Toning shoes - a bluff?

There are an increasing amount of toning shoes out on the market. MBT may have been the first ones when they introduced the Masai Barefoot Technology in 1996. They claim that natural instability has amazing health benefits. The idea is that the shoe mimics walking on soft uneven ground. Skechers launced their Shape Ups, and Reebook have followed up with their EasyTone.

A team of scientists from the Exercise and Health Program at the University of Wisconsin designed two studies:
1) An evaluation of exercise responses to walking in toning shoes vs a running shoe
2) An evaluation of muscle activation when walking in regular athletic shoes compared to toning shoes

In the first study they monitored oxygen consumption, heart rate, ratings of perceived exertion and caloric expenditure. In the second study the researchers used electromyography (EMG) to record muscle activity in the gastrocnemius, rectus femoris, biceps femoris, gluteus maximus, erector spinae and rectus abdominis muscles. In other words the calf, thighs, buttocks, back and abs.

Although the studies are small, with only 12 participants in each study, it is interesting to see that none of the toning shoes showed statistically significant increases in either exercise response or muscle activation during the treadmill trial.

So is it a bluff? I'd say that In terms of what they promise they sure are a rip-off...

Source: American council on Exercise