London, England
Friday 13th April 2012
After months of inconsistent & unseasonal weather, this week has been typical in the extreme for April, with heavy showers providing intervals for the warm spring weather.  This weekend, is a routine mid-April sporting weekend too, with the with the starter's tape lifting on the Grand National tomorrow afternoon & the FA Cup semi-finals taking their traditional place alongside the big race...& no surprise either that Manchester United are back on top of the Premier League table!  Meanwhile the majority of British track & field athletes are immersed in warm weather training camps in Portugal, USA, Spain & Cyprus...all par for the course.  How more predictable can life be?!!!

In the midst of all this extreme normality I've been reading through a lot of my papers on tendinopathies, given that I've been asked a lot of questions with regards the assessment & management of Achilles & patellar tendons in particular recently.  The thing with tendinopathies is that they are commonplace in so many sporting environments, a fact demonstrated by the diverse background of the athletes & their physios that have been in touch: endurance athletes, footballers, rugby players, lacrosse players, cyclists & more explosive track & field athletes to name but a few.

There's no doubt that the most cited authors in this field are the likes of Hakan Alfredson, Jill Cook, Karim Khan, Nicola Maffuli & my good friend, Henning Langberg.  If you only read papers that these 5 had been involved in, you would know one heck of a lot about tendinopathies.  

In terms of the subjective assessment, it's worth bearing in mind Leadbetter's Principle of Transitions (1992), which states that an injury is most likely when an athlete has made some kind of training change, whether this be training routine (intensity, frequency, duration), training surface, equipment or technique.  For those working in team sports, a cluster of presentations will most likely point you in the direction of training routine or surface & so it is worthwhile discussing the training with the coaching staff too.

Back in 2001, Robinson et al (which unsurprisingly includes Jill Cook & Nicola Maffuli in the list of co-authors), published a paper in the British Journal of Sports Medicine, supporting the validity & reliability of the VISA-A questionnaire, which is an index of clinical severity of achilles tendinopathy.  The questionnaire provides a useful outcome measure that can be used to monitor progress from a point of initial assessment.

This year Iversen et al (which unsurprisingly includes Henning Langberg as one of the co-authors), published their findings of a review of 26 clinical trials, including 1,336 subjects, concluding that it was indeed a reliable tool for providing a good assessment of the actual condition from very poor to excellent.

A similar VISA questionnaire was constructed by Visentini et al (which unsurprisingly includes Karim Khan & Jill Cook in the list of co-authors) to provide a tool for assessment of the clinical severity of symptoms in patients with "Jumper's Knee" & was published in the Journal of Sports Science & Medicine in 1998.

The information gleaned in the subjective assessment should also start guiding you towards a differential diagnosis of the tendinopathy, to ensure the initial presentation is appropriately managed & the rehabilitation programme correctly prescribed.  The following table worth considering.

Type of Tendinopathy


Tendon Dysrepair







Short Term Load

Ongoing Strain

Further Strain


Very Painful (If Extensive)


Often Grumbly

As far as the objective assessment is concerned, the mistake that many inexperienced clinicians will make is that they concentrate too locally to the area of symptoms.  A thorough objective assessment will consider (in no particular order):

- Joint mobility
- Skeletal alignment
- Muscle bulk
- Muscle length
- Tendon size
- Swelling nature
- Muscle length
- Functional biomechanics
- Neural distribution
- Pain characteristics on provocation

If I simply address the assessment of joint mobility in relation to the Achilles & patellar tendons, the joints of the foot, ankle, knee & hip must all be considered.  A great text for getting to grips with the physiology of the joints is Kapandji's "The Physiology of the Joints.  Volume Two: The Lower Limb" & much of the detail below is taken from this.  


The excursions during contraction of the three components of the triceps surae are quite different, with the efficiency of the gastocnemius depending closely on the degree of knee flexion/extension.  Between end range knee flexion & end range knee extension, the origins of the gastrocnemius produce a relative elongation or shortening, which is equal to or exceeds the excursion of the tendons.

In knee extension: the gastrocnemius is passively stretched, thus enabling it to generate maximal power, allowing force transfer from the quads to the ankle.

In knee flexion: the gastrocnemius is fully slackened, with the excursion bringing the origin closer to the insertion, thus losing its mechanical efficiency & the soleus becomes the only active muscle.  However, the soleus couldn’t generate enough power to allow walking or jumping if knee extension wasn’t a component part of these activities, thus enabling the tendon to store energy.

Combined ankle/knee movements: any movement combining ankle extension & knee extension activates the gastrocnemius, with the triceps surae achieving maximal efficiency when, starting from the ankle flexed, knee extended position it contracts to extend the ankle, thus providing the propulsive force during the last phase of the step.

However, if full range of movement is not available at one or other of the joints, mechanical efficiency is lost & the tendon will not be loaded maximally.  In addition, the effect on the ankle mechanics caused by mid-tarsal hypomobility or hallux rigidus/limitus ensures that these joints must also be included in the objective examination.



The patella moves in a sagittal plane on knee flexion/extension, as it recedes along the arc of a circle & also undergoes axial rotation with respect to the tibia.

During movements of axial rotation, the patellar moves in a coronal plane in relative to the tibia. 

In neutral tibial rotation: the patellar tendon runs slightly oblique inferiorly & laterally. 

In medial tibial rotation: the femur is laterally rotated in relation to the tibia, which pulls the patella laterally, so that the patellar tendon now runs obliquely inferiorly & medially.

In lateral tibial rotation: the femur is medially rotated in relation to the tibia, which pulls the patella medially , so that the patellar tendon now runs inferiorly & laterally with a greater obliquity than in neutral tibial rotation.

Therefore patellar displacements relative to the tibia are crucial for both knee flexion/extension & tibial rotation & if the patellofemoral joint becomes hypomobile the tendon will be adversely loaded.

Limitation in ankle dorsiflexion range has also been shown to increase the risk of patella tendinopathy (Backman & Danielson, 2011).  The exact mechanism of this has not been definitively described, however, the theories propose that either:

i)   the lack of ankle dorsiflexion is very influential on landing mechanics, which could alter the knee dynamics due to excessive tibial lateral rotation/femoral medial rotation & subsequent increases in inferolateral pull of the patellar tendon

ii)   the reduced capacity of the ankle joint to absorb kinetic energy on landing may increase demand on the patellar tendon to absorb kinetic energy on landing

Backman, L.J. & Danielson, P. (2011). Low range of ankle dorsiflexion predisposes for patellar tendinopathy in junior elite basketball players: a 1-year prospective study. Am J Sports Med, 39(12): p2626-2633

In addition, limited range of movement in the hip joint or dysfunction of the sacroiliac joint will also affect the rotational control of the femur.  Consequently the relationship with the tibia & patellar will be affected, as will the load imparted on the patellar tendon.

Over the next few blogs I will come back to look at different components of the objective assessment of the patellar & Achilles tendinopathies & would welcome any contributions left in the Comments box below.  In addition, another paper that was published earlier this year, which provides a recent overview of the available literature is that by Mark Reinking, which can be found in the Physical Therapy in Sport Journal.

Reinking, M. (2012).  Tendinopathy in athletes.  Phys Therapy Sport, 13: p3-10

So, in the midst of all this routine, normality & predictability in the worlds of sport & tendinopathy research, I leave you to peruse through the papers above.  Meanwhile, I'm off to research the runners & riders for the Grand National to ensure that my one flutter of the year is a somewhat informed decision!  Have a great weekend!!!

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