Thong-style flip flops are one of the very hottest styles of footwear these days and they are worn by men and women alike.  Everyone from toddlers to their great-grandparents wear them with little worry that they may be causing pain from the foot to the hip and even into the lower back.

The pain probably comes from an alteration to a person’s normal walking gait, according to Justin Shroyer, a doctoral student at Auburn University’s College of Education Department of Kinesiology, who is studying biomechanics.  He and his team of researchers presented their findings recently in Indianapolis at the annual meeting of the American College of Sports Medicine.

Shroyer measured and videotaped the walking gaits of 39 men and women of college age for his study.  Each study participant wore flip flops over a specially designed platform that measures the vertical force of a walker’s feet as they hit the ground.  After wearing the flip flops, study participants repeated the process wearing athletic shoes.

It seems that study participants took shorter strides when wearing flip flops and their heels produced less vertical force when hitting the ground.  During the swing phase of a stride, participants didn’t raise their toes as high off the ground as they did when wearing athletic shoes, either, probably because of the toe-gripping action needed to keep the flip flops on.

Shroyer’s conclusion is that flip flops aren’t meant to be worn as primary footwear and are best relegated to walking along sandy beaches or to provide temporary relief to tired feet after a long day or grueling exercise.  The absence of foot and ankle support makes flip flops a poor choice for all-day wear, according to Shroyer, although many college students consider them a mainstay of their wardrobes.

Shroyer himself owns a couple of pairs of flip flops but says they are much like traditional athletic shoes in that they, too, should be replaced after several months of wear.  For the purpose of the study, various models of flip flops, ranging from $5 to $50, were used as were various styles and prices of athletic shoes.

Shroyer plans to use the data from this study in his doctoral dissertation, which is based on specialty athletic shoes and their application in biomechanic performance.