The popularity of running is ever-increasing. Whether it is for health and fitness, recreation, competition or stress reduction, it is a fantastic, inexpensive way to expel energy and enjoy the outdoors. Due to the impact and the repetitive nature of running, unfortunately there is a high injury toll associated with it especially involving the knees. Patellofemoral pain syndrome is an extremely common injury complaint of runners. As Physiotherapists we understand the importance of exercise in a healthy lifestyle. Our aim is to work with you to help you achieve your goals and to keep you running for as long as possible, by addressing any potential risk factors for injury.
Patello-femoral pain, also known as anterior knee pain is one of the most common injury complaints of runners (Chumanov, et al. 2012). Patello-femoral pain (PFPS) is often felt under or around the knee cap at the front of the knee. The pain usually worsens with activities such as going up or down stairs or hills, squatting and running. It is considered to be an overuse injury and is significantly more common in females (Willson, et al. 2012). There are several factors that can contribute to the development of PFPS. Therefore, often treatment needs to be a multifaceted approach.
The patello-femoral joint is the joint between the patella (knee cap) and the femur (thigh bone). The patella sits on a groove at the bottom of the femur where it meets the tibia to form the knee joint. When the knee bends and straightens, the patella glides up and down this groove. The quadriceps is a group of four muscles, (rectus femoris, vastus lateralis, vastus medialis and vastus medialis obliquus). They are attached to the patella by a tendon and this tendon extends over the patella onto the tibia. The job of the quadriceps is to straighten the knee. We rely on the four muscles of the quadriceps to work together and balance each other out to maintain the central position of the patella in its groove on the femur. The hip and ankle also have a large impact on the function, position and the loads through the knee joint.
Factors that have been found to contribute to PFPS can be external and internal. External factors present in running that may increase the risk of PFPS include training habits and the surrounding environment (e.g. running surface). Internal factors of the runner may include the posture of the foot, the reaction times of the quadriceps muscles, tightness of the muscles that attach to the ITB and the hamstrings and weakness of the gluteal muscles (Kwon, et al. 2014). The internal factors affect the quadriceps angle (Q-angle), rotation of the femur and tibia and tracking of the patella. This subsequently can lead to abnormal or excessive loading on the patello-femoral joint and eventually can lead to pain. These can all affect how the patella glides on the femur.
It has been found that lack of hip strength is associated with PFPS (Taylor-Haas, et al. 2014), particularly in females. More specifically it has been found that females suffering from PFPS have reduced strength in hip abduction, extension and external rotation of the affected side (Prins & van der Wurff. 2009). The muscles responsible for these movements are known as the gluteal muscles. This can lead to rotation of the femur inwards while running. Similarly, overpronation of the feet, which means the feet roll in too much can also lead to rotation of the lower extremity and change the loads through the knee joint.
Hamstring tightness is another factor that has been found in many people suffering from patellofemoral pain. It is thought that tightness in the hamstrings means that the quadriceps muscles need to work harder to extend the knee. This can lead to increased loads being placed on the knee cap to extend the knee (Kwon, et al. 2014).
Changes in the work of the quadriceps muscles have also been found in people suffering from PFPS. The vastus medialis obliquus (VMO) is the stabilising muscle of the knee joint and counterbalances the force of the vastus lateralis (VL) while extending the knee. It is not known for sure why these changes occur and which factors have the most influence in the development of PFPS. However, the quadriceps angle and the increased internal rotation of the femur can lead to tightening of the VL. Like the other core stabilising muscles of the body when there is pain the VMO becomes dysfunctional and has been found to have a delayed reaction time. This can mean that the patella has unbalanced pulls from the VMO and VL during movement and can lead to changes in the loads through the patello-femoral joint, with more force pulling towards the outside of the joint.
Over-training is commonly associated with overuse injuries such as PFPS. This can be due to overloading the musculoskeletal system without adequate preparation (e.g. too much too soon) or not allowing the body sufficient time for recovery between training sessions. When starting a new sport or activity it is important to take a graduated approach this is to allow your musculoskeletal system to adapt and become stronger to cope with the demands of the activity. Recovery time is an essential component of the adaptation process. If the recovery time is too short, this can lead to overloading of the joints and breakdown of the tissues in our body. When we exercise our muscles, tendons and bones break-down in response to the new load and then rebuild themselves to be stronger to cope with the new stresses. It’s through this process of adaptation that our body becomes stronger in response to activity. If there is not enough time allowed for the rebuilding phase it can lead to the breakdown of the muscles, tendons and bones and can lead to pain and injury.
The running surface is also an important factor to consider when starting a running training program. Running up and down hills are going to change our running style and place different demands on the body than running on flat ground. Certain muscle groups such as the gluteals and calf muscles have to work harder going up hills. Going down hills, the muscle system has to work hard to control your descent and prevent you from falling, it may not feel like it at the time but this can actually mean the muscles have to work at greater levels to slow us down. The impact through the joints may also be greater. Similarly, when running on uneven surfaces this may also cause a change in the running pattern. Therefore, if you are training for a particular event, it’s important to take into account the type of surface, and the terrain. Or if you are already running, a great way to challenge yourself may be to add some hills into your program, however make sure you ease into the new challenge.
When starting a running program it is important to make sure that you have appropriate footwear, a sensible training schedule with a graduated progression of distance and intensity, with appropriate rest breaks. Plan a running route taking into account the surface, hills and terrain of the environment. If you are experiencing any pain in the joints, muscles or tendons it is important to address this with a Physiotherapist to have your biomechanics assessed to make sure the injury doesn’t progress and to prevent further injury and dysfunction.
At Q Pilates we are a group of experienced Physiotherapists that frequently assess and treat people suffering from all sorts of injuries including PFPS through exercise. We perform a thorough assessment to ascertain whether there are any potential risk factors for injury. We then design a graduated program to address any issues with strength, flexibility or mobility. We also provide ongoing advice and education and support to help you achieve your goals. We welcome anyone who wants to start a running program and would like a little guidance, if you want to increase your running program and want to train your body to be able to manage the next step or if you may be suffering from an injury that is hampering your ability to train. We strongly believe that exercise is an essential part of a healthy lifestyle and aim to keep you running and playing sport for as long as you desire.
Chumanov, E.S., Wille, C.M., Michalski, M.P. & Heiderscheit, B.C. Changes in Muscle Activation Patterns when Running Step Rate is Increased. Gait Posture 2012; 36 (2): 231-235.
Kwon, O., Yun, M. & Wanhee, L. Correlation between Intrinsic Patellofemoral Pain Syndrome in Young Adults and Lower Extremity Biomechanics. Journal of Physical Therapy Science 2014; 26: 961-4.
Prins, M. R. & van der Wurff P. Females with Patello-femoral Pain Syndrome have Weak Hip Muscles: A Systematic Review. Australian Journal of Physiotherapy 2009; 55 (1): 9-15.
Taylor-Haas, J.A., Hugentobler, J.A., DiCesare, C.A., Hickey Lucas, K.C., Bates, N.A., Myer, G.D. & Ford, K.R. Reduced Hip Strength is Associated with Increased Hip Motion during Running in Young Adult and Adolescent Male Long-Distance Runners. International Journal of Sports Physical Therapy 2014; 9 (4): 456-467.
Willson, J.D., Petrowitz, I., Butler, R.J. & Kernozek, T.W. Male and Female Gluteal Muscle Activity and Lower Extremity Kinematics during Running. Clinical Biomechanics 2012; 27 (10): 1052-7.
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