Over the past few years more and more shoe companies have been branding and advertising ‘workout’ sneakers that promise to tone your buttocks and thighs by simply wearing the sneakers during normal daily activities. Consumers have responded favorably to such advertising gimmicks and on any given Saturday at the grocery store, a handful of shoppers can be spotted sporting these rocker-bottom ‘kicks.’
So, how good or bad are these revolutionary toning sneakers for you? Well, the jury may still be out on some of the claims by these shoe companies, but we do know that the have caused some problems in the lower extremities! Below are a few of the claims that shoe companies are using to reel in consumers, followed by some of the problems Podiatrist are seeing in response to such purchases.
The Claim: The sneakers, by design, create an unstable center of gravity that stimulates the muscles in your lower extremity to work harder in order for you to maintain balance.
The Science: Creating an unstable center of gravity does induce the muscles of the legs and core to work harder to overcome that imbalance. Try standing on one leg. When you try to stand on one leg, it takes a few seconds for you to find your balance and you can feel yourself teetering back and forth to maintain an upright position. The leg that remains on the ground has all the muscles in it working hard to keep you standing. This claim and the science behind it make perfect sense.
The Problem: Some patients may not have the muscular strength or the appropriate level of balance for their body to accommodate to the unstable center of gravity that the sneakers induce. Therefore, rather than increasing their muscle strength and stability, they are suffering from injuries such as lateral (outside) ankle sprains and falls! Ankle sprains, depending on the severity, can be very debilitating injuries and especially in older patients, recovery is not always optimum.
The Claim: Walking in these sneakers is like walking on sand. The central portion of the sneaker elevates your foot off the ground and therefore, allows your heel to sink below ground level during normal walking. This forces the muscles in your legs to work harder to overcome that resistance in order to propel you forward for proper gait.
The Science: Picture a stability exercise ball that so many people at the gym use for doing sit-ups. By balancing on the ball alone they are working their core muscles and when leaning backwards, their back, shoulder and head fall below the level of the ball. They are in what is called a “negative position,” which increases the resistance and stability needed to complete a forward sit-up. This increases the workout factor on the body’s core muscles and yields greater results. This same technology is inherent to rocker-bottom workout sneakers. By falling into a negative position where the heel sinks below the level of the foot, the muscles in the legs must work harder to overcome that resistance. This claim makes perfect sense.
The Problem: By placing your foot in a negative position as the heel sinks backwards, stress is placed on the muscles in the back of the leg as they lengthen to accommodate the change. For patients that have tight posterior leg muscles (mainly the achilles tendon made up of the gastrocnemius and soleus muscles), the negative position can create problems! Patients are coming into the Podiatrist office complaining of posterior heel pain and are being diagnosed with achilles tendonitis (inflammation of the sheath surrounding the tendon), calcifications of the tendon (reactive boney growth within the tendon secondary to excessive stress) and retrocalcaneal bursitis (inflammation of the bursa or cushiony sack between the achilles tendon and the bone). None of these diagnoses sound like much fun, and I can assure you they are not! Often patients have significant pain and if not treated in the early stages, patients can suffer an achilles tendon rupture; a very difficult injury to overcome.
Next time you see a commercial advertising rocker-bottom workout sneakers, you’ll be a little more informed about the potential lower extremity problems they can create. If you chose to make a purchase, just use caution. If you start to suffer aches and pains in your feet or legs, discontinues wearing the shoes and see your Podiatrist for evaluation.