This study looked at a very interesting idea. Who should get traction? The results were clear:
Musculoskelet Sci Pract. 2017 Oct;31:1-8.
Static traction was associated with an increase in diffusion of water within the L5-S1 IVDs of middle-age individuals, but not in young adults, suggesting age-related differences in the diffusion response. Further study is needed to assess the relationship between these findings and the symptoms of back pain.