High Intensity Therapeutic Laser Induced Changes in Cross-sectional Area of Hamstring Muscle: A Case Report

Ultrasonography can provide a clear depiction of Muscle Thickness (MT) and Cross-sectional Area (CSA) while monitoring muscle contraction. Estimating muscle contraction through ultrasonography with physiotherapy interventions has shown to be a beneficial method for training tightened muscles. A 26-year-old male patient presented to physical therapy with a diagnosis of acute hamstring tightness in both lower extremities, based on clinical examination. Muscle tightness was confirmed through the CSA of the hamstring muscles using ultrasonography. A total of six sessions over two weeks, three times per week, including High-Intensity Laser Therapy (HILT) on each hamstring muscle using the contact method, were applied. Circumference and area of each hamstring muscle were measured through ultrasonography, along with flexibility using the sit-toe and touch test and the Active Knee Extension (AKE) test, both pre-and post-intervention. At the end of the sessions, the subject reported clinically meaningful improvement in outcome scores. This case illustrates the improvement in hamstring muscle flexibility as observed in radiological ultrasonography findings following HILT intervention in a subject with hamstring muscle tightness.