A Study of Dependence in the Patellar-Tendon-Reflex on Tapping Locations

The present study investigates the changes in the interaction between the tapping-force and the resulting angular-speed of the knee as the impact location is varied. The tapping force is measured with a force sensor mounted on the hammer and the resulting angular speed of the knee joint is calculated using the data obtained with a tri-axial accelerometer fixed at the ankle of the human subject. From the data taken at six different spots on the tendon location, which are separated vertically with an equal distance, it is concluded that the upper-area of tendon (UAT) and center-area of tendon (CAT) areas are suited for eliciting tendon reflex. This result has long been known by many medical doctors from experiences, without scientific proof. Such information is useful in the design of the patellar-tendon-reflex simulator, which assimilates the lower-leg motion in response to the tapping force applied at the load that acts as a human tendon.