Torsion during hip external rotation and extension mayexplain why acetabular labral

Chapter 12, Problem 65

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Torsion during hip external rotation and extension mayexplain why acetabular labral tears occur in professional athletes.The article Hip Rotational Velocities During the FullGolf Swing (J. of Sports Science and Med., 2009: 296299) reported on an investigation in which lead hip internal peakrotational velocity (x) and trailing hip peak external rotationalvelocity (y) were determined for a sample of 15golfers. Data provided by the articles authors was used tocalculate the following summary quantities:Separate normal probability plots showed very substantiallinear patterns.a. Calculate a point estimate for the population correlationcoefficient.b. Carry out a test at significance level .01 to decidewhether there is a linear relationship between the twovelocities in the sampled population; your conclusionshould be based on a P-value.c. Would the conclusion of (b) have changed if you hadtested appropriate hypotheses to decide whether there isa positive linear association in the population? What if asignificance level of .05 rather than .01 had been used?