Augmented Reality Visualization of Wearable Strain Sensor Data for Monitoring Low Back Activation During Weightlifting

Abstract

Resistance training is a widely practiced method for building strength, endurance, and muscle definition across various muscle groups. Certain weightlifting exercises are designed to isolate specific muscles. However, unintentional lower back engagement during these movements can reduce the effectiveness of the exercise and increase the risk of muscle strains that can lead to injury. Addressing incorrect form in weightlifting has been accomplished by a variety of methods, including wearable sensors, but there exists a need for a real-time, noninvasive solution to correct weightlifting form on-thefly. To address these challenges, an augmented reality (AR) interface was developed to directly provide form feedback to the weightlifter based on wearable sensor skin-strain measurements from Motion Tape (MT), which is a self-adhesive skin-strain sensor formed by drop-coating piezoresistive carbon nanomaterial solutions directly onto kinesiology tape. Participants performed sets of 10 repetitions of biceps curls (where low back activation is undesirable), with and without the aid of AR feedback. During testing, each participant wore a pair of MT sensors on their lower back at the left and right sides of the pelvis. These MT low-back strains were displayed in real-time during exercise in the Microsoft HoloLens 2 headset. Analysis of the test data showed that MT recorded lower levels of low-back engagement across three sets of each exercise when the subject was aware of the strains visualized in AR.