Active_comparator: conventional physiotherapy

Demographic and medical information of the patients (age, gender, height and body weight, occupation, educational status, CV, family history and surgical history, medical history related to knee osteoarthritis) and pain level will be questioned. Conventional physiotherapy modalities will be applied in the group; exercise training, hotpack, ultrasound and transcutaneous electrical nerve stimulation (TENS). Patients will be treated for one hour, three days a week, for eight weeks.~The physical functions, muscle structure and knee joint cartilage thickness, quality of life and functional status of the patients will be evaluated before and after treatment.

Active_comparator: NMES

Demographic and medical information of the patients (age, gender, height and body weight, occupation, educational status, CV, family history and surgical history, medical history related to knee osteoarthritis) and pain level will be questioned. In addition to conventional physiotherapy methods, passive NMES treatment will be applied in the group.Patients will be treated for one hour, three days a week, for eight weeks.~The physical functions, muscle structure and knee joint cartilage thickness, quality of life and functional status of the patients will be evaluated before and after treatment.

Active_comparator: superimposed NMES

Demographic and medical information of the patients (age, gender, height and body weight, occupation, educational status, CV, family history and surgical history, medical history related to knee osteoarthritis) and pain level will be questioned. In addition to conventional physiotherapy methods, superimposed NMES treatment will be applied in the group. Patients will be treated for one hour, three days a week, for eight weeks.~The physical functions, muscle structure and knee joint cartilage thickness, quality of life and functional status of the patients will be evaluated before and after treatment.