The information provided is based on up to date scientific research to the best of my knowledge. This article will be followed by a more succinct version for a quicker recap. I have attached several Graphics and Articles, so click the Highlighted Words for a better understanding.
The Whats and What Nots!
Part 1 / 3
Running is a fantastic means of keeping fit and has many health benefits for the heart, body an
d mind.1 However many of us suffer setbacks in our chase for the Runner’s High. Each year, injury affects up to 50% of runners 2, the majority of which are from overuse, with the knee being the most affected.3 Contrary to this, Running is Not Bad for your Knees. Pain can be an uncomfortable setback, but should be seen as motivation to address the issue early so we can return to enjoying our running pain free.
A.K.A: Patellofemoral Pain Syndrome (PFPS from here on), Anterior Knee Pain.
PFPS is characterised by pain felt around the knee area, worsened by repeated use. The pain may begin quite mild but can progress to affect your daily activities. Despite the name, Runner’s Knee can affect a variety of athlete types. PFPS is not related to a specific injury, rather it is a group of symptoms resulting from several possible causes. Due to this, no single Surgical or Rehabilitation Protocol will be effective for everyone. It is important to understand that Pain itself is not the problem, but an indicator that there is a problem. Treat the Cause, Not just the Symptoms.
PART 1: CHALLENGING CONVENTIONAL WISDOM
The history of PFPS is muddled with a multitude of possible theories, causes and treatments. Throughout the years these theories have been re-investigated and revised to further help identify significant and insignificant factors, some of which will be discussed here.
Degenerative Changes, Scans and Surgery:
Most changes in structure of the knee as seen on Scans (Xrays, MRIs) are now considered to be Normal, as they are very common even in healthy, pain free individuals. This includes Chondromalacia Patellae (Cartilage degeneration), Meniscal Tears and findings commonly considered Osteoarthritic changes. Scans can often create a one dimensional attitude towards the source of Pain, by identifying a ‘faulty’ structure which then becomes the primary concern of the runner. This may lead to worse outcomes by reinforcing a Thought Virus that ‘My Knee is Damaged’, leading to increased anxiety and subsequent pain.4 Surgery might then be considered to fix or remove the ‘faulty’ structure. However, because these changes are normal, Surgery is an unnecessary and costly intervention, and is also an INEFFECTIVE treatment of PFPS.5
Where is my pain coming from?:
One author investigated the pain response of his own knee by inserting an arthroscopic needle into the joint to stimulate various tissues without analgesia. He then rated his level of pain sensitivity and attempted to identify the location of the stimulation.6 What he found was that the surrounding soft tissues had the greatest sensitivity and were most accurately localised. Other structures had a much lower sensitivity and were poorly localised. Most interesting was that the Patellar Cartilage showed no pain sensitivity, even though Chondromalacia Patella was present. Other research suggest that the nerves themselves may be the pain generating tissues, becoming enlarged 7 and increased in number 8. This may be due to ongoing stresses on the knee due to poor Biomechanics or Muscular Imbalances.
Patella Maltracking + Position Faults:
Patellar positioning or mobility issues within its groove have been theorised as a cause of PFPS, resulting from muscle imbalances around the knee (weak inside, tight outside). To address these issue, specific exercises were designed to strengthen the Vastus Medialis Obliquus (VMO) on the inside of the knee and to reduce the tension of outside tissues. The research has refuted this theory in a number of ways. Patella tracking and positional ‘Abnormalities’ are common and may even be Normal.9 It is questionable whether the VMO actually exists as a separate muscle to the Vastus Medialis (VM)10, and if exercises can even target the Inner Quads over the others.11 It is true that VM timing is delayed in PFPS 12, but this is most likely as a result of Pain and Swelling 13 rather than the cause of it. ‘VMO-specific exercise’ have been shown to improve symptoms of PFPS however this is likely due to a general increase in Quads strength, and not due to specific changes of the VMO.14
Summary of Challenging Conventional Wisdom
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Ruairi o Donohoe Chartered Physiotherapist