SHOE SOLE THICKNESS AND HARDNESS INFLUENCE BALANCE IN OLDER MEN

Objective: To test the hypothesis that shoes with thick, soft midsoles, such as modern running shoes, provide better stability in older individuals than those with thin-hard midsoles. In addition, we examined the relation between footwear comfort and stability and stability when barefoot. Design: Randomized-order, cross-over, controlled comparison. Setting: Subjects were drawn from an internal medicine practice. Participants: A random sample of 25 healthy men, minimum age 60 years. Additional selection criteria were absence of disabilities influencing ability to walk and lack of history of frequent falls. Measurements: Balance failure frequency, which was defined as falls from the beam per 100 meters of beam walking when 10 passes were made down a 9 M long balance beam. Comfort rating was based on an ordinal scale. Results: Contrary to the hypothesis: (1) midsole softness was associated with poor stability (F(2,48) = 17.9, P < 0.0001); (2) thick midsoles also provided poor stability (F(1,24) = 7.36, P < 0.01). When barefoot, subjects showed 19% higher balance failure frequency than with the poorest shoe and 171% greater than the best shoe (t = 5.33, P < 0.0001). Higher comfort was generally found in shoe types associated with higher balance failure frequency. Conclusions: For optimal stability, shoes with thin, hard soles are preferable for older individuals. Health professionals should exercise caution when recommending shoes with thick, yielding midsoles, such as running shoes, to unstable elderly individuals. Older men and women with a history of falls or who are obviously unstable, should avoid barefoot locomotion.