• Physical Therapy Korea
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• v.21 no.1
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• pp.47-54
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• 2014

The aim of this study was to compare the duration of hamstring flexibility improvement after 3 stretching interventions in people with limited hamstring flexibility. Twenty-two subjects (12 men, 10 women) with limited hamstring flexibility of the dominant leg received 3 stretching interventions- modified dynamic stretching (MDS), hold-relax (HR), and static stretching (SS)-in a random order. All the subjects received all 3 interventions at intervals of at least 24 hours to minimize any carry-over effect. Modified dynamic stretching was applied as a closed kinetic chain exercise in the supine position by using the sling suspension system (Redcord Trainer(R)). The SS and HR interventions were individually performed in the straight leg raising (SLR) position, and all 3 interventions were performed for 3 minutes. Outcome measures included passive knee extension (PKE) measurements. Five post-test measurements were recorded for all subjects at 3, 6, 9, 15, and 30 minutes after the interventions. MDS was associated with a significant increase in knee extension range of motion even at 30 minutes post-treatment. In contrast, the HR and SS stretching methods showed increased hamstring flexibility for only 6 minutes post-treatment. Improvements in the range of motion of knee extension (indicating enhancement in hamstring flexibility) with MDS were maintained longer than those with the HR and SS interventions. Therefore, MDS may be more effective than the other interventions for maintaining hamstring flexibility.

• Journal of The Korean Society of Integrative Medicine
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• v.1 no.4
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• pp.25-35
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• 2013

Purpose : The purpose of this study was to compare the muscle activities of infraspinatus, serratus anterior, upper trapezius, and triceps brachii in different supporting surface intervals during push-up exercise. Method : Subjects of the study were 18 healthy male students without any orthopedic or neurological injuries including neck and shoulder surgeries and can perform a push-up exercise required for the study. EMG was used to measure the muscle activities of four muscles. Result : There were statistically significant differences of all the muscles in three different supporting surface intervals(p<0.5). Muscle activity of upper trapezius was the highest(MVIC 39.40%) in the narrowest width and the lowest in the widest width. In infraspinatus, muscle activity was the highest(MVIC 36.23%) in the narrowest width and the lowest in the widest width. In serratus, muscle activity is the highest(MVIC 58.04%) in the widest width and the lowest in the narrowest width. In triceps brachii, muscle activity is the highest(MVIC 68.51%) in the widest width and the lowest in the narrowest width. Conclusion : Muscle activities are at the highest with the narrowest width in the upper trapezius and the infraspinatus. In the serratus and triceps brachii, however, muscle activities are at the highest with widest width.