Research recently examined back squatting using two different chain techniques. Researchers tested one experienced male weight lifter for this case study. Researchers compared linear and double looped supplemental heavy resistance chains to the back squat movement. The linear chain technique hangs the chain directly from the bar, the double looped technique uses a smaller chain to adjust the height of the looped chain.
The data collected found that the double looped supplemental heavy chain set up resulted in an astounding 78-89% unloading of the chain weight at the bottom of the squat. The linear hanging supplemental heavy chain set up resulted in only 36-42% unloading. Researchers concluded that the double looped technique provided nearly two times the resistance at the top of the squat. Further research is need due to the case study nature of this research.