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IntroductionThis study aimed to establish normative values for stiffness, tone, and elasticity of lower extremity muscles and to determine age and sex differences.MethodsOverall, 389 participants (199 females, 190 males) were included. The mechanical properties of the tibialis anterior (TA), rectus femoris (RF), vastus lateralis (VL), vastus medialis obliquus (VMO), gastrocnemius lateralis (GL), and gastrocnemius medialis (GM) muscles were assessed bilaterally with the MyotonPRO device. The data were compared with respect to sex and age.ResultsThe mechanical properties were significantly higher bilaterally in males than females in all parameters (<i>p</i> < 0.05). Right TA stiffness and elasticity, GM tone and stiffness were higher than left in females (<i>p</i> < 0.05). Greater VMO elasticity and RF tone were found in left vs. right (<i>p</i> < 0.05). Right GL-VL stiffness and elasticity were greater than left in males (<i>p</i> < 0.05). VMO-RF tones were bigger in left compared with right (<i>p</i> < 0.05). Among age groups, right-left TA tone and stiffness were greater in group 1 (18–28 years old) (<i>p</i> < 0.05). Right-left VL-VMO tones, and left RF stiffness and tone were lower in group 2 (29–39 years old) (<i>p</i> < 0.05). Right GM-VMO stiffness, right-left TA-GL-GM-VMO and RF elasticity were greater in group 3 (40–50 years old) compared with others (<i>p</i> < 0.05).ConclusionsThe mechanical properties of leg muscles were bilaterally higher in males. Different characteristics were observed of different muscles for both sexes. GL-GM-VMO-RF elasticity decreased, and TA stiffness and VMO tone increased with advancing age in both legs

Background: The body mass index (BMI) is closely related to fat tissue, which may have direct or indirect effects on muscle function. Previous studies have evaluated BMI and muscle viscoelastic properties in vivo in older people or individual sexes; however, the relationship between BMI and muscular viscoelastic properties is still unknown. Aims: The purpose of this study was to determine the correlation of BMI with muscular viscoelastic properties, and to compare these properties in a young sedentary population with normal and overweight individuals. Methods: A total of 172 healthy sedentary individuals (mean age, 26.00 ± 5.45 years) were categorized by sex (male and female) and BMI classification (normal (BMI, 18.50–24.99 kg/m2), overweight (BMI = 25.00–29.99 kg/m2)). Body weight was evaluated using an electronic scale, while height was measured using a standard stadiometer. BMI was calculated by dividing the weight in kilograms by the square of height in meters. The viscoelastic properties (tone, stiffness, and elasticity) of the biceps brachii (BB) and biceps femoris (BF) muscles were measured bilaterally using the MyotonPRO device at rest. Results: The bilateral BF tone and stiffness, right BB stiffness, and elasticity showed weak correlations with BMI in all participants. Furthermore, the bilateral BF tone and stiffness, right BB stiffness and elasticity, and left BB stiffness were weakly positively correlated with male sex. Only the right BB elasticity was weakly positively correlated with BMI in females (p < 0.05). No correlation with BMI was determined for other viscoelastic properties (p > 0.05). The overweight group showed increased bilateral BF stiffness and tone, right BB stiffness, and reduced bilateral BB elasticity compared to the normal-weight group (p < 0.05), while other viscoelastic properties were similar (p > 0.05). Greater bilateral BB tone, BF tone and stiffness, and lower BF elasticity were observed in males than in females (p < 0.05), but other viscoelastic properties were not significantly different (p < 0.05). No effect of BMI–sex interactions was found on viscoelastic properties (p > 0.05). Conclusions: The BB and BF viscoelastic properties were weakly correlated with BMI. Males showed greater muscle tone and stiffness, and lower elasticity. The overweight individuals showed increased stiffness and tone, particularly in lower extremities, and reduced elasticity in upper extremities. The effect of BMI–sex interactions on the viscoelastic properties was not clear. Higher BMI (increased mechanical load) might cause the human body to develop different muscular viscoelastic adaptations in the extremities.

Background: The study was to determine influence of body mass index on muscular mechanical properties in people with obesity.Methods: A total of 172 participants (86 males and females, mean age; 26.00±5.45 years) were participated. The participants were assigned in groups base on BMI classification (normal (BMI=18.50-24.99 kg/m2), overweight (BMI=25.00-29.99 kg/m2). The biceps brachii (BB), biceps femoris (BF) were measured bilaterally using the "MyotonPRO" device. Results: Bilateral BB and BF stiffness, and BB elasticity were found significantly difference between normal and overweight group in all participant comprasion (p<0.05). Also the only left BB tone was found different (p<0.05) while other mechanical parameters found similar (p>0.05). In sex based BMI sub-categories; the bilaterally BB and BF stiffness and BF tone were found higher, and only the right BB elasticity was decreased in overweight male group (p<0.05). While the other mechanical parameters were found similar (p<0.05). The right BB stiffness and elasticity were found higher in overweight female group (p<0.05). No statistical difference was found in other parameters for female comparison (p>0.05).A weak positive correlation was found between the right-left BB tone and stiffness and BMI. Also, a weak positive correlation was revealed between the right BB elasticity (p<0.05). No correlation was determined in other mechanical paramaters (p>0.05).Conclusions: The bilateral BB and BF stiffness increased and BB elasticity decreased as BMI increased. The BB and BF mechanical properties were affected more in males than females when BMI considered.

Objective: To examine the age-related changes in the viscoelastic properties and tone of the superior orbicularis oris muscle by a portablehand-held myotonometer. Methods: A total of 128 individuals (65 female, 63 male) who met the inclusion criteria were evaluated. Individuals were divided into 2 groups as under 40 years old (Group 1), and above (Group 2). The viscoelastic properties and muscle tone of orbicularis oris muscle were evaluated bilaterally in supine position with the Myoton PRO (Myoton AS, Estonia) device from the skin overlying the orbicularis oris. The reference point is accepted as the right and left paramedial philtrum dimple. The statistical analysis was performed.Results: There was no statistically significant difference in the elasticity values of the right and left orbicularis oris muscles of the Group 1 and Group 2 individuals. There was a difference between the groups when the tone and stiffness values of both groups were compared. It was determined that individuals over the age of 40 had higher muscle tone and stiffness. All mechanical properties of the superior orbicularis oris muscle between the male and female individuals in Group 1 were different. The values are higher in the female gender. The elasticity values in both genders in Group 2 were similar. Tone and stiffness parameters were different between genders. Conclusions: Myoton PRO can be recommended as an alternative device in the quantitative evaluations of post-operative follow-ups, and pre/post rehabilitation in terms of viscoelastic parameters of the muscle.