Lee Herrington qualified as a Chartered Physiotherapist in 1990 from Manchester University, United Kingdom, having previously completed a degree in Human Biology from Loughborough University. In 1996, he was awarded an MSc in Sports Injury and Therapy from Manchester Metropolitan University.
Lee is lead clinician at the Knee-Rehab UK knee rehabilitation clinic and, amongst his many accolades, has worked with elite athletes for the last twelve years, including time with Great Britain Rugby League and Wigan Warriors Rugby League Club.
Here, Lee Herrington talks to PhysioRoom.com and provides an insight into the latest thinking for Physiotherapy treatment of ACL injuries that don't have surgery.
What is functional instability of the knee?
"Functional instability of the knee is when the knee either gives way, or probably just as significantly, there is a perception that the knee is going to give way, during activities involving landing, or twisting/cutting (changing direction) when running.
"This is related to the knee usually going into a position of hip flexion, adduction and internal rotation (you are twisting your thigh inwards) whilst at the same time the knee is flexed (bent) with the tibia externally rotated and abducted (planted foot pointing towards 'two o'clock'). Because of the absence of the ACL, and an often concurrent laxity in the medial collateral ligament, the knee in essence subluxes (partially dislocates) under these loading directions.
"For physios, if you think about it, the position of the knee is very similar to the position when undertaking a pivot shift test for ACL integrity, a positive here being either a subluxation of the tibia or the patient's apprehension of that subluxation. This position in which the knee demonstrates instability is very significant, as will be seen later."
Is it possible for someone who has had an ACL tear to return to sports such as football without have ACL reconstruction surgery?
"The short answer is yes, many players have continued to play without an ACL, in both football and rugby (Herrington 2004 Physical Therapy in Sport). One of the holy grails of ACL research at the moment is identifying those tests which enable you to identify those individuals who will cope without an ACL and those who will not.
"At present the research is far from conclusive but there are a couple of factors which may influence the chances of success. The first is the integrity of the medial collateral ligament (MCL); if this is lax it is unlikely that the patient will cope functionally without the ACL. A second important factor is the proprioceptive ability of the patient. If they have a major deficit in joint position sense (Physio note - error score greater than 10 degrees) they are likely not to be able to cope.
"Joint position sense can easily be measured in the clinic. Get the patient to close their eyes and passively take their knee to a certain angle of knee flexion (measure it with a goniometer) and then get them to reproduce that angle. The difference in angle between the actual angle and the target angle gives you their error score.
"Another proprioceptive related factor is the amount of 'postural sway' that they have. Postural sway is the degree to which people deviate from upright when they are balancing. Again this is easy to test. Stand the patient on one leg (knee straight), hands on pelvis and see if they can keep their balance and how much they wobble about. Repeat this with the knee flexed to 45°. Obviously, with this test the greater about of movement the less control they have so the increased likelihood of non-coping."
What are the goals of physiotherapy treatment in patients with ACL tears that lead to functional instability?
"If we remember back to the motion which causes the perception of actual functional instability it is one of hip flexion, adduction and internal rotation (twisting the thigh inwards), whilst at the same time the knee is flexed (bent) with the tibia externally rotated and abducted (the planted foot at the 'two o'clock' position). This is not a normal position!
"However, this position may be common during sport and is commonly the reason an ACL deficient knee gives way or feels like it will give way. The aim of rehabilitation is to teach the patient to control this movement or, more correctly, collapse into this position. This will involve strengthening muscles and relearning appropriate movement patterns under increasing loads."
What are the best exercises to improve functional instability of the knee in patients with ACL tears?
"In order to control the hip internal rotation and adduction, the Gluteals (principally Gluteus Maximus and Gluteus Medius) need to be trained initially in a non weight bearing, then weight bearing scenario. The Quadriceps also need to be strengthened so they have the ability to eccentrically control the knee flexion (bending). These two elements form some part of the ACL prevention training programmes currently available, which are now starting to show some strong research evidence to support them.
"A very good example of one is the Sportsmetrics programme developed by Dr Frank Noyes in Cincinnati, USA (www.sportsmetrics.net). Following the principles of a programme, such as the Sportsmetrics one, along with appropriate Gluteal training would seem to be what is indicated from the research at present and appears, certainly in my experience, to be very effective clinically."
How long does it typically take before patients with ACL tears who decide against surgery, can return to sport?
"The training of these individuals is all about relearning a motor skill and progressively challenging that skill. The speed of return to sport depends on how dedicated they are to their training and how diligent their therapist is in monitoring and correcting it; you do not get a golf swing like Tiger Wood's without a lot of careful practice! This is similar; it involves many repetitions, but typically it will not take less than 6-10 weeks of very dedicated hard word."