Runners Knee – Presentation and Treatments
Many of the people we see present with what they call ‘runners
knee’. This is classically a pain in front of the knee cap that comes
on during a run and can stay for a period of time afterwards. A
quick internet search leaves me feeling quite confused as the first
three sites I looked at all gave a different description of ‘runners
knee’. So we can take it that ‘runners knee’ is a collective term
relating to any pain in the front of the knee that comes on when
you increase your activity – and running will do this if you are
increasing your training. So what follows is a quick look at some
of the common presentations and what you can do about them.
This is based on a case study of someone who I saw recently
who, so far so good, is doing OK and back into his running and
building mileage again.
A Brief Explanation of Runners Knee
The general feeling is that the pain is usually behind the knee cap and a result of poor alignment of the knee cap as you
straighten your leg into the push off phase of running. Although other sites say it is caused by the strain tendons or
ligaments put onto the knee cap.
Below we can see an image of some of the many problems that can be attributed to knee pain.
As you can see there are quite a number of different things that causes knee pain. It is important to try and ascertain a
correct diagnosis – what is it that actually hurts? Secondly to this you really need to understand why it has happened the mechanism of injury. This is crucial to ensure that you have the correct treatment and you address all the issues that
may be a factor in the development of your injury.
Treatment advice from the above mentioned websites involves: (ready for this) resting for a period of time, sorting out
the balance between hamstrings and quads and stretching and / or strengthening as required following a check from a
physio who understands these things, checking footwear hasn’t worn out, anti-inflammatory medication and some sites
even recommend orthoses if you have ‘over pronation’.
But not one of these sites mentioned having your running style checked. From our point of view (which is a functional
approach) this is essential as we feel that the reason you may have a muscle imbalance, are wearing your shoes
unevenly or have any muscle strength/flexibility issues is due to the way you function.
So as well as offering all of the above we endeavour to find out why you are putting unwanted pressure on the front of
your knee cap, not allowing it to track properly, creating a muscle imbalance between your hamstrings and quads or
wearing your shoes unevenly. This will come in the form of gait analysis with the aim being to find out how and why you
are functioning the way you do and what you need to do about the findings. To ensure that we really can give you the
best information we resort to technology for this; high speed video and in shoe pressure analysis.
So, what do we do?
We do a non-weight bearing and standing assessment to check alignment of feet and limbs. We look at your overall
posture and check for muscle weakness or tightness in all muscle groups that are involved in walking and running. We
can arrange for a physio/sports scientist to undertake a functional movement assessment to ensure that we provide a
thorough analysis all in one go. We will then put a very small insole into your shoe and link this to the computer.
We then film you running with a high speed camera (usually at 240fps) on the treadmill and take a reading of 10-12
footsteps from the in- shoe sensors. This provides much more detailed information than a mat scan. This is because it
shows both the interaction of your foot with the shoe and also how the shoe is reacting to your foot. It also shows how
your body weight is moving over your foot. If you wear orthoses we can also see the effect these are having on your
function. Orthoses should always be prescribed to do a certain job and this in shoe pressure system will tell us if the job
we want them to do is actually happening. So if you wear orthoses make sure you understand what it is they are
supposed to be doing to your feet and the effect this is going to have on the rest of your body. The same applies to
footwear that you have been sold from a running shop that has carried out a gait analysis. Ensure that you know what
the effects of the shoe and / or orthoses are supposed to have on your body, posture and most importantly the way you
function.
So what about our runner who came to see me regarding his increasingly frustrating knee problem?
He has been troubled with knee pain for a couple of years now and came to me following frustration with his GP about
not referring him for a MRI scan. He presents with the usual symptoms of pain in front of the knee when running and it
gets so painful that sometimes he has to stop and sometimes he can run through it. He is aware that things are not right
and wants it sorted so he can continue to train and not cause long term damage to his knee.
So after the foot, alignment and muscle check we wired him up and sent him for a run on the treadmill. Here is what we
found: (the images from the video footage go from left to right)
The video clip stills show a number of things;
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1. Midstance show a slight anterior rotation of the pelvis, feet are fully pronated and body at lowest point,
sitting back posture with forward lean of upper body at hips evident.
2. Propulsive phase – this photo shows point of maximum extension of limb, pelvis has rotated forward –
this means no stretch of hip flexors or quads, shortening and compression of lumber spine and poor
function of muscles, arm swing across chest and hand very high.
3. Toe off, knee flexed at this point, further rotation of pelvis, swing leg fully extended, hand further into
chest, maximum vertical height. This means that from picture 2 to picture 3 the knee is flexing whilst the
foot is still in contact with the ground and will therefore be losing propulsion power at the foot and
transferring propulsion to an exaggerated swing phase from the hip flexors and quads. Therefore there will
be little lift and drive from either hamstrings or calf muscles. Also there will be increased compression of the
knee cap against the femur during this phase of his gait cycle.
