Below is a guest post from Physical Therapist Timothy Shanor where he shares some insight on common causes of knee pain from running. I will be following this post with some others on knee pain as well as some information on the injuries that all the readers have voted on in the survey box off to the right. Thanks for reading Dr. Nick’s Running Blog! There is some great info coming this running season!!
Patellofemoral Pain Syndrome Knee pain is one of the most common injuries in runners. Often we can attribute this pain to diagnoses such as patella femoral pain syndrome, patella tendon tendonitis, distal iliotibial band syndrome or knee osteoarthritis. The most common of these in runners is known as patella femoral pain syndrome (PFS). PFS can be defined as simply pain under or around the kneecap. PFS is an overuse injury which is more commonly seen in females than males. The nature of PFS is multifactorial and can include both musculoskeletal and biomechanical causes. Musculoskeletal causes include anatomical misalignment of the kneecap, hip and quadriceps weakness, core weakness and abnormal flexibility. Additionally, the mechanism of running can lead to biomechanical causes that place excessive stress on the knee which include poor running form, increased running mileage and abrupt change in running surface.
Scientific studies continue to prove that abnormal running mechanics, as defined by striking on the heel during the landing phase of running, contribute significantly to increased forces on the knee joint. Therefore the primary focus in the treatment of PFS in runners needs to address the underlying biomechanical breakdown during the running cycle. In my practice, we utilize video gait analysis with a program called DartfishTM to identify abnormal running biomechanics. As previously noted the most common biomechanical pathology I see includes the dreaded combination of heel striking and overstriding. In these cases, specific running drills are required to simply reduce the stride length and encourage a more compacted midfoot landing pattern. These simple modifications in running form have been noted not only in the scientific literature but in my practice to reduce overall joint impact forces of the knee hence reducing pain and improve overall function. Additionally, runners often see a nice improvement in running efficiency and improvements in time.
Once the underlying biomechanical errors have been identified and corrected now we can focus on identifying underlying musculoskeletal weakness and imbalances. I often say in my clinic, “You have to be strong if you want to go long.” Although every runner presents differently, I most commonly see deficits in the hip and core musculature. We are able to identify these weaknesses in the hip and core by simple muscle testing but also by performing specific functional tests for running such as balancing on one leg and performing a step down exercise. Errors in this seemingly simple exercise are proof that deficits in hip muscles exist. In the running cycle each foot should hit the ground roughly 90 times per minute. Each time the foot hits the ground, the leg has to perform a single leg squat so if the muscles of the hip and core are unable to accommodate to the forces of running something will breakdown in the kinetic chain and often it is the knee joint. Most runners with PFS have a hard time performing this step down activity after just 5 or 10 times before a breakdown in form is demonstrated.
The corrections of these musculoskeletal imbalances often include exercises such as balance challenges, lunges, mini squats, straight leg raises, leg presses, bridges, resisted side stepping and side-lying straight leg raises. Early in the rehabilitation program we are cautious to avoid exercises where the knee is flexed greater than 60 degrees to limit increased stress place on the knee joint. Later in the rehabilitation program more advanced exercises including running specific plyometrics are initiated.
In conclusion, the mechanism of PFS is multifactorial therefore the treatment of PFS needs to address all of the factors mentioned. I recommend a comprehensive biomechanical evaluation including a video gait analysis to correct the underlying biomechanical breakdown. Once the landing patterns are modified, we can now work on creating a strong rehabilitation program which includes balance training and strengthening of both the hips and core while improving the ability to perform and master simple functional tests. The combination of pain free running and improvement in efficiency will lead to the ultimate goal of running…..having fun.
Dr. Campitelli is a podiatrist in Akron, OH specializing in foot and ankle surgery with an interest and enthusiasm for running as well as helping runners with injuries. For the past several years he has been treating running injuries in patients by fixing their form and transitioning them to minimalist shoes. Having treated runners with all types of injuries through conservative measures with orthotics and shoe gear changes to reconstructive foot and ankle surgery, Dr. Campitelli has brought what works best and is most current to his practice as well as the Akron and Cleveland running communities.