Strength Influences on Joint Loading and Lift Strategy: A Comparison of Back-Sparing and Freestyle Lifts

This project aimed to 1) compare peak joint loading of the knee and low-back between freestyle and back-sparing (squat and half-kneel) lift techniques across levels of isometric knee extension strength and back extension strength, and 2) investigate whether the difference between knee extension and back extension strength was predictive of their lift strategy (i.e., leg- or back-preferred) during a symmetrically-constrained freestyle lift. 

Participants (18-50 years old) were invited to the lab, where they performed four different lift techniques: freestyle, symmetrically-constrained freestyle, squat, and half-kneel. Whole-body motion and joint loading were recorded through Optotrak motion capture and floor-embedded force plates. Participants then returned for a second visit to assess their maximal isometric knee extensor and back extension strength using a Biodex Isokinetic Dynamometer.  

This data provides fundamental knowledge on how joint strength and lift technique independently and interactively influence peak joint loading during lifting, helping to inform safe lifting guidelines and develop strength training interventions for preventing injuries in the workplace. 

For more information on this project, please contact Sarah Hallman.