Tackle direction and preferred side affect upper body loads and movements in rugby union tackling

Tackling in Rugby Union is associated with most match injuries. New tackle regulations have been explored to reduce injuries, but limited quantitative evidence is available to inform any law changes. Using a novel tackle simulator, we investigated upper body loading under different tackling conditions: direction of approach (0 degrees - frontal, 45 degrees and 90 degrees to the ball carrier direction) and side of body (dominant vs. non-dominant). Peak impact force between tackler and simulator , and head and upper trunk segment motions were measured from 10 male players. Impact load averages were 17% higher at (0 degrees) compared with (90 degrees), across the two different tackling sides (p = 0.093), with the highest impact force measured during dominant-side shoulder tackles at 0 degrees (5.63 +/- 1.14 kN). Trunk resultant accelerations were higher (+19%, p = 0.010) at 0 degrees compared with 90 degrees, with the highest resultant acceleration measured in frontal tackles with the dominant shoulder (17.52 +/- 3.97 g). We observed higher head lateral bending around the impact when tackling with the non-dominant shoulder at 45 degrees (p = 0.024) and 90 degrees (p = 0.047). Tackling from an offset angle from frontal may be safer. Deficiencies in tackling techniques on the non-dominant side should be reduced.

Automated summary

Tackling in Rugby Union is associated with most match injuries, and new tackle regulations have been explored to reduce injuries, but limited quantitative evidence is available to inform any law changes. Using a novel tackle simulator, this study investigated upper body loading under different tackling conditions and found that impact load averages were higher at 0 degrees frontal approach compared with 90 degrees, with the highest impact force measured during dominant-side shoulder tackles at 0 degrees. Trunk resultant accelerations were also higher at 0 degrees compared with 90 degrees, and higher head lateral bending was observed when tackling with the non-dominant shoulder at 45 degrees and 90 degrees.