## 4 Discussion
Study [7] showed that the median nerve is stressed due to mechanical contact with the surrounding tissues, not due to fluid. Normally, without opening the carpal tunnel, the fluid fills the free cavities or is absorbed by the tissues. Thus, hydrostatic pressure may be one of the indirect indicators of compression. The geometry used in this study is based on CT and MR images of a healthy person without carpal tunnel syndrome. Obviously, the median nerve of a healthy person should not be squeezed excessively, especially considering the small external load. However, using this model, it is possible to estimate the influence of various mechanical factors on the compression of the median nerve [5]. An increase in the median nerve or tendon cross-section will increase the load on the median nerve. The close proximity of the tendons and median nerve will also increase the load on the median nerve. These may also be subjects for further research. The choice of contact interaction between the median nerve and the SACT can influence the results of the study. This study used no separation connections. Tendon anatomy is arranged in such a way that their tension pulls the SACT away from the median nerve. The median nerve stretches or compresses depending on the movement of the tendon. The model developed in this study accounts for the effect of each tendon separately, while this is not possible with tests similar to the Phalen test or any other tests. Among all four cases of motion considered in this paper, it was possible to identify some important mechanical features that characterize the corresponding motion. The most important characteristic is the rate of median nerve compression depending on the type of movement, because when the angle of rotation of the corresponding phalanges increases, this rate is expected to remain unchanged. Then, the maximum compression corresponds to the maximum compression rate obtained in this study. Calculations revealed the highest compression rate for wrist flexion. Nevertheless, other significant factors were observed. For example, the distribution of pressure between the median nerve, SACT, and transverse ligament during different movements showed that during finger flexion the median nerve takes up to 30% of the load, while during other movements less than 10%. However, the actual stress was less than that of wrist flexion. Thus, the most traumatic movement of the studied in this work was wrist flexion, but taking into account the external load can affect this result. For example, loading the distal phalanges can greatly increase compression of the median nerve, and if it is considered that the median nerve takes up to 30% of the wrist canal load when flexing the fingers, the resultant pressure on the median nerve can be greater than when flexing the wrist. \begin{table}
\begin{tabular}{c c} \hline \hline
**Study** & **Carpal Tunnel Pressure [Pa]** \\ \hline [PERSON] et al. [26] & 266 \\ [PERSON] et. el. [28] & 100–300 \\ [PERSON] et al. [30] & 106–360 \\ \hline Our results & 197–227 \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Comparison of experimental results with the results obtained using the finite element method. The importance of modeling the entire finger system (phalanges, tendons, and annular ligaments) is evident in this study. Finger flexion changes the geometry of the tendons, and this geometry greatly affects SSCT movement [32]. Mechanical parameters of the SSCT are lower than those of the tendons (Table 1) [23]. The tendons barely change their shape while sliding along the carpal tunnel. However, flexion of the finger changes the shape of the tendons. Without taking into account wrist and finger movement, it is impossible to simulate the external load caused by tendon movement. Sometimes median nerve overload can be caused not only by the tendon, but also by an external load on the transverse ligament [33]. These mechanical factors together can greatly increase nerve compression.