Table 6.

Studies Examining Effectiveness of Floor Surfaces, Mats, Shoes, and Inserts

Author (Year)	Study Population	Brief Summary
Jørgensen et al., (1993)	8 F Danish volunteers performing letter sorting task.	The effect of different shoes and floor surfaces was negligible after 2 h of prolonged standing. Longer durations were not tested.
Redfern & Chaffin (1995)	14 US workers (8 M, 6 F).	Ratings of perceived hardness of flooring affected perception of discomfort and were correlated with measured stiffness. Slip resistant mats and extremely soft mats did not offer marked improvement over mats with more hardness. Use of shoe inserts was perceived as similar to the better-rated cushioning mats.
Krumwiede et al., (1998)	12 US college students.	Mats with the highest compressibility were rated as the most comfortable, but specific mat characteristics that influenced comfort were not apparent.
Madeleine et al., (1998)	13 M Danish volunteers.	Standing on the soft surface produced lower reports of unpleasantness whereas the hard surface showed increased trunk swelling, increased EMG activity in the muscle groups, increased sway displacement, and increased muscle fatigue. Induced muscle pain was lower on the soft surface than hard surface.
Redfern & Cham (2000)	11 studies from 1972–2000 that investigated prolonged standing and floor types.	In a review of 11 studies, authors concluded that softer floors generally resulted in reduced discomfort and fatigue compared to a hard floor, primarily in the lower extremities. Key flooring characteristics influencing discomfort include elasticity, stiffness, and thickness.
Cham & Redfern (2001)	10 US volunteers (5 M, 5 F).	Prolonged standing and floor type had sig. effects on both the subjective and objective fatigue and discomfort, but only during the 3rd and 4th hour of prolonged standing.
King (2002)	22 US assembly line workers (5 M, 17 F).	A mat alone, in-soles alone, and in-soles with mat were rated as significantly more comfortable and less fatiguing than a hard floor condition. No significant differences, however, were noted when comparing the effects of standing on a mat versus wearing in-soles or the combination of standing on a mat with insoles.
Zander et al., (2004)	16 US assembly line workers (2 M, 14 F).	Lower leg volume increased sig. from pretest to posttest while standing for 8h, but there were no sig. differences between any flooring conditions (wood block, anti-fatigue mat, shoe insole).
Orlando & King (2004)	16 US assembly line workers (2 M, 14 F).	Use of mats and insoles reduced ratings of general fatigue, leg fatigue, and discomfort but here were no sig. differences between the flooring conditions (wood block, mat, insoles) compared.
Sahar et al., (2007)	6 randomized control trial studies from US, Denmark, Israel, + South Africa	Based on a review of studies examining effectiveness of insoles, authors concluded that there was no strong evidence that using insoles was effective in the prevention or treatment of back pain.
Bahk et al., (2012)	2165 (1203 F, 962 M) South Korean Workers.	Non-heeled shoes reduced prevalence of varicose veins in women (OR 0.69, 95% CI 0.49–0.97) and men (OR 0.58, 95% CI 0.35–0.96), but not on nocturnal leg cramps with prolonged standing > 4h/d.
Lin et al., (2012)	Expt. 1–13 Taiwan volunteers (10 M, 3 F). Expt. 2–14 Taiwan Workers (6 M, 8 F)	Expt. 1-Foot discomfort (p<0.01) and shank circumference (p<0.01) sig. lower on soft floor (mat). Shoe condition only sig. for discomfort (p<0.01). Sig. effects > 1h standing. Expt. 2-Thigh circumference (p<0.014) and shank circumference (p<0.032) greater on hard floor. Negative effects after 1h standing.