## 3 Results  
Twenty-five healthy participants (12 males and 13 females) with ages of 29.60 \(\pm\) 9.81 years, height 1.69 \(\pm\) 0.09 m, weight 65.85 \(\pm\) 14.76 kg, and BMI 22.65 \(\pm\) 3.53 kg/m\({}^{2}\) participated in the study. The demographics of the participants are shown in Table 1.  
From the SWE measurements, elasticity maps of the FDS muscle in different intensities of muscle contraction are shown in Figure 2. For males, the mean [PERSON]'s modulus of the resting state (0%MVC) was 35.86 \(\pm\) 8.74 kPa. When grasping intensity was changed to 20%, 40%, 60% and 80%MVC, there was an alteration in the level of muscle activation; mean [PERSON]'s modulus was 55.92 \(\pm\) 14.73, 70.00 \(\pm\) 11.81, 85.15 \(\pm\) 18.95 and 103.79 \(\pm\) 17.76 kPa, respectively. In the case of females, the mean [PERSON]'s modulus of the resting state (0%MVC) was 27.47 \(\pm\) 5.59 kPa. When grasping intensity increased to 20%, 40%, 60%MVC and 80%MVC, the mean [PERSON]'s modulus was 47.91 \(\pm\) 16.76, 63.16 \(\pm\) 19.26, 80.82 \(\pm\) 19.67 and 102.39 \(\pm\) 20.36 kPa, respectively. The results of this study revealed that the mean [PERSON]'s modulus for different intensities of muscle contraction in males was significantly higher than in females (Table 2). The statistical analyses indicated that there were significant differences (\(p\) < 0.05) between the mean [PERSON]'s modulus of males and females at only 0%MVC. However, there were no significant differences in the muscle elasticity at 20%, 40%, 60% and 80%MVC (Figure 3). From the MyotonPRO measurements, the results of this study revealed that the mean dynamic muscle stiffness in different intensities of muscle contraction in males was significantly higher than in females, as shown in Table 2. For males, the mean resting dynamic muscle stiffness (0%MVC) was 355.46 \(\pm\) 26.07 kPa. When muscle activation increased to 20%, 40%, 60% and 80%MVC, the mean dynamic muscle stiffness also increased to 442.96 \(\pm\) 50.12, 522.58 \(\pm\) 53.04, 566.63 \(\pm\) 62.74 and 603.63 \(\pm\) 70.70 kPa, respectively. For females, the mean resting dynamic muscle stiffness (0%MVC) was 303.54 \(\pm\) 45.66 kPa. When the intensity of grasping increased to 20%, 40%, 60% and 80%MVC, the mean dynamic muscle stiffness was 371.12 \(\pm\) 57.99, 398.81 \(\pm\) 138.15, 464.69 \(\pm\) 90.46 and 497.73 \(\pm\) 98.25 kPa, respectively. The statistical analyses indicated that there were significant differences (\(p\) < 0.05) between the mean dynamic muscle stiffness of males and females at all different intensities of muscle contraction (Figure 4). \begin{table}
\begin{tabular}{l l l l l} \hline  & **Total (\(n\) = 25)** & **Males (\(n\) = 12)** & **Females (\(n\) = 13)** & \(p\)**-Value** \\ \hline Age (years) & 29.60 \(\pm\) 9.81 & 27.92 \(\pm\) 5.53 & 31.15 \(\pm\) 12.73 & 0.017 * \\ Weight (kg) & 65.85 \(\pm\) 14.76 & 73.67 \(\pm\) 14.62 & 58.63 \(\pm\) 11.04 & 0.915 \\ Height (m) & 1.69 \(\pm\) 0.10 & 1.76 \(\pm\) 0.07 & 1.62 \(\pm\) 0.06 & 0.101 \\ BMI (kg/m\({}^{2}\)) & 22.95 \(\pm\) 3.53 & 23.61 \(\pm\) 3.35 & 22.34 \(\pm\) 3.71 & 0.899 \\ \hline \end{tabular}
\end{table} 
Table 1: General characteristic of participants. Figure 2: Representative shear wave elastography image for the evaluation of flexor digitorum superficialis (FDS) muscle stiffness in different intensities of muscle contraction. **(A,B)** Motion (particle velocity in an axial direction) distribution at T1 and T2, respectively. **(C)** Structural image shows the target layer of the FDS muscle. **(D–H)** Elasticity map in the muscle at 0%, 20%, 40%, 60% and 80%MVC, respectively. The result revealed that muscle stiffness increases at higher intensity of muscle contraction. Figure 4: Mean dynamic muscle stiffness of the flexor digitorum superficialis (FDS) muscle at different intensities of muscle contraction.