Torsion during hip external rotation (ER) and extension maybe responsible for certain

Chapter 9, Problem 45

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Torsion during hip external rotation (ER) and extension maybe responsible for certain kinds of injuries in golfers andother athletes. The article Hip Rotational Velocities Duringthe Full Golf Swing (J. of Sports Science and Medicine,2009: 296299) reported on a study in which peakER velocity and peak IR (internal rotation) velocity (both indeg.sec1) were determined for a sample of 15 femalecollegiate golfers during their swings.a. Is it plausible that the differences came from a normallydistributed population?b. The article reported thatfor ER velocity and for IR velocity.Based just on this information, could a test of hypothesesabout the difference between true average IR velocityand true average ER velocity be carried out? Explain.c. The article stated that The lead hip peak IR velocity wassignificantly greater than the trail hip ER velocity. (The phrasing suggeststhat an upper-tailed test was used.) Is that in fact thecase? [Note: in Table 2 of the article is erroneous.]