Achilles tendon rupture is not a pleasant experience. Research suggests that the Achilles is one of the most frequently ruptured tendons, mainly occurring in middleaged men during sporting activities (that’s not an excuse to sit on the sofa with a brew and a chocolate biscuit). And the incidence of ruptures is on the increase.
There are two main schools of thought when it comes to rehabilitation: surgical repair or nonsurgical rehab. In addition, it has become common after surgery to include early functional mobilisation, such as using an adjustable brace, and now the same approach is being taken with promising results in non-surgical settings.
But how do we know which approach is the most effective? Patient-reported outcome scores are an increasingly popular way to help therapists evaluate functional results and to compare incapacity on an individual level. Several valid and reliable scores are in general use for shoulder, knee and ankle injuries, and there are also specific scoring systems for evaluating patients with patellar tendinosis and Achilles tendinopathy. But what if your tendon has gone snap and you are recovering from a rupture? Researchers based in Sweden have the solution(‘The Achilles tendon total rupture score (ATRS):development and validation’, The American Journal of Sports Medicine2007: 35 (3) 421-426), an easily self-administered, validated and sensitive scoring system with high reliability, which evaluates symptoms and their effect on physical activity in patients with Achilles tendon rupture. For the first time, clinicians have a tool that will allow them to compare and contrast different rehabilitation modalities.
The new patient-reported outcome measure (ATRS) can be completed in a couple of minutes, and the score from the 10 items is determined in less than a minute, providing a useful tool for rehabilitation staff to see just how well their rehab programme is going.
Taking the strain
Tendons are specialised structures that transfer forces between muscles and bones. The frequency, duration, and/or magnitude of tendon forces can change dramatically in response to changes in physical activity and muscle strength, but little is known about the interactions between muscle and tendon adaptations in living people. Researchers from California have just completed a study to see if the Achilles tendon adapts to changes in muscle strength to maintain strains within a preferred operating range (‘Achilles tendon adaptation during strength training in young adults’, Medicine and Science in Sports and Exercise2007: 4039 (7) 1147-1152).
Subjects taking part in the study performed an eight-week strength-training programme (3 x 10 heel raises at 70% of maximum force) consisting of three weekly sessions separated by at least one day of rest. They were tested before and at the end of the first, second, fourth, sixth and eighth weeks to see if increased strength had an effect on the peak strain in the Achilles tendon.
This is the first study to have quantified Achilles tendon strain throughout a strength training programme; what it showed was that the Achilles seems to have a preferred strain limit that is maintained even as muscle strength increases. The actual level of strain seems to vary greatly between individuals.
Does eccentric loading work? It’s not just top athletes who get problems with their Achilles tendons. A sore Achilles can also stop us mere mortals in our tracks. If you trawl through the research you will find numerous studies expounding the virtues of different strategies for the rehabilitation of Achilles tendinopathy, including, controversially, the use of eccentric calf muscle training.
The use of eccentric loading to rehabilitate tendon injuries first came to light in the mid 1980s, but it wasn’t until the late 1990s that the rehab community fully embraced the concept. While there is a lot of support for this intervention with an athletic population, there is very little evidence to suggest that it is an effective treatment within a ‘non-athletic’ population (by which we mean you, probably most of your clients, and me!).
Researchers from Keele University School of Medicine in the UK undertook a study to fill the knowledge gap (‘Eccentric calf muscle training in non-athletic patients with Achilles tendinopathy’, Journal of Science and Medicine in Sport 2007: 10 52-58). To qualify as sedentary, the patients taking part in the study had to have had a physical activity exercise habit over a six-month period of less than three 20-min exercise sessions a week.
The patients (who all had Achilles tendinopathy) underwent a graded progressive eccentric calf strengthening exercise programme (heel drops) for 12 weeks. They were advised to continue the exercises through mild or moderate pain, stopping only if the pain became unbearable.
At the start of the study the patients completed the VISA-A questionnaire – 10 questions developed by the Victorian Institute of Sport in Australia to assess pain and activity. They continued to complete the questionnaire at subsequent visits.
Forty-four per cent of the patients did not improve with eccentric exercise, and the researchers concluded that, while the programme was effective in almost 60% of subjects, it might not benefit sedentary patients to the same extent as has been reported in athletes. That said, I’ve worked with plenty of athletes with niggly Achilles tendons, and I’ve found that although eccentric loading worked wonders with some, it didn’t make any difference for others…
Personally I’m not sure it has much to do with activity levels. The key is not to take a one-size-fits-all approach. Eccentric loading is going to work for some people, and not for others.