This prospective pilot study is designed to evaluate the clinical effectiveness of a wound care ultrasound treatment protocol for sub-acute or chronic wounds of the lower extremity and of any etiology. The Viana-Pompeo (VIP) ultrasound protocol consists of high intensity, low frequency, contact ultrasound therapy (with Sonoca-180) followed by low intensity, low-frequency, noncontact ultrasound therapy (with MIST Therapy). Previously published healing rates for each of the ultrasonic therapy modalities will be used as a comparison.