4. Contact position - upper body position is forward leaning at the hips and will therefore create a natural
heel contact in an over stride position. This creates a high impact force on a straight leg and ‘piked’ body
position.
There is lots of talk about- which bit of the foot should contact the ground first with the mid or forefoot being touted as
being the best. Well think about it a different way and consider where the contact position is in relation to the rest of
the body and the posture of the body over the foot. I still see lots of people who have tried to adopt a mid or forefoot
position and still over stride. Hitting the ground in front of you with a straight leg will always create a breaking force and
a high impact force, whilst a contact position underneath you will aways create a softer, lighter impact force.
So what is happening in the shoe in this situation?
In Shoe Pressure Analysis
The footprints are an average of the steps 2-9 and 2-10 and the white line in the centre is the position of the body’s
centre of mass. The brighter the colour, the higher the force. The graph on the right shows a force / time curve. This
shows how much force is being applied to the sensor at which stage of the contact position.
The footprints show lateral weight bearing and minimal toe weight bearing into propulsion. The Centre of Mass line
shows a forward momentum and then a deceleration into propulsion as the line moves back towards the centre of the
foot when it should continue onto the toes.
The force/time curve shows a high impact peak with the maximum peak force occurring at 37% and 41% of stance time.
The curve peaks very rapidly with a slow drop off into propulsion.
A more propulsive curve would look like the one below.
In this example the curve takes longer to
get to the high point and then drops rapidly.
Also on this curve there is no contact
transient which can be seen on the left foot
(green) curve above – this is showing a
deceleration on the initial impact.
So what can we conclude about how the function is causing the problems with the knees?
There are two factors that are important; the lack of extension of the knee into propulsion and the over stride at
contact. The over stride will be having two effects on the body; firstly there will be high impact forces and the body has
to dissipate these, and secondly the body has to get past the foot stuck out in front of it. The lack of extension into
propulsion is also having a number of effects on the body. The muscles are always under tension as the joints are always
flexed, joints are only being moved through a small range of motion – therefore increased load on a small surface and
tension in the muscles, anterior rotation of pelvis during hip extension – again shortening of hip flexors and quads,
tightening of hamstrings to combat forced stretch (as hamstrings attach onto the rear of the pelvis), there is also the
weak tight hamstrings and overactive and tight quads that we often see in runners knee presentations, increased curve
in lumber spine – muscles not able to function in correct manner, not able to push strongly on foot and so generate a
pushing force from behind and having to lean upper body forward at the hips to overcome a lot of the above.
We can see that there is a link between function and anatomy; tight muscles cause the knee to stay bent at propulsion
but the muscles have to be tight as the knee is bent. What causes what, and what came first? Sometimes we will never
find out. What we do know though is that just stretching out his quads and hamstrings will not sort this issue out, he has
to change his running style to as this is what is causing the muscles to be tight.
From the video assessment we can see the above clearly and how the whole body is involved. This is really useful from a
patient point of view, as we can describe it but if you can see it, it makes so much more sense. This patient went away
with these video files so he can look at them again to remind himself of what he should not be doing.
The in shoe analysis backs up the video footage but provides us with another way of looking at things. The centre of
mass line can be seen to be moving back down the foot, this is a deceleration, this is a waste of energy from a running
point of view. We have worked hard to move our centre of mass forward, we do not want to see it moving backwards!
The force/time curve also provides a good visual idea of what is happening at propulsion, we can see the force line
almost petering out as we head towards toe off. Again this is not using our body in the strongest most efficient manner.
So after discussion of the above what can we do about it? This person really needs to do a number of things. There has
to be a change of running style, footwear needed to be addressed, muscles do need to be stretched ideally from a
sports massage therapist who understands soft tissue release techniques and then backed up with home treatment, we
felt that orthoses would be of benefit – to provide a stable base as the body moves from midstance into propulsion and
ensure that the big toe joint is taking body weight at this stage (we have hardly mentioned big toe joints but it is very
important that these are working but it would be a whole other newsletter to talk about big toes – another time
perhaps), improved dynamic posture from Pilates type worked but mainly based on functional movements not static
ones and also looking at his training runs and getting some variety and focus into his training not just going out and
making every training run a race – which we runners so often end up doing as we want to improve our distance or time
from one run to the next.
So he went away with a treatment plan and, as we already have said, so far so good. Knee pain improving and more
importantly running with focus and feeling as if making progress. He is not local so having to wait a few more weeks
until we can do a review and we can easily check before and after on the video and in shoe pressure data to see if things
are moving in the right way.
If you would like any further information on any of the services that we offer or want to have a chat about your injuries
and show we may be able to help then please contact us. Please feel free to leave some comments.