## 4 Discussion
[33] reported changes in femoral muscle strength reported that neuromuscular electrical stimulation was applied to soccer players that underwent anterior cruciate ligament surgery for four weeks, three days a week, three times a day, and 30 times a day. When applied as a program of 10 s muscle contraction, 50 s rest at a frequency of 50 Hz per minute, they reported significant improvements in quadriceps muscle strength and thigh circumference compared to controls. Similar outcomes were found in this investigation, although the quadriceps muscle's isometric muscular strength function in the fully extended condition did not demonstrate a significant improvement in the VM muscle, but the VM muscle's isokinetic muscle strength function did. This is connected to the fact that during open chain exercise (OKC), the vastus medialis muscle operates primarily on medial stability of the patella at the about 10-15\({}^{\circ}\) of knee joint [34]. Moreover, it was noted that during knee extension, the vastus medialis muscle (VM) had greater muscular activity than the vastus lateralis muscle (VL) [35]. According to [PERSON] et al. [36] the vastus medialis (VM) showed a significant level of muscle activity when the knee was completely flexed between 60 and 90\({}^{\circ}\), and a low level of activity when the knee was completely extended. Therefore, we found that more significant muscle activity occurred during more knee-extension movements in the full knee condition, and EMS exercise in particular is reported to increase muscle activity. The present study revealed increased PT and TW in all groups after 12 weeks compared to pre-exercise, with the EMSG showing a significantly higher rate of increase in PT and TW than the CONG. According to [PERSON] et al. [37] a 6-week EMS exercise program enhanced maximal muscular strength much more than the normal exercise group. [PERSON] et al. [38] discovered a slight but significant difference in the PT of lower limb muscular strength following the 10-week EMS training program. This was consistent with our study. Reviewing the results of such previous research and this experiment, it was concluded that an EMS exercise program of 6 weeks or longer has a positive effect on muscle function improvement. A previous study also reported that EMS was an efficient modality that elicited substantial improvements in isokinetic muscle function [39], suggesting that following ACL reconstruction, EMS paired with regular exercise will be an effective method for improving isokinetic muscle function within 4 weeks [40]. [PERSON] et al. [41] reported that treatment of EMS for three weeks reduced atrophy of type II fibers and maintained preserved contractility of type I fibers to increase and, maintain contractile velocity and power output of muscle. As such, it is judged that the combined treatment of EMS and other dynamic exercises (e.g., plyometrics, sprints, vertical jumps) to improve muscle function in ACL patients can induce more muscle contractions. In addition, it is considered to be effective in that more fast-twitch fibers muscle are mobilized during muscle contraction, which helps to improve muscle hypertrophy and function. Therefore,it is determined that in order to increase voluntary muscular strength and anaerobic power output, future research should concentrate on the long-term effects of EMS dynamic contraction and the best way to combine EMS with dynamic training modalities. [PERSON] et al. [42] reported that performing EMS training at least 4 weeks and two to four times a week, at a frequency 20 to 70 Hz is effective for muscle nerve improvement, and should be performed at a frequency above 50 Hz, and for at least 9 weeks, to induce effects on functional parameters such as walking. It was also said to be beneficial for improving muscle form changes and functions when employing appropriate frequencies and pulse widths, and typically calls for pulses of 100-400 \(\upmu\)s, frequencies of 50-100 Hz, and contractions of 5-10 s [20; 43].