The Link Between Hip Dysfunction & Knee Pain
- Pain & Injury • Sept 1, 2020
By Dr. Richard Thompson, DC
3 Minute Read
ne of the most unexpected discussions I have with patients seeking treatment for exercise-induced knee pain is when we identify the cause of their pain to actually be at the hip, not the knee. With these cases, I often do not provide any treatment to the knee. All of our treatment protocols are strictly focused at the hip. Patients are often surprised by this revelation and that this course of treatment actually works, but once the physiological and biomechanical connection is explained, it becomes clear as to why and how this injury occurs.
Let’s first start with a bit of a clinical understanding of this type of injury. The patient experiences gradual onset pain at the knee that begins with prolonged weight-bearing exercise, such as running. The longer they exercise, the more intense the pain gets, to the point where they have to halt the exercise. The pain can be located medially (inside), laterally (outside), or throughout the entire knee joint. Swelling is uncommon, but can be present upon exercise completion. Clicking in the knee is often experienced, but is typically painless. Non-weight bearing exercise, such as swimming or biking, usually do not aggravate the pain and can be performed without limitation. Applying home therapy protocols such as ice and/or heat over the knee often do not help address the problem. The pain usually settles down shortly after exercise is completed, but some patients do report ongoing pain with walking for 1-2 days after exercise.
When this type of clinical picture presents during a consultation, I immediately start to question the patient as to what has changed in their daily activity and exercise regimens. When injuries occur gradually, compared to an acute onset that brings pain on immediately such as a sprained ankle, we have to try to identify what factors would have led to dysfunction in the body. Injury doesn’t occur without a reason behind it. When pain builds gradually, it usually means that something has led to the body not being able to accommodate that change from a functional movement perspective. The possibilities of such changes are endless – changes in footwear, in training intensity, in training volumes, in training terrain (road vs. trail running), in the body’s hydration, and changes in activities of daily living, such as an increase in sitting throughout the day. Any and all of these factors can lead to a new stress on how the body moves, which can eventually lead to dysfunction in the tissues, such as the muscles, fascia (connective tissue), and joint capsule. Once dysfunction develops and goes unaddressed over a period of time, the body is at increased risk of developing pain and injury.
When it comes to knee pain as it relates to hip dysfunction, the most common scenario that I see in clinical practice is dysfunction with the gluteal muscles (medius and minimus) and/or the hip rotators. These tissues, located in the bottock and help support that hip while that leg is planted on the ground. They often gradually become tight with biomechanical stress to the area, which eventually leads to tissue contracture, adhesion to the adjacent tissues, and functional weakness due to the tissues inability to contract normally. What’s unique about this scenario is that the patient is often unaware that the problem(s) is occurring around their hip. Upon examination, there is usually very little pain reproduced or dysfunction identified at the knee through orthopedic testing and palpation. However, as soon as we assess the muscles supporting the hip, the patient jumps off the table with pain on palpation (touching the tissue). The patient often reports doing very little maintenance protocols for the hip, such as stretching, strengthening and/or foam rolling. Although this muscular dysfunction is what I most commonly see in practice for this injury, patients can also present with sacroiliac joint irritation (tailbone pain), hip flexor tendinopathy (pain in front of the hip), or hip capsulitis (inflammation of hip joint capsule), all related to gradual dysfunction due to biomechanical stress/change at the hip.
You may be asking WHY does the problem at the hip lead to knee pain. I like to describe this situation as the knee being the innocent bystander and the hip being the true culprit. Biomechanically, the knee joint is a hinge joint that mostly flexes (bends) and extends (straightens). It is located between two much more complex joints – the ankle and the hip. With weight-bearing exercise, where the weight of the body is loaded on the entire lower limb, the ankle-knee-hip complex is considered a closed-chain system. This means what happens at the ankle joint has an impact all the way up the leg, as far up as the low to mid-back, and vice versa. So how does this cause the hip to affect the knee? When dysfunction builds in the structures around the hip, such as the hip rotator muscles, this causes a change in the femur’s (upper leg) movement pattern either due to a restriction in movement from tissue contracture or excessive movement from inhibited (weakened) muscle activity. This change in femur movement now causes the innocent knee joint to start to move abnormally, with an increased rotational stress at the knee, leading to pain due to aberrant movement. This is often referred to as patellofemoral joint syndrome. In this case, the solution is to address the dysfunction at the hip, and the symptoms at the knee will correct themselves.
I take a multi-modal approach to the treatment of this type of injury. Depending on the case, I apply therapeutic modalities over the hip, such as interferential current and laser therapy, to address pain, inflammation, and to desensitize the tissues prior to manual therapy. Once that is completed, we address the tissue dysfunction with manual soft-tissue therapies, such as Active Release Techniques®, to restore the normal mobility to those structures. Home care protocols such as icing, heat, stretching, and/or foam rolling are prescribed. Once the tissue function/mobility has been restored and knee pain has significantly been reduced, a strengthening program is prescribed to help protect the area from future recurrence of the problem(s). Continued stretching is critical and the patient is educated on how to safely introduce change to their training regimen going forward.
Patients are commonly very frustrated with this type of injury as they are often trying to address the problem at the knee, where the true issues lie higher up at the hip. If you think you are experiencing this type of problem, introduce regular stretching for the hip and buttock. If that does seem to address your knee pain, seek help from a healthcare provider to assess and diagnose the problem. Although this may seem to be a complex issue, addressing the source of the problem often helps resolve the issue effectively and quickly.