Fig. 4

In this figure, R20-1 represents the rate of change in the displacement of the nerve root inside the spinal canal caused by increasing the load from 50 g (one weight) to 1000 g (20 weights). R40-20 represents the rate of change caused by increasing the load from 1000 g (20 weight) to 2000 g (40 weights). R60-40 represents the rate of change caused by increasing the load from 2000 g (40 weight) to 3000 g (60 weights). In the figure, we can see that the rate of change in the displacement of the C6 nerve roots inside the spinal canal is the smallest under each load, followed by those of the C5, C7, and C8 nerve roots, which were relatively high