The aim of this study was to investigate the effects of acupuncture to SP 3 on the quadriceps femoris during knee extension in patients with musculoskeletal diseases by applying the meridian concept.
The subjects included 10 healthy individuals with a mean age of 23.1 years, and all of whom provided informed consent for participation. During knee extension, each subject underwent three different types of acupuncture stimuli : 1) stimulation to SP 3, 2) stimulation to SP 4, and 3) no stimulation. For each stimulation,the subjects performed isometric contraction with 40% of maximum voluntary contraction with knee flexion to 60°. Surface electromyography (EMG) of the vastus medialis obliquus, vastus medialis longus, rectus femoris,and the four sites within the vastus lateralis was performed during knee extension before acupuncture stimulation ; immediately after starting stimulation ; and 5, 10, and 15 min after starting stimulation. Relative-integrated EMG data was recorded during and after acupuncture stimulation and compared to data that were recorded before acupuncture as reference values.
The results showed that after 15 min of acupuncture stimulation to SP 3, the relative-integrated EMG data on the vastus medialis obliquus was significantly increased compared to the data obtained without stimulation (p < 0.05).
Therefore, in conclusion, after 15 min of acupuncture stimulation to SP 3, the relative-integrated EMG data on the vastus medialis obliquus exhibited suppressed muscle function.