By Jason Dodd, Lead Sports Massage Therapist and Member of the Sports Therapy and Physiotherapy Team.
Continuing our focus on knee pain and the implications of surgery, this month I wanted to speak with you all about something you may have heard Physiotherapists, Sports Therapists, Osteopaths, Injury Rehabilitation experts, etc…. say when it comes to pain in the knee area from running and that is ‘develop the strength of your Glutes and you will remove the pain in your knee’. As medical professionals we understand the concept of this but we often wonder if our clients have the same appreciation of its meaning.
To start off, there are still some question marks on the importance of your glutes when it comes to managing knee pain. There is no questioning the importance of the glutes in hip stability, hip extension and force distribution when running, but how much impact they can have is sometimes debated. The theory is that weakness in the Gluteal area leads to an increase in hip adduction (the collapse inwards of the thigh bone) as demonstrated by the picture here.
If we examine this topic in 3 main areas we can break it down into muscle timing and duration, muscle strength and what you can do about it.
GLUTE MUSCLE TIMING AND DURATION
This paper here concludes;
“THERE IS CURRENTLY MODERATE TO STRONG EVIDENCE THAT GMED [GLUTEUS MEDIUS] MUSCLE ACTIVITY IS DELAYED AND OF SHORTER DURATION DURING STAIR ASCENT AND DESCENT IN INDIVIDUALS WITH PFPS. IN ADDITION, LIMITED EVIDENCE INDICATES THAT GMED MUSCLE ACTIVITY IS DELAYED AND OF SHORTER DURATION DURING RUNNING.”
Muscle activity that is ‘delayed and of shorter duration’ means that the muscle starts to work later during an activity and contracts for a shorter period. But how easy is it to measure this? Without machines known as EMG’s it is near impossible to identify this. BUT, what is clear, in theory, is that if the gluteal muscles activate later and for a shorter period with every foot strike they provide less support to the leg and this can lead to an increase in hip adduction (the collapse of the leg inwards like the picture above) and therefore greater stress on the knee area. With thousands of foot strikes occurring during a run this then becomes quite a big factor to be aware of.
GLUTE MUSCLE STRENGTH
Glute strength is said to be one of the most important factors in avoiding knee pain, especially when running. this study here looked at the relationship between strength and hip adduction angle during running. It concludes;
“RUNNERS WITH PFPS DISPLAYED WEAKER HIP ABDUCTOR MUSCLES THAT WERE ASSOCIATED WITH AN INCREASE IN HIP ADDUCTION DURING RUNNING. THIS RELATIONSHIP BECAME MORE PRONOUNCED AT THE END OF THE RUN.”
Interestingly, the relationship appeared to be more prominent in women than men.
A follow up of this work here identified three distinct subgroups of running characteristics in people with knee pain. They were; increased knee valgus (knee collapse inwards), increased hip abduction (where the legs rotate outwards TOO much) and the typical knee and hip adduction (knees and hip coming inwards when running). What this highlights is that there is a wide variety of possibilities of what could be causing knee pain and that it is hard to offer just one recommendation to any one person.
The issue we have here though is that we have summarised a couple of points but research has shown there to be over 500 factors that are thought to contribute to this pain!! The above points are just a snippet of hundreds of research papers on it.
We can sit here and talk about possible theories all day but the main question is…
WHAT CAN YOU AS AN INDIVIDUAL DO ABOUT IT?
First off, we would highly recommend you see your Physio or medical professional about what may be causing the pain so they can determine if your Glutes are playing an important part in the pain you feel. We have also produced a blog here on ‘The best exercises for developing Glute strength based on research and evidence’
If glute weakness is found then there are several exercises that have been shown to improve knee pain and reduce joint loading. These two examples below have both been shown to reduce symptoms in as little as 4 weeks in some cases.
The single leg squat, as indicated here in this research paper has been shown to be a reliable tool in examining hip muscle function in those with knee pain.
What is really important but often overlooked is the use of weight bearing exercises. This research paper shows the forces that can run through just the Achilles tendon (Soma CA, Mandelbaum BR. Achilles tendon disorders. Clin Sports Med. 1994;13:811–23). The paper shows that 8 times the athletes body weight can pass through this tendon on each foot strike. A suitable and thorough strength programme then designed to accommodate high loads is recommended but you must be cautious of which exercises you choose as they can sometimes aggravate knee conditions, especially if performed with poor technique.
As the symptoms settle and become less irritable then a more developed and well rounded programme can be introduced. This paper here showed improvements in hip and knee joint mechanics which could reduce load on the knee area. The programme they used is highlighted here below;
It should be noted here though that this programme used healthy subjects and not those with knee pain so it is advised to be cautious before undertaking anything like this. It is also worth noting that these exercises above may not change hip position and several studies have shown that reduced pain can be achieved without a change in hip adduction (leg collapse inwards) during running. To improve your hip position during the gait cycle you may need to work on your running style, but that is for another time!!
To summarise: It is fair to say that there is a link between gluteal muscle function and knee pain, especially in women. This is not to say though that the knee and its mechanics should be ignored. Exercises aimed at developing the gluteal area can improve pain in running but may not necessarily.