The diagnostic value of H-index in S1 root compression

The H-index was studied in 42 healthy subjects and in 20 patients showing unilateral S1 root compression. When compared to the normal subjects, all patients showed a decreased H-index, or an increased difference in H-index between the sides or both. These results indicate that both parameters are valuable in the diagnosis of S1 root impairment due to intervertebral disc protrusion.