without differences between groups, bilateral tibialis anterior muscle strength increased in both groups (P < .01). B ilateral gastrocnemius and tibialis anterior muscle tone did not change in the moderate-intensity vibration group (P> .05). Flexibility increased in both groups (P < . 01 ); however, there was no statistically significant difference between the groups ( d = 0 . 169, P = . 55 ). Conclusions: According to study results, if SV-WBV is to be used in hamstring flexibility or ankle dorsiflexor muscle strengthening, both vibration exposures should be preferred. Different vibration programs could be proposed to increase ankle plantar Rexor muscle strength in the acute results. Vigorous-intensity vibration exposure is effective in altering ankle plantar flexor muscle tone, but it is important to be aware of the differences between the lower legs. [ABSTRACT FROM AUTHOR]

Muscle stiffness provides a key insight toward clinical assessment for rehabilitation. Regarding the high-cost and technical skill requirement of ultrasound shear wave elastography (SWE) restricting extensive clinical use, MyotonPRO has been proposed as a complementary tool for muscle stiffness measurement. There is a deficiency of studies revealing the use of this tool for measuring muscle stiffness contributing to hand control. The purpose of this study was to assess the capability and effectiveness of MyotonPRO and SWE for hand muscle stiffness characterization. The stiffness of the dominant flexor digitorum superficialis (FDS) muscle of 25 healthy participants (12 males and 13 females) aged 29.60 ± 9.81 years was evaluated while they performed grip tasks. The muscle stiffness of males and females was compared. The correlation between dynamic muscle stiffness given by MyotonPRO and Young's modulus obtained from SWE was investigated. Statistical analysis indicated a significant difference in the dynamic muscle stiffness between genders in all conditions (p < 0.05), whereas a significant difference in Young's modulus was found only at the resting state. A moderate correlation was found between dynamic muscle stiffness and Young's modulus (r ranged from 0.243 to 0.489). Therefore, MyotonPRO can be used to assess the muscle stiffness of the FDS muscle at rest and during muscle contraction. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Tissue Engineering Research / Zhongguo Zuzhi Gongcheng Yanjiu is the property of Chinese Journal of Tissue Engineering Research and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Microgravity induces spinal elongation and Low Back Pain (LBP) but the pathophysiology is unknown. Changes in paraspinal muscle viscoelastic properties may play a role. Dry Immersion (DI) is a ground-based microgravity analogue that induces changes in m. erector spinae superficial myofascial tissue tone within 2 h. This study sought to determine whether bilateral m. erector spinae tone, creep, and stiffness persist beyond 2 h; and if such changes correlate with DI-induced spinal elongation and/or LBP. Ten healthy males lay in the DI bath at the Institute of Biomedical Problems (Moscow, Russia) for 6 h. Bilateral lumbar (L1, L4) and thoracic (T11, T9) trunk myofascial tone, stiffness and creep (MyotonPRO), and subjective LBP (0- 10 NRS) were recorded before DI, after 1h, 6 h of DI, and 30min post. The non-standing spinal length was evaluated on the bath lifting platform using a bespoke stadiometer before and following DI. DI significantly modulated m. erector spinae viscoelastic properties at L4, L1, T11, and T9 with no effect of laterality. Bilateral tissue tone was significantly reduced after 1 and 6 h DI at L4, L1, T11, and T9 to a similar extent. Stiffness was also reduced by DI at 1 h but partially recovered at 6 h for L4, L1, and T11. Creep was increased by DI at 1 h, with partial recovery at 6 h, although only T11 was significant. All properties returned to baseline 30 min following DI. Significant spinal elongation (1.17 ± 0.20 cm) with mild (at 1 h) to moderate (at 6 h) LBP was induced, mainly in the upper lumbar and lower thoracic regions. Spinal length increases positively correlated (Rho = 0.847, p = 0.024) with middle thoracic (T9) tone reduction, but with no other stiffness or creep changes. Spinal length positively correlated (Rho = 0.557, p = 0.039) with Max LBP; LBP failed to correlate with any m. erector spinae measured parameters. The DI-induced bilateral m. erector spinae tone, creep, and stiffness changes persist beyond 2 h. Evidence of spinal elongation and LBP allows suggesting that the trunk myofascial tissue changes could play a role in LBP pathogenesis observed in real and simulated microgravity. Further study is warranted with longer duration DI, assessment of IVD geometry, and vertebral column stability. [ABSTRACT FROM AUTHOR]

The purposes of this study were to (1) examine the effects of different cervicothoracic postures on the stiffness of trapezius muscles and (2) compare the stiffness of the dominant and non-dominant trapezius muscles. Twenty-one healthy participants joined in this project. After maintaining different cervicothoracic postures for 2 min, MyotonPRO was used to measure the stiffness of the trapezius. The results showed that (1) the stiffness of trapezius muscles was significantly affected by different cervicothoracic postures. With the increase of neck flexion angle, the stiffness of the trapezius muscles increased (p < 0.05). The muscle stiffness of upper back relaxed was higher than that of upper back upright (p < 0.05). (2) The trapezius muscles on the non-dominant side were stiffer than that on the dominant side (p < 0.05). Poor cervicothoracic postures will increase the stiffness of upper, middle and lower trapezius muscles. Keeping the neck and upper back upright will keep the muscle stiffness at a low level, so as to reduce the occurrence of neck and shoulder fatigue and pain. [ABSTRACT FROM AUTHOR]

