Table 2. The split-split-plot design. The lifting height was the whole-plot factor, the lifting method was the subplot factor, and the lifting speed was the sub-subplot factor in this experiment.

	Lifting height (whole-plot)
	FK			FS
Lifting technique (subplot)	Squat	Stoop		Squat	Stoop
Lifting speed (random order)	VF	VF		VF	VF
	F	F		F	F
	M	M		M	M
	S	S		S	S
	VS	VS		VS	VS