An Investigation of Reflex elicited by Percutaneous Stimulation of the Medial and Dateral Ligaments of the Knee

The principal purpose of this study is to extend our knowledge of reflexes associated with the joint. disease and injury of joints are major causes of pain and disability in the population. surprisingly, there have been very few neurophysiological studies of the reflex effects associated with stimulation of joints, ligaments and tendons. similar experiments have been performed in humans and the existence of reflexes has been confirmed. the immediate aim of this project is,to investigate reflexes elicited by percutaneous stimulation of the medial and lateral ligaments of the knee, during standing, walking and running. this approach allows natural movements to take place and so the reflexes can be studied in a much more natural context. the longer-term aim is to provide a strong scientific foundation, which will guide the coaching of athletes to reduce the risk of joint injury and to enhance the rehabilitation of athletes after injury. thirteen subjects were seated on a testing bench and hip angle was 90 degrees. the age range of the subjects was from 21 to 48 years. they were instructed to exert 5, 10 and 20% of maximal isometric voluntary effort in knee extension it for 50 seconds. electrodes were placed over the lateral and medial knee ligaments separately and the ligaments were stimulated by 3 pulses of 1 msec duration at 100 hz. the range of miliamper was 0-40ma. i was looking to record reflexes between 40 to 100ms,because most activities before this time (40ms) are artifact movements and after 100ms are more complex non segmental muscle reflexes. the emg activity from three muscles was monitored simultaneously using surface electromy-ography by 1401 electromyogram, and for data analysis used to spike2 software system. the muscles selected were rectus femoris, vastus medialis and vastus lateralis. electrodes were placed over the muscles. skin was mildly abraded and then cleaned with an alcohol wipe. five of 13 subjects have not any reflex at any current. four subjects just have one reflex in high current intensity. four subjects have reflex in low and high currents. there is no effect in very low current, effects have started in 15 ma. also the reflexes have been bigger when current has increased. we recorded inhibition and excitation reflexes and there is no significant difference between medial and lateral ligament stimulation but mostly effects are inhibition in both ligaments. some of the subjects have no reflexes, on the other hand some subjects have strong reflexes.