The second student then slides the reflex hammer along the meter stick until it strikes the area below the knee. This is done to reduce the error from any twisting motion that would increase torque and velocity. Students view their strikes using the video tape player's single frame advance and counting the number of frames required to move the hammer to the knee. Each frame is 33 ms in length and this value could be quantified as a time or the number of frames can be used as a relative measurement. This data is recorded in a data table.
Students also measure the movement of the foot.
There are several approaches to make this measurement. One suggestion is to count how high the foot travels using the toe as a reference. Other measurement strategies may use complete range of movement or speed, etc. 11. The data are graphed. Figure 1 .