The chic Vionic Nala Thong Sandal features bold geometric studs, sure to be the focal point of any warm-weather look. Features For the greatest comfort, we recommend wearing your new Vionic footwear for just a few hours for the first few days to allow your feet to adjust to the new level of orthotic comfort and support. Within one to two weeks you should find the product complete Scientifically Proven to Alleviate Heel Pain* *Based on a peer-reviewed clinical study partially funded by Vionic on people experiencing moderate, non-traumatic heel pain. Vionic contoured sandals were shown to be comparable in effectiveness to Vionic orthotic inserts. Support Technology:.