Several months ago, Paul Bruno DC PhD, provided us with a review of his research activity on Research Review Service. To provide you with a quick and dirty rundown, he essentially described the evolution of Janda's Prone Hip Extension test and looked at its reliability and validity in determining muscle activation orders. In short, through his research, he found that subjects with and without low back pain demonstrated variable results with respect to the activation orders of the glutes, hamstrings, ipsilateral and contralateral erector spinae and therefore concluded that the clinical importance of this test's findings were still unclear at best.
For those of you unfamiliar with this test, essentially the objective is to look at the relative onset of firing between the glutes, hamstrings, ipsilateral and contralateral lumbar erector spinae such that in an ideal world, the relative activation of the gluteus maximus and the hamstrings fire first in relation to the erector spinae.
In light of the controversy surrounding this test, Greg Lehman, a dual chiropractor and physical therapist, provided us with an excellent post detailing the current state of the literature on this test as well as some of his thoughts on its clinical utility. In short, while he concludes in his post that for most, a delay in glute max firing seems to be the norm, activation and amplitude of firing can be modified and that abnormal activation patterns (according to this test) has yet to be proven...scientifically...to be dysfunctional.
As such, Andreo Spina also provided his thoughts on the utility of this test and described his preference for glute max testing via modification through testing at approximately 30 degrees of hip flexion. He also discussed the utility of supine bridge testing, ala Stuart McGill, in consideration of the fact that during walking, the glute max tends to "dim down" in activity during hip extension beyond 30 degrees (of flexion).
Many clinicians who utilize the prone hip extension test however, still argue that clinically relevant information can be revealed irrespective of the current state of the literature. This is not surprising since research commonly isolates single rather than multiple variables for scientific scrutiny. Therefore, while it may be too early to throw this particular test out with the bath water, it is important that we be cognisant of the evidence and understand that hip extension motor patterns should be cross-examined via a variety of testing means such as in supine, modified prone, side-lying and upright (half-kneel and single leg stance) positions.
That is...by just watching an athlete move.
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