To begin, cut the skin of an anesthetized rabbit below the patella, following the length of the limb upwards to the thigh base, then continue upwards for three to four centimeters. Carefully peel off the skin and fascia, exposing the quadriceps muscle. Cut the patellar ligament and carefully separate the quadriceps from the iliac junction, while maintaining the quadriceps in connection with the ilicium.
Now ligate the surgical sutures at the tendon junction between the patella and quadriceps muscle. Stretch the muscle to its full length in its natural state and attach it to the tension transducer, aligning the ligation line on the muscle with that on the transducer. Secure the tension transducer to the bracket.
Connect the signal acquisition line on the transducer to the bio signal acquisition system processor. Insert the electrodes parallel to the quadriceps abdomen, avoiding contact between the electrodes. Next, press the oscilloscope button.
Adjust the position of the force transducer on the bracket to maintain the baseline at zero. At this stage, set the stimulator stimulation parameters with a single stimulus, a wave width of five milliseconds and a delay of 10 milliseconds. Set the initial value of the stimulus amplitude to zero volt and set the automatic amplitude to increase by 0.1 volt each time, to gradually increase the stimulus intensity.
Then start the stimulation while observing the changes in the muscle contractions curve and contraction amplitude, until the maximum signal twitch amplitude of the quadriceps is determined. Next, use a cluster stimulus and set the stimulus amplitude, causing a maximum single twitch as the baseline to continuously stimulate the muscle. Set the initial value of the stimulation frequency to 10 hertz, and set the automatic frequency to increase by one hertz each time to gradually increase the stimulus frequency.
Finally, start the stimulation while observing the changes in the muscle contraction curve until the maximum tetanic contraction amplitude of the quadriceps is determined. Young's modulus, single contraction amplitude, and tetanic contraction amplitude of the quadriceps femoris were significantly reduced in knee osteoarthritis group compared to the control and Acupotomy group.
