The right hip abductor musculature has beem reported to demonstrate "stretch weakness" attributable to chronic elongation imposed by standing posture common to right-handed healthy persons
Kendall and associates have described the concept of "stretch weakness".
The purpose of this study was to assess isometric hip abduction torque and surface electro-myographic activity(using MYOMED 432)in a sample of 40 healthy right-handed person(20 male,20 female), all of whom agreed to the participate in the study, and compare side difference in the hip abductor musculature. In order to assure the statistical significance of the results, the paired t-test was applied at the .05 level of significance.
The results were as follows :
1. The difference in apparent leg length of right and left legs was significant at the .05 level.
2. There was a significant difference between right and left pelvic height(standing position)at the .005 level measurments, and scapula beight at the .05 level.
3. Power measuements and action potenials of right hip abductor were greater than the left hip abductor regardless of the range of joint motion(inner range, outer range).
4. The difference in muscle power and action potentials according to inner of outer range of both hip abductor were significant at the .05 level.
5. In supine during active left hip abduction, the appearance of action potentials in the right hip abductors is indicative of contra-lateral effect(p<.005).
These results suggest:In healthy right-handed persons, the apparent leg length on the right is longer than on the left, and pelvic height is elevated on the right side.
Muscle thorque and muscle action potentials of the right hip abductor are higher than those of the left hip abductor in the lengthened position.
Therfore, the results in this study are contrary to Kendall´s. This type of study should be carried out in many physical therapy departments.
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