I am sure you have seen these relatively new fitness shoes with a rocker bottom.   They go by names such as Rock N Fit, Toning Shoes, Shape Ups and Rock & Tone.   Many patients have asked me about these shoes, whether they live up to their claims and are a good investment. Let us examine the claims of these shoes and determine who may find them beneficial:

Claim #1 - More toned and strengthened leg, back, buttock and abdominal muscles. These shoes may in fact activate muscles better than normal shoes but I have not seen the research to support this claim.  Regardless of that, there are better ways to strengthen your lower body and abdominal muscles than these shoes!  If these shoes make you feel more like walking and they get you off the couch, then the result will be improved muscle tone in your legs versus lying around and doing nothing.  Do not buy these shoes to strengthen your muscles - buy them if they motivate you to walk more.

Claim #2 -Reduced body fat. In general, if you are exercising to lose weight, and you are activating more muscles via exercise, these shoes or ANY SHOES will help you reduce body fat through metabolic changes and calories burned.  Big disclaimer here (and on every other weight loss infomercial in small print or said very quickly by the spokesperson) WHEN COMBINED WITH A LOW CALORIE DIET!  Basically, you still will not lose much body fat by walking in these shoes, unless you are combining your efforts with a healthy diet.  So, do not buy these shoes as your sole means to losing weight - unless you plan on changing your eating habits in conjunction with starting an exercise program.

Claim #3 - Improved circulation, aerobic conditioning and exercise tolerance.  It makes sense that increased muscle activation in your legs will improve circulation, because muscles that are working require blood flow.  I believe it is a stretch to claim that this would lead to improved aerobic conditioning and exercise tolerance.  Once again, there are better ways to achieve improved circulation, aerobic conditioning and exercise tolerance through exercise.

Claim #4 - Improved posture, relieved muscle tension and back/joint problems. This assumes that there is improved posture with these shoes, which I have not witnessed clinically.  The continuous motion necessary to "stand still" does not necessarily correlate with improved pelvic stability and therefore less back pain, in many people.  Women with hypermobility (extra motion in their spine) especially into lordosis or arch of the spine, may find that these shoes actually increase back pain by promoting more motion in an already mobile lower back and pelvic region.  Individuals with limited motion in the foot and ankle may benefit from the rocker bottom on the shoes to ease stress to degenerative joints.  Men with stiffness and limited back and pelvic motion, may benefit from the added movement that these shoes provide in standing.

The studies used to support these claims are often commissioned by the shoe manufacturer and therefore questionable in the accuracy of these claims. As a physical therapist I am trained to evaluate the biomechanics of the body, how it moves and functions and how alterations in mobility, strength and balance can affect a gait pattern.  The questions I would ask before purchasing these shoes are:

1.  What do these shoes do biomechanically?

2.  Are these shoes right for me given my individual needs?

The key benefit I see from these shoes is their assistance with roll off, an important phase at the end of the gait cycle. Individuals with stiffness in the big toe or ankle or mild weakness in the muscles about the foot and ankle may benefit from this rocking action, which assists during the lift off phase of the toe and promotes a more fluid gait.   For example, if you have severe arthritis, contributing to loss of mobility in the ankle and/or great toe, you many find these shoes helpful.  If you have mild weakness in the calf, possibly from a nerve or Achilles tendon injury, these shoes will assist you as you push off. I have also seen an improvement in patients with mild foot drop, who use the rocker bottom shoe, as there is less "foot slap" in the deceleration phase after heel strike to toe off.  Patients with moderate to severe weakness in the leg tend to have too much instability to allow for these shoes to be appropriate. 

The other benefit, according to the manufacturers, comes from this "natural instability",, inherent in the shoes due to the rocker bottom.  With your foot in constant motion, they claim there is increased muscle activation and "toning" of the lower body musculature. As a therapist, the claims of increased muscle activation make sense, because your body will constantly seek a balanced state and the required movement to "stand still" does seem like it would increase muscle activity.  As for the claim of increased muscle activation during gait, I would like to see further independent studies to support that claim.

In summary, while these rocker bottom shoes probably do not live up to all the claims of the manufacturer, they may be beneficial for some individuals.

Consider these shoes if you:

• Have limited foot or ankle motion and difficulty with the normal "rolling motion" which follows heel strike to toe off
• Have mild weakness in the calf, like a "foot slap" or mild "foot drop."
• Have stiff legs and a stiff back.
• Will walk for exercise and they make walking more enjoyable for you.

Avoid these shoes if you:

• Have significant weakness in your leg, particularly at the knee, foot or ankle and thus wearing these shoes would create more instability.
• Already have balance issues due to neuropathy, weakness, vertigo, etc.
• Are very mobile in your spine and legs.
• Are weak in general, with a poor gait pattern due to other issues like a hip replacement, a stroke or lengthy illness.
• Believe they will help you lose weight without altering your diet.