Happy new year – hope all the readers have a wonderful 2016.
This year I will do a weekly tendinopathy research update to make sure you are always up to date – you can subscribe from the homepage.
The first LOWER LIMB TENDON COURSE is scheduled for 2016 – in Melbourne Feb 20/21 – details here.
Now for some exciting tendon research from the end of 2015 – contoured sandals for plantar fascia, evidence for central pain processing changes in tendinopathy, and an opinion piece central tendon injuries, and some other bits.
Hope you enjoy
We start from this hot off the press study from Tompra in BJSM on a current hot topic in tendons. They investigate central pain processing in Achilles tendinopathy. There are arguments that tendon pain is nociceptively driven because it remains localised and does not display other central pain features such as lingering pain, and it maintains a strong stimulus response relationship. This is true for the most part, but as a clinician who sees lots of tendon patients, I do see a fair proportion of patients who have central pain features on a background of lower limb tendinopathy. In this study Central Pain Modulation (CPM) was used to investigate the efficacy of descending pain modulatory pathways. A noxious conditioning stimulus is applied which should result in pain inhibition after. Persistent pain represents a dysfunction in inhibitory circuits. They compared runners with Achilles tendinopathy and controls and found less CPM pain inhibitory effect in the Achilles group (suggesting central pain processing changes among this cohort of Achilles patients). The authors argue that this may be due to sustained peripheral nociceptive activity that may sensitise nociceptive neurons and reduce the COM effect. Although these findings may be explained by local nociceptive drive, it nevertheless strengthens the argument for a strong central component in chronic tendon pain states – accepted in the upper limb, but not so much in the lower limb, yet.
Second paper is by Prof Bill Vicenzino and coworkers. They have performed an RCT comparing prefab orthotics, contoured sandals and flat flip flops (thongs, jandals, etc). Outcome assessment was performed by a researcher blind to the group allocation and follow up was performed to 12 weeks. The proportion of patients reporting benefit on the global rating of change at 12 weeks was significantly greater in the orthotic (59%) and contoured sandal groups (61%) compared to the flat flip flop group (34%). On the Lower Extremity Functional Scale the contoured sandal group were 61% more likely to report a clinically meaningful improvement compared to the flat flip flop group at 12 weeks. The authors conclude based on number needed to treat stats: “For every 4 patients with plantar heel pain wearing a contoured sandal, one more would be expected to be quite a bit better, a great deal better or a very great deal better than if they wore a flat flip-flop.” A clear message and timely paper, particularly here in Australia, given we are in the middle of a record hot summer.
Prof Steve Tumilty and colleagues have performed an interesting RCT. Essentially it is an RCT comparing two exercise programs in Achilles tendinopathy – the first a classic eccentric program including the typical knee bent and straight raises twice per day and 7 days per week. The second a modified Alfredson eccentric program with much reduced volume – i.e. performed 1x/day and only twice in the week. They also investigated whether adding laser to each of the exercise protocols would improve outcomes – they had 4 arms in total, i.e. each exercise group with a laser placebo or actual laser comparison group. Outcomes were assessed by blinded assessors at baseline, 4 and 12 weeks. VISA improvement was statistically and clinically significant in all groups – the only group difference was greater improvement in the group that received laser + the watered down version of the Alfredson program. Tendon thickness reduced with no significant between group differences. The main take home is that exercise was beneficial in all groups, even a watered down/lower volume version. In my opinion, many people have moved away from the classic Alfredson program because it is time intensive and I agree with the authors when they say “the Alfredson protocol is not necessary to attain meaningful changes in pain and function”. As for the benefit from laser in the low volume exercise group not sure what to make of this – it adds to a conflicting literature (supporters of laser suggest dosage is not appropriate in the studies showing no effect). The pretty amazing improvement in VISA over the 12 weeks in all groups (25-30 points) suggests they reduced their activity/offloaded? Not clear in the study but they were allowed to run if minimally painful.
An interesting read from Gual et al. on the potential benefits of intense eccentric loading as a preventative strategy for patellar tendinopathy. 38 female and 43 male basketball and volleyball players were randomly assigned to a control and intervention group. Both groups performed regular training over 24 weeks and the intervention group also performed one weekly session of 4x8 inertial squat training with a flywheel device. Unfortunately, (for science and fortunately for them) no player in either group developed patellar tendinopathy, so the study does not tell us anything about prevention. As you would expect, countermovement jump performance and ecc and conc squat power improved in those performing the squats. So what this study tells us is that it seems safe in this cohort to perform heavy eccentric overload training in this way once per week – this contradicts Fredberg who showed that eccentrics among their soccer players increased the risk of pain, but only in the subgroup with ultrasound pathology at baseline. The difference may be Fredberg got them to do a low intensity/high volume stretch/eccentric training program 3x/week – possibly the increased exercise frequency and fatigue was an issue? Also we don’t know the ultrasound status of athletes in the study by Gaul. Is this a reason to buy yourself a flywheel ?? – maybe not yet (although it would be a fun toy).
A radiology study next up. The significance of imaging findings in tendinopathy have been debated for ages. Long et al. performed a retrospective review of patients imaged at their facility over 6 year for greater trochanteric pain syndrome. There were 877 patients and the main finding was that a huge number (700, 79.8%) did not have trochanteric bursitis. 438 (49.9%) had gluteal tendinosis, four (0.5%) had gluteal tendon tears, and 250 (28.5%) had a thickened iliotibial band. Obvious limitation is the diagnosis was not controlled as it was taken from the imaging referral. Regardless, it shows the bursa is not involved often, but I think we have moved on from trochanteric bursitis, yes?
Interesting narrative review by Prof Peter Brukner and A/Prof David Connell on intramuscular tendon involvement (see image below) in hamstring and quads muscle-tendon strains. They pick up on studies in the hamstring and quadriceps indicating that if the intramuscular tendon is disrupted return to sport time may be higher, and re injury rate may be higher. The authors argue that high quality MRI is useful (in contrast to another recent view in BJSM here) to delineate these injuries as it may inform prognosis but also rehab may vary. My view is rehab may well need to be different, ie consider more closely tendon load principles alongside usual consideration eg contraction type, load, speed development, kinetic chain, etc. The only issue is that the evidence linking these injuries to delayed recovery times is very limited at this stage.
Chimenti et al. investigated Achilles tendon insertion compression in 10 healthy participants and the effect that a heel lift had on compression. They used multiple ultrasound imaging frames during dynamic movement – ie the squat, to determine Achilles insertion compression in the deep and superficial part of the tendon. As expected, they found increased compression in the deep tendon and more so when performing a squat without a heel lift. Confirms the thinking that the therapeutic effect of a heel wedge may be related to reduced compression. This holds true for insertional Achilles tendinopathy, but what about midportion? Remember in the last research review we looked at the study by Weinert-Aplin et al. that found not reduction in Achilles strain/force in walking with a heel wedge, but a redistribution of load that still may be clinically relevant.
Clinical gems and awesome management models. Your patients will love you for it!