Relationships Between Hex Bar Deadlift One-Repetition Maximum and Maximal Isometric Pulls

Area of Science:

• Biomechanics
• Strength and Conditioning
• Human Movement Science

Background:

• The hexagonal barbell deadlift (HBB) is a popular strength exercise.
• Understanding the relationship between isometric strength and dynamic lifting capacity is crucial for optimizing training.
• Maximal isometric pulls assess force production at specific joint angles.

Purpose of the Study:

• To investigate the correlation between hexagonal barbell deadlift one-repetition maximum (1-RM) and force-time characteristics during maximal isometric pulls.
• To identify isometric pull positions that best predict maximal deadlift strength.

Main Methods:

• Twenty-three healthy adults performed HBB deadlift 1-RM tests and maximal isometric pulls at lift-off (FLOOR), knee-passing (KNEE), and mid-thigh (MT) positions.
• Force-time data, including peak force (PF), time-specific force, rate of force development (RFD), and impulse, were analyzed.
• Correlation analyses were used to determine relationships between 1-RM and isometric force-time variables.

Main Results:

• Strong to very strong correlations were found between 1-RM and peak force (r = 0.695-0.879), time-specific force (r = 0.506-0.812), and impulse (r = 0.575-0.778) across all positions.
• Moderate to very strong relationships were observed for rate of force development (RFD) time-bands (r = 0.430-0.752).
• Peak force at the FLOOR and KNEE positions demonstrated the strongest predictive relationship with 1-RM HBB deadlift strength.

Conclusions:

• Isometric pulls, especially from the lift-off and knee-passing positions, are significant predictors of maximal hexagonal barbell deadlift strength.
• These findings suggest that incorporating isometric pulls at these specific positions may enhance training for maximal strength.
• The isometric mid-thigh pull position showed weaker correlations, potentially due to its nature as an isometric sticking point.