Roger Ribas Manero, a researcher in King’s College London is developing a pair of leggings that measures muscle fatigue during physical activity.
“Several electric-thread-based sEMG sensors have been embedded on the fabric according to the SENIAM project in order to capture muscle activation signals,” the official site of the Department of Informatics at King’s College London says. “These signals are later on processed by an Arduino micro-controller in order to obtain muscle fatigue values. The goal of this project is to elucidate how different running surfaces lead to different muscular groups fatigue and hence establish a classification on these surfaces. This will help to prevent Running Related Injuries (RRIs) and improve runners’ performance.”
There are a number of advantages to having electrodes and circuitry embroidered into an ordinary pair of leggings, Technology Review reports. The embroidered circuit pattern allows the electrodes to automatically position themselves in the correct anatomical locations, so the user will need no prior medical experience in order to properly wear the pants. Also, since the circuitry is double-stitched in a zigzag pattern, it allows for stretching.
Muscle fatigue is defined as the point at which muscles can no longer contract. This indicates that the body is no longer receiving energy from foods eaten, stored glycogen or body fat. Symptoms of muscle fatigue include leg twitching, reduced activity levels, weak grips and general lack of energy.
Until now, muscle fatigue has been rather difficult to measure. The most sensitive method relies on a fine wire inserted into the muscle to measure the electrical stimulation of nerves in order to determine the amount of force the muscle can exert. A different, more flexible approach uses electrodes on the surface of the skin to monitor the electrical activity of the nerves below, but this requires the electrodes to be precisely placed. With Manero’s research, this may no longer be an issue.
In order to test the product, Manero’s team of researchers asked two runners to wear the leggings while jogging around 5-kilometer routes across three different surfaces — an asphalt track, an athletics track and a sand track. The leggings recorded the muscle activity throughout, indicating that the runner’s leg muscles begin to work harder and tire quickly after a minute or two. This tiring occurs the quickest on sand and the slowest on an athletics track.
Manero’s leggings provide further proof that running on harder surfaces slows muscle fatigue in general. According to New York Times, the body automatically adjusts to different surfaces to keep forces constant when foot strikes plate. This process is mimicked by cushioning in shoes.
“If you run on a hard surface, your body decreases its stiffness,” Stuart J. Warden, director of Indiana University’s Center for Translational Musculoskeletal Research, said in an interview with the New York Times. “Your knees and hips flex more. On a soft surface, your legs stiffen.”
Wearable technologies are on the rise, with devices like Fitbits calculating the number of steps people take in a day and devices like the Apple Watch coming with heart rate monitors. Manero’s product is slightly different, but will still revolutionize the way we look at wearable technologies in regards to fitness. In a new era of wearable technologies, we will be able to monitor the number of steps a person takes as well as the muscles and energy exerted in the process.