Knee Pain Affects a Large Percentage of the Population

A research article by van Saase et al in 1989 estimated that 30-40% of our population will experience knee pain by the age of 65.  Times have changed, we are more active as a society, and I wouldn’t be surprised if that figure is nearly double nowadays.  One thing is for certain; knee pain continues to be one of the most common and oftentimes misunderstood musculoskeletal problems.  Often times pain arises due to a combination of many factors.  Let’s look at some of the possible causes/sources of knee pain, and the implications for training.

Potential Causes

Specific Structural Causes

This can include an acute injury or derangement such as a ligament sprain, meniscus tear, contusion, etc.  There are many specific structures in the knee that can cause pain, but I will not delve into that.  Other examples of less specific structural causes include patella alta and an increased Q angle.  With patella alta the knee cap sits higher than it should, resulting in a longer than usual patellar tendon and increased susceptibility to dislocation.  An increased “Q (quadriceps)” angle (greater than 15°) increases the tension on the lateral (outside) structures, and encourages the knee cap to track towards the outside of the knee.  This is often seen in women because of their wider hips.

Weak hip musculature

The primary culprits here are the glutes.  Just as the mechanics at the foot can affect the knee, so can the hip.  If the hip abductors and external rotators are not functioning efficiently, the knee will tend to rotate or translate inward during functional activities such as squatting or ascending/descending stairs.  This changes the alignment of the knee and affects how the knee cap tracks in the trochlea of the femur.

Insufficient flexibility

If the muscles/tissues that cross the knee joint are tight they can affect how the knee cap tracks with regards to the femur.  For instance, tight quads can limit the amount of movement of the knee cap because of this muscle’s connection to the knee cap.  A tight IT band can create increased lateral pull on the knee cap, similar to the effects of an increased Q angle discussed above.  Tight calves may limit movement at the ankle and cause increased pronation of the foot (“flat foot”).  Increased pronation of the foot is associated with a rotating inward of the tibia, and therefore affects the alignment of the knee and how the knee cap tracks with regards to the femur (it’s complicated).

Training to Prevent Knee Pain

• Pay attention to your knee alignment: Working out facing a mirror is not all vanity.  It can help you immensely as you focus on alignment.  It is important to maintain proper knee alignment during all exercises.  Two basic rules are:
  • Don’t let your knees translate forward past your toes.  This increases stress on the knee joint.
  • Make sure your knee caps are tracking in line with the middle of your foot.  This promotes efficient alignment of the knee.

• Increase your flexibility: Based on the information above, particular emphasis should be place on the major muscles crossing the knee joint:
  • Quads
  • Hamstrings
  • Calves

• Roll out your IT Band: The IT Band is not a muscle, although at least 2 muscles attach into it near the hip (Tensor Fascia Latae and Gluteus Maximus).  It is a thick band of connective tissue.  Because it is not a muscle, it is very difficult to “stretch”.  Therefore, grab a foam roller and give yourself a deep tissue massage.  You’ll love it and hate it at the same time.
• Strengthen your hips: If your glutes are weak you are setting yourself up for failure.  Pay particular attention to hip abduction and external rotation, as these movements play an integral part in efficient knee alignment.
• Strengthen your core: If your trunk is weak, you have no foundation from which your legs can efficiently move and carry your weight.  Forget about the six-pack and focus on the deep stabilizing muscles (transverse abdominus, multifidus, internal and external obliques, and pelvic floor).

There are obviously certain things that exercise alone cannot change, such as some of the structural causes of pain mentioned above.  But, for the general population, these principles can help prevent knee pain or rehabilitate a painful knee.