In throwing, running and hitting you need to be able to actively reach a neutral hip position in your trail leg in order to achieve full rotation and transfer forces into the ball. True Hip Extension to neutral (or potentially beyond) is actively being able to move the hip in line with the trunk without compensations from other regions of the body. Continued compensations can lead to pain that will manifest itself in other areas, in this case, it is often noticed in the front of the hip or the lower back. I TRIED TO ACCURATELY ILLUSTRATE WHAT NEUTRAL HIP EXTENSION MEANS IN THE FOLLOWING PHOTOS OF PEDRO AND HARPER. You can see each of them are able to maintain a neutral hip position in order to produce maximal force without resulting in pain or injury. Later in this post I included a picture of excessive lumbar extension from a pitcher to give you an idea of what a true compensation would look like.
When players can’t actively achieve the hip, extension needed to throw and hit they begin to use compensatory patterns because the body will always find the most efficient way from point A to point B. Typically when guys are using these types of patterns they will often complain of back pain or hip pain after or during, pitching, after a session taking a lot of swings in the cage or having a bunch of at bats in a short period of time. The two most common compensations to make up for the lack of active hip extension are to gain that range of motion through lumbar spine extension or through an anterior glide (movement towards the front) of the femur (hip bone) in the socket. To better understand some compensations, we will dive into more detail here.
Lumbar Extension and Low Back pain
As stated before the body is going to find the most efficient way from point A to point B. Given that the body needs to reach some sort of hip extension to have full pelvic rotation and transmit maximal force into the ball, it is going to find a way to reach that point of extension or use “fake extension”. This “Fake Extension” will come from your lumbar spine trying to make up for the lack of hip mobility and your brain will still process this as achieving the proper positon. I’m using the picture below to show, what an extensive lumbar extension compensation pattern would look like. Granted I think this pattern is caused by decreased maximal external rotation of the arm, it is still a great picture to use as an example (you can see how complicated baseball injuries can be, arm restrictions can cause back pain? What? For a later time...)
As you could assume, this pattern, repeated hundreds of times of the course of a start or long batting practice session could result in pain or damage to the structures in those areas.
Anterior Glide of the Femur and Front of Hip Pain
Another slightly more complicated, area of compensation is improper hip joint movement. During a true hip extension movement, the head of the femur will SPIN towards the front of the joint to maintain joint congruency. When moving into extension with combined movements such as moving down the mound (external rotation and abduction of the hip) there will be some, minimal glide in the joint as well. When there is insufficient active, or passive in this case, hip extension you may experience extreme gliding in the joint which will cause stress on the front of the hip joint capsule.
What all that basically means is because of a limitation or restriction elsewhere, your hip bone is jamming into the front of your hip (joint capsule, ligaments, muscles) and causing unnecessary stresses resulting in pain. This is often misdiagnosed as hip impingement which is a completely different case and method of treatment.
How can we tell?
I use a few tests to examine hip passive and active hip extension. First, I will examine an athlete hitting, running, throwing or pitching video. To see if they are getting full hip extension in movements. If not, I will begin to not if the restriction is active or passive. To assess passive restrictions, I will use a Thomas Test, which is essentially having a patient lie on their back and bring one knee to their chest. During this test, you look at the leg that remains extended. You want to examine hip position. Is the hip stuck in flexion? This could have you being to think about limited structures like the iliopsoas muscle or joint capsule. Has the leg deviated laterally? This may have you thinking about soft tissue structures in the TFL. Is the knee extended past 90 degrees? Maybe there is a restriction in the rectus femoris or quad muscles. Maybe the leg is slightly elevated off the table but you don’t notice any restrictions. Well, maybe this person just has a big butt. Next, I move to my first active test. Prone, over the table, hip extension. We use this test if the athlete has full passive motion and want to observe if they can actively move into hip extension. This can help us determine if there is a neuromuscular control issue. Lastly, my favorite test for this is the single knee to chest supine bridge. I love this test because it simulates active hip extension with the typical pelvic and hip alignment of a throwing motion.
Depending on the issue we discover treatment can be anything from soft tissues techniques, such as manual therapy, joint mobilizations, dry needling or active stretching. Neural control interventions like hip controlled articular rotations and joint mechanic interventions or active strengthening like single leg bridges. The interventions chosen are dictated by the restrictions or limitations discovered.