Monday, January 12, 2015
Does Movement Impact Hip Pain - Part II
Last week we looked at positions that we know put the hip at risk for femoral acetabular impingement (FAI). We concluded the last blog by asking the question, should we look at the previously mentioned movements (adduction, internal rotation and flexion) that occur in the lower kinetic chain during weightbearing motions so we may identify those at increased risk for FAI?
To answer that, we first have to see is what do these movements look like during full weightbearing? How might that movement be represented, for example, in a full squat? Since this is such a common exercise in sports and has such a high correlation to athletic performance, it would make sense to look at the squatting position. In this example (pictured here), we can see an athlete that is demonstrating a lateral shift to the right. This lateral shift, will result in greater hip flexion and a greater degree of adduction at the right hip versus the left. This brings the greater trochanter and intertrochanteric line of the femur in closer proximation to the acetabular labrum. Both of these movements combined, under full weightbearing positions could result in FAI of the right hip. If this lateral shift is present under full body weight conditions, we can predict that these motions will be similar or even slightly worse under higher loading conditions (squatting with weight). That being said, if this motion is never identified and/or corrected, then there is a high probability that it will remain no matter what surgical technique or intervention is performed to aid in treatment of the FAI. But, one movement alone will not give us enough information about what our intervention should be. So are their additional movements we can look at?
In the 2011 American Journal of Sports Medicine, Grindem et al showed that single limb testings was a better predictor of function than bilateral testing. Myers et al, in 2012, showed that asymmetry in single limb performance was a better indicator of risk and Kristianslund et al, in 2013, showed that single limb performance was a better indicator of risk in sport. So considering these as well as numerous other studies, it would make sense to assess single limb performance for potential risk for development of FAI. In this example (pictured here), we can see an athlete demonstrating adduction, internal rotation during a single leg squatting activity (flexion of the hip). The combination of these motions again brings the greater trochanter and intertrochanteric line of the femur in closer proximation to the acetabular labrum. Under single limb weight bearing positions, the pressures at the joint are much greater than bilateral testing and could give a better indication of risk for FAI.
Just using these two movements alone (squat and single leg squat), we can see some potential opportunities for strengthening of the system that could lead to a reduction of the lateral shift and adduction and internal rotation that is observed. So how do we address these?
There are multiple ways to address this which is beyond the current scope of this paper and which has been discussed in detail in our previous blogs. Whatever we do from a training perspective, we should have one thing in mind, train to reduce the movements associated with risk that my athlete may present with during athletic participation. That said, we do want to mention what you should NOT do from a training perspective. During our training programs, our goal should be to perform closed kinetic chain functional activities (like squats) which develop motor learning patterns similar to what we want to see during activity or sport. What we know, is that in athletics, there are certain movements that put athletes at risk. Our goal should be to train movement patterns which PREVENT these movements.
Pictured here is a common exercise used to improve movement during the squatting motion. In athletics, we know one of the main risk factors for ACL injuries as well as FAI is adduction, especially if this occurs during the squatting motion or during single limb activity. This exercise, as performed here, is teaching the athlete to adduct their knees during the squatting motion. By placing the ball between the knees, the athlete must squeeze the ball to prevent it from falling. What is trained is a motor plan that says, when I squat, I want to adduct my knees. This is the exact opposite of what we should be training. This same exercise, performed with a band around the knees (pulling the knees into an adducted position) would cause the athlete to abduct their knees during the squatting motion. Training in this way will create a motor plan that says, when I squat, I want to abduct my knees. By creating this motor plan and strength, the athlete will then decrease the adduction that occurs during the squatting motion and therefore decrease the stress to the acetabular labrum and the ACL.
So, what ever we do from an assessment perspective or a training perspective, thinking about the movements can guide not only how we assess but also how we train? To assess properly will tell us if our interventions are making an impact and will also guide our training interventions. To do this well, will result in improved movement in our athlete during athletic participation and overall improved athletic performance. We hope that you found this blog insightful and useful. As we stated previously, stay tuned and if you like what you see, SHARE THE PASSION! It is the biggest compliment you can give. Follow us on Twitter @ACL_prevention and tweet about it. #DMAOnTheMove and help us spread the passion and #movementonmovement.
Build Athletes to Perform…Build Athletes to Last!™