Anterior knee pain is commonly described as knee pain under or immediately around the knee cap (patella), more typically on the outside (lateral) aspect of the patella than the inside (medial). This pain pattern typically arises from irritation about the patella on the underlying thigh bone (femur). This type of problem is one of my favorite Physical Therapy problems to evaluate as there can be multiple contributing factors.
Typically, individuals who develop anterior knee pain from non-traumatic causes can generally attempt to self-treat by strengthening and stretching the quadriceps muscle. This can often help the pain as weakness or decreased flexibility may be the primary cause for developing pain. If you attempt to self-treat, I strongly recommend that you do not perform exercises that recreate your pain, either at the time of the exercise or following the exercise. Knee extension weight machines generally increase pressure in this region and often should be avoided. Having pain and burning in the muscles that you are working is a positive thing and should not be considered pain when treating this type of dysfunction.
If simple quadriceps stretching and strengthening is noneffective in improving pain or if you are unable perform these exercises without joint pain, then it is time to consider treatment from a physical therapist. Your physical therapist can assess the strength, flexibility, and biomechanics of the foot, ankle, knee, patella articulation with the femur, hip and core (back and stomach). In Part 1 of this blog I will address how patella alignment can contribute to knee pain.
The patella is a floating bone that is imbedded in the end of the quadriceps muscle from above and connected to the shin bone (tibial tuberosity) below by means of the patella tendon. As the patella is connected to the knee only by soft tissues (muscles/ligaments/tendons), there can be a variety of movement from hypomobile (limited motion) to hypermobile (excessive motion). The patella rides in the trochlear groove, a trough, at the end of the thigh bone (femur). The space and weight bearing of the patella within the trochlear groove should essentially be balanced and weight should be distributed equally across the patella as the knee bends. Individuals with anterior knee pain may have alterations to the balance or alignment of the patella. When this occurs, the patella is typically tilted toward the outside of the knee, however, the patella can potentially tilt or rotate in many directions.
These positional abnormalities often can be improved through specific strengthening or stretching exercises to help restore balance to the patella. Taping the knee can mechanically pull the patella into better alignment. Kinesiotaping can help to facilitate muscle contraction to assist with patella alignment as well. One might consider patella malalignment like a car being out of alignment. When this happens, your tires wear unevenly and need to be replaced more often. For your patella to track properly you must stretch tight tissues that pull the patella out of alignment. Conversely, a weak tissue that cannot hold the patella in proper alignment needs to be strengthened.
Knowing specifically what tissues to stretch and strengthen varies from person to person. To ascertain a patients’ specific anterior knee dysfunction, a physical therapist can evaluate specific patella alignment characteristics and determine contributing tissue tightness and muscular weaknesses. In my next blog, I will discuss how joints above and below the knee can impact anterior knee pain.
Written by: Michael Hoag, PT, DPT, MBA, OCS, MTC
Over his next several posts, Michael will discuss how mechanical dysfunctions at the hip, knee, and ankle as well as weakness, tightness, or abnormal alignment and biomechanics can contribute or cause anterior knee pain.