This is a common test used by therapists, athletic trainers and others to assess hip extension mobility. It can be performed with the help of another person or as a self-assessment (a mirror is handy in this case).
In the pull, hip extension range of motion is greatest at the end of the second pull/finish (165-185 degrees); in the jerk, hip extension is used to finish the drive phase and to “split” the pelvis/hips during the receiving position of the split jerk (Figure 3.14). This means putting one hip into extension while the other one is flexed. Obviously a certain amount of hip mobility is required for this, as well as a significant amount of stability through the trunk and pelvis in order for most of the motion to come from the hip joints as opposed to the low back or pelvis. Add to this the fact that the arms are overhead supporting load, and we have a pretty complex movement pattern to deal with. Don’t worry—we keep it simple with this test. Stability and integration overhead will be coached later. Let’s just look at the mobility capacity of the joints first—movement potential.
Figure 3.14 We use hip extension to generate power in the finish of the pull and in the jerk drive, and for the split position of the back leg in the jerk.
Starting Position
Sit on the edge of a table or bench with the crease of the back of your hip near the edge.
Make sure the surface is high enough so that the ground doesn’t limit the range of motion.
Grab both knees and lie on your back, flexing your hips past 90 degrees.
Execution
Put your hands around one knee only, keeping that hip flexed past 90 degrees.
Let your other leg slowly drop toward the ground in the pure sagittal plane.
Keep the knee of the down leg flexed to 90 degrees.
Keep the lower back and pelvis motionless as the leg lowers. This is important to isolate true hip extension. (Figure 3.15)
Figure 3.15 The Thomas Test start position, the test performed as a self-assessment, and testing using a partner.
Key Points
We are looking for the drop leg to reach the table or bench (parallel with the ground) with the knee bent to about 90 degrees.
Does the athlete achieve this?
If yes, the athlete likely possesses adequate hip extension mobility to achieve full hip lockout during the finish and split. Having the knee bent increases the sensitivity of the test by increasing the stretch on the quad muscles, which means we can rule out truly short hip flexors as being the primary limiting factor to achieving active hip extension.
If no, allow the knee of the down leg to relax/straighten a bit (Figure 3.16). That will slack the quad musculature and for some allow for increased range. For an athlete who experiences this increase in mobility with a straight knee, it may indicate that he or she should spend a little more time during warm-ups making sure that that back hip of the jerk is locked out to the best of his or her capacity.
Figure 3.16 By altering knee flexion/extension, one can get a sense of hip extension in a position that mimics the pull or jerk. For some, a straight knee will allow for slightly more hip extension mobility.
Now perform both bent and straight knee tests by allowing the leg to fall out to the side into slight abduction (Figure 3.17). Note any differences in range of motion when you allow this to happen. If hip extension was limited in the straight sagittal plane, but the hip falls freely into full extension if you allow a bit of abduction, this again may be an indication that experimenting with a slightly wider pull stance or jerk stance may afford you a bit of hip extension range. Letting the leg fall out to the side during this test has often been seen as an unwanted compensation.
However, we will view it as simply respecting anatomy. Remember our goals for screening—don’t chase ghosts, and use the tests to learn a bit about your body.
Figure 3.17 A way for a lifter to determine the position that allows for maximal hip extension is by experimenting with various degrees of abduction in the Thomas Test.
This test does not have predictive power. For example, if an athlete demonstrates full range of motion during the test, that does not guarantee that they will utilize full hip lockout at the top of the pull or drive of the jerk, but it does demonstrate his or her capacity to do so.
If the lifter has an apparent hip extension limitation and also has tendencies to cut the finish of the pull short of full extension, or relies on spinal
hyperextension in the jerk, which affects trunk stability, then we will work to improve the lifter’s ability to express hip extension within ranges that they can control.
Figure 3.18 In the first picture is an example of full hip extension capacity
In this scenario, since our goal with movement screening is simply to determine if the joints can get into the positions that we want to load, the active straight leg raise can be modified to a passive straight leg raise, in which the lifter uses a band to bring the leg into the straight leg raise, or a partner helps. If the leg reaches the standard of 70-90 degrees, then we can surmise that the joint can get into the position, and the active straight leg raise is limited by pelvic position and/or motor control.