[Acute effects of mechanical lumbar traction with different intensities on stature]

to compare the efficacy of mechanical lumbar traction with low (10% of body weight) and high traction force (50% of body weight) on the separation of the vertebrae in vivo using stature variations as criterion. Additionally, we aimed to determine the time that the effects of traction last.

Thirty apparently healthy subjects (age: 20.9 ± 1.7 years old), 14 male and 16 female, were submitted to two protocols of 15 minutes of continuous traction (with intensity of 10% and 50% of body weight), in two sessions one week apart. The protocol order was determined randomly. Stature was assessed before and immediately after the traction and every five minutes for 30 minutes after traction ceased.

Immediately after the traction both protocols induced a significant increase in stature, however the magnitude of the increase was significantly superior in the traction with 50% of body weight (0.567 ± 0.049 vs. 0.298 ± 0.041 cm, p>0.001). After the traction with 50% of body weight the increase in the stature was maintained until ten minutes after the end of the traction, while after the traction with 10% of body weight the effects on stature disappeared after five minutes.

The mechanical vertebral traction of the lumbar region performed continuously with 50% of body weight during 15 minutes induced an increase in stature superior and longer in time than that observed with a traction force of 10% of body weight.