Background: There is still a lack of clinically practical device, which allows to perform rapid and accurate examination of the skin condition. For this reason, suitability of the MyotonPRO for the assessment of skin biomechanical and viscoelastic parameters was evaluated in this study. The aim of the study was to establish the reference values of five parameters measured by MyotonPRO various locations of human skin. Materials and methods: Oscillation frequency, dynamic stiffness, logarithmic decrement, mechanical stress relaxation and creep were measured at three different skin locations (clavicula, volar forearm and shin), using L‐shape short and medium arm probes in 32 young female volunteers. Mean values of obtained parameters recorded by both probes were compared among three skin locations while reliabilities of measurements were assessed. Additionally, relationships between all recorded parameters were examined Results: There were no statistically significant differences between the mean values of five measured parameters obtained with both probes in all investigated areas. However, statistically significant differences of mean values of almost all parameters measured among three places examined were found. Despite considerable differences in mean values of obtained parameters, there were visible strong correlations between some studied parameters in all three investigated areas of skin. Conclusion: It was demonstrated in all locations studied that the higher value of oscillation frequency corresponds to the higher value of dynamic stiffness, moreover such tissue recovers faster to its initial shape, and it was characterized by lower creep values. Such results indicate the existence of identical relationships between the same studied parameters in different areas of skin. [ABSTRACT FROM AUTHOR]

A decrease in muscle tone induced by space flight requires a standardized assessment of changes to control the state of the neuromuscular system. This study is a step toward the development of a unified protocol, aimed at determining the initial effect of the presence or withdrawal of support on muscle tone, the effects of a 2-h supportlessness in Dry Immersion (DI) experiments, and the changes in muscle tone depending on the site of measurement. To perform measurements of changes in muscle tone, we used a MyotonPRO device. The list of muscles that we assessed includes: trunk – mm. deltoideus posterior, trapezius, erector spinae; leg – mm. biceps femoris, rectus femoris, tibialis anterior, soleus, gastrocnemius; foot – m. flexor digitorum brevis, tendo Achillis, aponeurosis plantaris. The study involved 12 healthy volunteers (6 men, 6 women) without musculoskeletal disorders and aged 32.8 ± 1.6 years. At the start of DI, there was a significant decrease in muscle tone of the following muscles: mm. tibialis anterior (−10.9%), soleus (−9.6%), erector spinae (−14.4%), and the tendo Achillis (−15.3%). The decrease continued to intensify over the next 2 h. In contrast, the gastrocnemius muscle demonstrated an increase in muscle tone (+7.5%) 2 h after the start of DI compared to the immediate in-bath baseline. Muscle tone values were found to be site-dependent and varied in different projections of mm. erector spinae and soleus. In previous experiments, we observed a high sensitivity of the myotonometry technique, which was confirmed in this study. To make it possible to compare data from different studies, a standardized protocol for measuring muscle tone for general use in gravitational physiology needs to be developed. [ABSTRACT FROM AUTHOR]

Background: Stiffness of skin is widely used parameter in many research areas, for example cosmetic industry, dermatology or rheumatology for assessing of skin condition as well as changes occurring in skin. In this pioneering study, we conducted measurements of skin stiffness using MyotonPRO —novel tool, which was mainly used to evaluate biomechanical properties of muscles, ligaments and tendons. We expected that MyotonPRO , which shows great reproducibility in previous studies, will also be able to measure skin stiffness. Materials and methods: Four replaceable probes designed by MyotonPRO (L‐shape short and medium arm, standard cylindrical flat‐end probe and the same standard probe with disc attachment) were tested for measurement of skin stiffness in young women (30 healthy females) at three different locations (clavicula, volar forearm and shin). Results: There was no significant difference between stiffness values obtained with L‐shape short and L‐shape medium arm probes in all investigated areas. Stiffness values recorded by regular probe and regular probe with disc attachment differ significantly from those collected with L‐shape probes. There was also significant difference between values of stiffness obtained by standard with disc attachment and standard probes. Conclusion: Both L‐shape probes show a great reliability for skin stiffness assessment. Therefore, MyotonPRO can be considered a reliable device for assessing skin stiffness. [ABSTRACT FROM AUTHOR]

Copyright of Medical Science Pulse is the property of Public Higher Medical Professional School in Opole and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The objective of this study was to evaluate the reliability of four methods of assessing vastus lateralis (VL) stiffness, and to describe the influence of structural characteristics on them. The stiffness of the dominant lower-limb's VL was evaluated in 53 healthy participants (28.4 ± 9.1 years) with shear wave elastography (SWE), strain elastography (SE), myotonometry and tensiomyography (TMG). The SWE, SE and myotonometry were performed at 50%, and TMG was assessed at 30%, of the length from the upper pole of the patella to the greater trochanter. The thickness of the VL, adipose tissue and superficial connective tissue was also measured with ultrasound. Three repeated measurements were acquired to assess reliability, using intraclass correlation coefficients (ICC). Pearson's correlation coefficients were calculated to determine the relationships between methodologic assessments and between structural characteristics and stiffness assessments of the VL. Myotonometry (ICC = 0.93; 95%-CI = 0.89,0.96) and TMG (ICC = 0.89; 95%-CI = 0.82,0.94) showed excellent inter-day reliability whereas with SWE (ICC = 0.62; 95%-CI = 0.41,0.77) and SE (ICC = 0.71; 95%-CI = 0.57,0.81) reliability was moderate. Significant correlations were found between myotonometry and VL thickness (r = 0.361; p = 0.008), adipose tissue thickness (r = −0.459; p = 0.001) and superficial connective tissue thickness (r = 0.340; p = 0.013). Myotonometry and TMG showed the best reliability values, although myotonometry stiffness values were influenced by the structural variables of the supra-adjacent tissue. [ABSTRACT FROM AUTHOR]