This is a question that you may have asked yourself if you have been treated at Foundry for knee pain. Whether you suffered an acute injury to your knee or have a pain that has slowly worsened over many months, the true cause of the injury may not be located at the knee at all. Rather, it is more likely that a biomechanical deficiency at a different joint of the lower extremity, such as the hip or ankle, that may be causing the knee to suffer.
When our foot strikes the ground (while jumping, running, etc.), several muscles must co-activate with correct timing and strength to create and maintain the stability to allow your body to shift weight on to the lower extremity and create enough force to push off of the ground again to continue our movement. In order to achieve this without dysfunction, we must be able to control what is called the “Dynamic Q-Angle.” The Q-angle is the alignment of three anatomical landmarks; the ASIS (front of the hip), patella (knee cap), and tribal tubercle (top of the shin). The Q-angle becomes dynamic when it is measured with movement (landing on the foot when walking, running, and/or jumping.) When the femur adducts (knee falls inward) excessively and the angle becomes too sharp, injury can occur. This injury can range from mild diffuse pain across the front of the knee that is seen in patellofemoral pain syndrome, to a structural injury such as a torn ACL.
There are a variety of reasons as to why our dynamic Q-angle may be increased. The one that we will focus on today is hip strength. You may notice during an initial evaluation or re-evaluation that your physical therapist has had you lie on your side and lift your leg straight up in the air against resistance. This manual muscle test is used to assess hip abduction strength (moving the leg outwards to the side), or more specifically, the strength of the gluteus medius. The gluteus medius, or “glute med” for short, is a muscle located on the outer hip that helps to control the alignment of the entire lower extremity when the foot is in contact with the ground. It is a muscle that is very important during running, walking, and jumping, but is unfortunately rarely exercised, as we tend to exercise the muscles in the front and back of our bodies much more than the muscles on the side of our bodies. Without the requisite strength and muscle activation patterns of the glute med, the knee will fall inwards during activity, resulting in injury.
If you are a patient that exhibits this lack of strength, you may notice that many of the exercises that you perform in physical therapy will be focused on increasing hip strength to maintain proper alignment at the knee. These exercises may include a mix of progressions that begin on the table and can include positioning of double limb stance (standing on both legs at the same time) and single leg stance. Single leg stance exercises will be of great importance to patients who are looking to return to running/sports, as running consists of rapid weight shifts from one leg to the other, during which one leg must support the entire weight of the body. Also, it is imperative that any athlete competing in sports is able to control their Q-angle when landing from a jump to prevent injury/dysfunction.
It is important to remember that the goal of all physical therapy treatments is to treat the cause of the injury/dysfunction rather than merely treating the symptoms. Your therapist will always focus on seeing the “big picture” and work to improve the entire kinetic chain to help you to achieve your best results possible.