Knee Pain

Knee pain is an all too common complaint in runners. There are many causes for this knee pain but one of the most common injuries is called Anterior Knee Pain (AKP) or patellofemoral pain syndrome (PFPS). This makes up to around 25% of all identified knee injuries in runners. The interesting problem with AKP is that it is a diagnosis made from its only symptom of pain which is usually located around or under the knee cap. This condition is rarely associated with any structural damage.

Historically we used to think that one of the primary causes of AKP was due to the misalignment of the patella during running. Clearly there is an association between tight and overactive structures around the knee that can influence the position of the patella through its movement. Addressing these through a structured stretching program and a course of manual therapy can help. However, more recent research is shedding new light on the most common cause of AKP. Hip weakness and early fatigue during the stance phase of running leads to a valgus or ‘knock knee’ posture and this has shown to be a leading cause of AKP. Simply put, as your foot comes in to contact with the ground the muscles on the outside of your hip must become active to stabilise the pelvis girdle and to stop it tipping forward on the opposite side. If the muscles do not do this then your knee will turn in slightly (genu valgum) to compensate causing a change in the biomechanics and probable pain around your patellar! Studies have shown that by incorporating specific hip abductor strengthening exercises in to a rehabilitation program, not only does the peak hip abduction strength improve but stride-to-stride knee joint variability improves, a reduction in genu valgum is observed during stance phase and most importantly pain is reduced!!!

So what is a good exercise to improve your lateral hip muscles? Well my 2 favourites include the resistance band walk and the lateral shuffle. All you will need to do these exercises is a loop of resistance band and a bit of space. Loop the band around your lower leg or ankles and stand in a half squat position with your feet wide enough apart to feel some strong tension in the band.

  1. To do the resistance band walk all you do now is walk forward in the half squat position keeping the tension in the band by making sure your feet stay wide apart. Take around 20 steps forward and then 20 steps backwards.
  2. To do the lateral shuffle, instead of walking forward in the half squat you take a step to the right keeping the half squat and after planting your right foot you move your left foot equal distance to the right. Take around 20 steps in each direction.

There are many more exercises that can help improve your function and running form and so if you would like a comprehensive assessment and rehabilitation program developed using the latest in evidenced based research then please do not hesitate to contact us for an appointment.

 

Nick Williams

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Running Cadence

Recently there has been a shift in focus away from particular foot strike patterns relating to running injuries toward alterations in cadence.  While this has been a positive initiative for many runners, foot strike patterns may still have relevance in treating specific injuries.  However, altering cadence is something almost anyone can attempt and adapt to.  Shifting foot strike patterns can be more difficult.

Cadence refers to a runner’s stride rate.  Combining stride rate with stride length gives you your running speed.  It has been suggested that a cadence of 180 strides per minute is optimum.  However, in practical terms this is not relevant as cadence changes with running speed.  For example an elite runner may do an easy run at a cadence of 170 and race a 10 k with a cadence over 200.

10689830_758602744178513_8401221313807836078_nNovice runners tend to run at much lower cadences.  Coupled with lower cadences is the tendency to overstride.  Overstriding occurs when your foot contacts the ground in front of your centre of mass.  This often coincides with heel striking.

So what are the benefits of running with a higher cadence?  Research has indicated an increase in cadence can result in a decrease in force applied to the knee (patellofemoral joint) and hip when running.  Most agree this is do the foot contacting he ground beneath the body’s centre of mass.  The potential downside of this is an increase load to hamstrings and rectus femoris (quadricep) musculature.

To calculate steps/minute, count the number of times one foot strikes the ground for 30 seconds and then multiply this number by 4.  Re-test number of times in various situations.  If your cadence is consistently low (e.g., less than 160), try increasing your stride rate by 5-10%.

Remember, don’t get caught up in the absolute number relating to cadence.  If you are struggling with injury or a novice, it may be worth altering your cadence by a small percentage and see whether it helps.