Abstract
                ABSTRACT   Background: Many peoples suffer from tight hamstring muscles which predispose them to injury when they engage in vigorous physical  activity. Ultrasound therapy have been used to enhance the effectiveness of muscle stretching, but evidence supporting their benefits is  confusing.   Aims & Objective: The Objective of the current study is to compare the immediate effect of ultrasound (US) and static stretching  exercise on the extensibility of hamstring muscles.  Materials and Methods: Forty normal Participants between the ages of 18 and 21 who demonstrated at least 15 degrees of unilateral  hamstring tightness. They were randomly assigned to 1 of 4 groups: (1) ultrasound therapy; (2) 30 second static stretching; (3)  ultrasound therapy and 30 second static stretching; and (4) control group which don't receive any treatment. The Main Outcome  Measure was Hamstring extensibility measured by active knee extension test (AKE). Differences were compared within groups and  between treatment groups using one way analysis of variance.   Results: There was a significant difference between pre and post-treatment in all treatment groups (p<0.05), but there was no significant  difference regarding the control group (p>0.05). 30 second Static stretching exercise followed by 1 MHZ ultrasound therapy showed a  significant increase in AKE when compared by sole treatment or control group (p<0.05).  Conclusion: The use of ultrasound therapy followed by 30 second static stretching enhance the flexibility of hamstring muscle. This  results can aid in designing physical therapy protocols for similar conditions.