Knee pain is the most common running injury. It results from the forces on the knee exceeding the tissues ability to tolerate stress. It is associated with training errors- doing too much, too soon- as well as limitations in strength and coordination of the hip and knee. In this article, I will highlight assessing and treating your knees to get you back on the right track.
The first step to assessing the knee is to address the muscles in front of the thigh, the quadriceps. Weakness in this muscle group is a major factor for the development and/or persistence of anterior knee pain. Strengthening of the quadriceps is a foundational intervention in rehabilitation of the knee.
Here are my simple tests for muscle activation, and strength. If you have pain with these actives then consult your local physical therapist. If any of these are challenging, then the test simply becomes the exercise. Changes can be expected quickly in 1-2 weeks with some of these drills!
Quad setting
Straight Leg Raises
Squats
Single Leg Rises
Do you know how much stress goes through the knee while running? 2.5x Body Weight… In order to rehabilitate or prepare a runner with knee pain for these forces we need to progressively load their muscles and joints. Loading these tissues through exercise begins with activities that produce produce a tolerable amount of stress. As the body adapts to these stresses, then the forces with exercises are progressed. With improvements in the body’s capacity to tolerate stress a person with knee pain will progress from not being able to walk to eventually running a 5k.
Here is an example of a scale of exercise from low to higher knee forces:
Walking = 0.5 x body weight
Step up 60deg= 2.5 x body weight
Squat to 60 def= 3.5 x body weight
Single leg squat= 4-5 x body weight
The knee moving in is an example of hip adduction
There is a strong association with knee pain and the presence of excessive hip adduction and pelvic drop. Both of these movement issues can be identified by watching someone run, walk or perform activities on a single leg. The first step in improving the knee's ability to tolerate stress is to begin by strengthening these muscles.
Try these simple tests for coordination and strength to see if addressing this area is worthwhile:
Single leg standing for 30 seconds with trunk and pelvis alignment
Single leg squat for 6 reps with good control
Sidelying hip adduction for 25 reps without fatigue
If any of these are challenging, then the test simply becomes the exercise. Changes can be expected quickly in 1-2 weeks with these drills!
Once the knee is tolerating stress without any negative consequences(pain) then we can start back running. Some folks may benefit from the specific treatment of their running form to cut down on the stressors on the knee. The 2 major ways to do this with a PT is to alter cadence or to change alter running mechanics to improve positioning/ alignment of the lower extremity.
First, we must identify abnormal mechanics that may be leading to excessive stress on the knee. This is typically excessive knee adduction(knock kneed) or a pelvic drop(see above). Then we facilitate a change through coaching. When training running gait to improve form running form the most simple cues have the best effects: “keep your knees apart” or “squeeze your glutes” are my go to’s to improve thigh position.
In summary, knee pain can be limit activities we love to do like running, lifting, dancing, etc. There are almost always things we can do in physical therapy to get you to move better then move more. Look to strengthen the hip and knee. Alter some movement biomechanics as needed with running or lifting. Then work hard and be consistent. You will be back to do doing what you love in no time!