The Effect of Pelvic Position on Popliteal Angle Achieved During 90:90 Hamstring-Length Test

<jats:sec sec-type="context"><jats:title>Context:</jats:title><jats:p>Hamstring muscle length is commonly measured because of its perceived relationship to injury of both the hamstrings themselves and the pelvis and lumbar spine. The popliteal (knee-extension) angle measured from the starting position hip and knee at 90° is a commonly used indirect measure of hamstring muscle length. When this measure has been undertaken in the literature previously, little attention was paid to the position of the pelvis, which may significantly influence measurements taken.</jats:p></jats:sec><jats:sec sec-type="design"><jats:title>Design:</jats:title><jats:p>Repeated-measures.</jats:p></jats:sec><jats:sec sec-type="setting"><jats:title>Setting:</jats:title><jats:p>University human performance laboratory.</jats:p></jats:sec><jats:sec sec-type="participants"><jats:title>Participants:</jats:title><jats:p>60 healthy physically active males (mean age 20.1 ± 1.8 y, range 18–24 y).</jats:p></jats:sec><jats:sec sec-type="intervention"><jats:title>Intervention:</jats:title><jats:p>The 2 extremes of pelvic position (anterior and posterior).</jats:p></jats:sec><jats:sec sec-type="main outcome measure"><jats:title>Main Outcome Measure:</jats:title><jats:p>Popliteal angle (with maximal knee extension) was measured in 2 positions, 1 of full anterior and 1 of full posterior pelvic tilt.</jats:p></jats:sec><jats:sec sec-type="results"><jats:title>Results:</jats:title><jats:p>The mean difference in popliteal angle between anterior to posterior pelvic positions was 13.4° ± 9° (range 0–26°); this was statistically significant (<jats:italic>P</jats:italic> = .0001).</jats:p></jats:sec><jats:sec sec-type="conclusion"><jats:title>Conclusion:</jats:title><jats:p>The findings of the study indicate that pelvic position has a significant effect on popliteal angle and therefore should be taken into account when measuring hamstring muscle length.</jats:p></jats:sec>