Tendonitis or tendinopathy??... That is the question, & maybe it should be one that we ask with a few other conditions as well!

This particular patient which I write about today had had pain in his right Achilles for about 9 months which hadn’t resolved with Physio, rest, ice...etc. It wasn’t terrible, & it didn’t really stop him doing anything, but it was a “niggle” & it did get worse when he ran.

In fact, if he hadn’t been a recreational runner, he admits he probably wouldn’t have bothered coming to see me! Its initial onset coincided with a change of lifestyle – he’d moved out of London into the countryside & was generally becoming a bit more active. The assessment was fairly straightforward, nothing really to report other than a functional hallux limitus & an ankle equinus – I use the lunge test for this because I think the fact that the patient is weight-bearing is more reflective of what’s going on rather than me forcing their foot into as much dorsiflexion as I can bear! I couldn’t honestly say there was much sign of inflammation so on that note I settled with Achilles Tendinopathy as a diagnosis.

Now it’s probably fairly safe to say that this patient’s symptoms are a combination of congenital & acquired factors, so before we go on, let’s just have a little look at what the papers say....

Azevedo et al (2009) suggested that altered knee kinematics and reduced muscle activity are associated with Achilles tendinopathy in runners, when they studied 42 subjects. This paper goes on to suggest that any mechanism, intrinsic or extrinsic, which affects the kinematics or muscle activity, may play a causative factor in the occurrence of Achilles tendinopathy. So with my patient ....  functional hallux limitus & ankle equinus are the intrinsic factors (congenital), & changes in his activity levels are the extrinsic factors (acquired). Again, looking more specifically at runners, Ryan, et al (2009) found an increase in “eversion displacement of the subtalar joint” in patients with Achilles tendinopathy compared to non-symptomatic subjects. This study also found that subjects with tendinopathy showed lower peak dorsiflexion velocity & the reduced arch height caused an inconsistent strain on the fibres of the Achilles tendon.

When I watched my patient walk it was quite clear there was some of that “eversion displacement of the subtalar joint” going on but this was probably compensating for the fact that his calves were too tight. Very simply put, the big toe wasn’t bending enough & neither was the ankle joint, so if we look at this in pure & simple sagittal plane mechanics ..... if the leg can’t go over the foot, it kind of goes around it. This causes a bit of a torque on the Achilles hence the discomfort. So essentially it wasn’t the pronation causing the problem it was the lack of range of motion at the 1st MPTJ & the ankle.... if I had just stuck a medial wedge under his heel I would probably have caused a multitude of other aches & pains! So instead, I issued him with a pair of simple insoles with a small heel raise, a distal hallux wedge (sometimes referred to as a “Cluffy” wedge) & a 1st ray cut out. Nothing particularly clever or fancy, but that sorted him out so I guess the moral of this little biomechanics story is to really look closely at what’s actually causing your patients symptoms.

As for the question at the beginning ...  Tendonitis or tendinopathy??... I think we should look at this in a bit more depth with a lot of the patients that we see. How many times do we diagnose plantar fasciitis without any clue as to whether there’s an inflammation or not? In 2003, Leinont et al. suggested that some presentations of plantar fasciitis manifest non-inflammatory, degenerative processes and should more aptly be termed "plantar fasciosis."..... But that’s another blog.



  • Azevedo, L., et al. (2009) “Biomechanical variables associated with Achilles tendinopathy in runners”, British Journal of Sports Medicine, (43) pp288-292
  • Leinont H, Ammiiati KM, Uscn N. (2003) Plantar fasciitis: a degenerative process (fasciosis) without inflammation../ Am PixHcur Med A.'93. pp234-237
  • Ryan, M., et al. (2009), “Kinematic Analysis of Runners with Achilles Mid-Portion Tendinopathy”. Foot & Ankle International. 30 (12) pp 1190-1195