###### Abstract  
The current study compared the effects of exercise program and a rehabilitation exercise program (REP) with electro muscle stimulation (EMS) on participants who had anterior cruciate ligament (ACL) reconstruction. The control group (CONG, \(n=12\)) and the electro muscle stimulation group (EMSG, \(n=12\)) were equally assigned among the 24 patients who underwent ACL reconstruction. For 12 weeks, CONG executed the REP, and EMSG executed of added EMS into the REP. Every participant in the rehabilitative exercise program completed two 60 min sessions each week for a total of 12 weeks. Both a pre- and post-evaluation were completed before and after the workout session. IKDC (International Knee Documentation Committee) score, Lysholm score, thigh circumference, muscular activity, and isokinetic muscle function were the variables examined. The EMSG exposed a significant increase (\(p<0.05\)) in Lysholm score, muscle circumference, muscle activity of vastus medialis (VM), rectus femoris (RM), and vastus lateralis (VL), and isokinetic function (peak torque, total work). However, CONG only showed a significant increase in IKDC score (\(p<0.05\)). This study proved that the REP employing EMS following ACL reconstruction enhanced muscular activation during muscle contraction when compared to REP, and it showed that using EMS in rehabilitation exercise is an effective rehabilitation strategy. a 2023  
muscle since it reduces one's capacity to walk normally and their ability to maintain their postural stability [4]. The quadriceps femoris muscle weakening following ACL reconstruction is causing this issue [5]. [PERSON] et al. [6] reported quadriceps muscle mass weakness by 20-30% during the about 3 months after ACL reconstruction and [PERSON] et al. [7] reported that quadriceps femoris muscle weakness after ACL reconstruction can persist for 1 year after 6 months of rehabilitation exercise program. According to these previous studies, regaining quadriceps muscle function--including strength, endurance, and power--is crucial for restoring knee function following ACL surgery and for successfully returning to everyday activities or athletics [8]. Due to knee pain, edema, swelling, and fear of re-injury, which might result in muscle atrophy and loss, functional motions may be limited who have undergone ACL reconstruction [9]. Therefore, previous studies related to rehabilitation after ACL reconstruction recommend that the rehabilitation exercise program be applied in the early stage after surgery [10]. However, the traditional rehabilitation exercise program for initial muscle function recovery after ACL reconstruction causes pain due to anthropogenic muscle inhibition and limitation of the joint ROM, and so, there are many difficulties in recovering muscle strength, endurance, and power [11]. In recent studies, rehabilitation exercise programs using electro muscle stimulation (EMS) were widely used to not only relieve pain but also to solve problems of muscle atrophy and decreased muscle function [12]. EMS is an effective way in which electrical pulses delivered to muscles through electrodes placed on the skin stimulate motor nerves to induce muscle contraction and generate functionally useful movements through electrical stimulation, which can generate large forces with minimal neuromuscular fatigue. Therefore, it is an effectively used tool for muscle recovery and rehabilitation exercise [13; 14]. Various previous studies reported the recovery of the muscle function using EMS rehabilitation exercise program; however, the EMS stimulation frequency used for the recovery of muscle function are different [14; 15; 16]. Current parameters, which are important determinants, such current amplitude, pulse length, and frequency must be adjusted to produce the EMS effect. In addition, surface electrode properties such as size, type, and location should be considered [17]. [PERSON] et al. [15] reported that 50 Hz stimulation frequency was most effective in restoring muscle function using EMS; however, [PERSON] et al.