It is no accident that the Achilles tendon is so named. The term for the thick sinewy tendon running down from calf to foot is a permanent reminder of its vulnerability. The Achilles heel, for those whose Greek mythology needs a little recap, derives from the legend in which Achilles’ mother, the sea nymph Thetis, dipped her baby son into the River Styx to render him invulnerable, protecting him against his many foes. He became a great hero, but was finally felled by an arrow through his heel – the spot where his mother had held him while she dipped him in the river and therefore his sole spot of vulnerability. Thus we have “Achilles’ heel” to indicate someone’s weak spot…
It is, and for all athletes should be, a constant reminder to treat the Achilles with great respect. If you don’t you could gain an injury for life.
Achilles tendinopathy is a common injury in running, jumping, tennis and other racquet sports, and in team sports such as football. It has a lifetime cumulative incidence of 50% among elite endurance athletes.
Which all adds up to a lot of Achilles injury.
All the more surprising then, that it has taken a long time for sports medicine to get to grips with the true nature of tendinopathies. We have come a long way from the days when we talked in terms of swollen tendons (tendinitis) being treated with a hot pack and stretching. Yet, even though we know much more about what is going on, neither the science nor the prescriptions are as yet definitive. So the sports therapist needs to remain on top of this subject.
“While eccentric loading has a good record of ‘success’, you and your clients need to be clear: this is not a one-off rehab fix, but an exercise regime that needs to be continued for ever”
There are two good reasons why an Achilles tendinopathy is no short-term injury:
* it is adaptive changes within the tendon — new collagen growth and blood vessel invasion – that cause the pain, so by the time the athlete is aware of the problem, most of the damage has already been done;
* the damaged tissue will be functionally weaker and will remain permanently “Type 3” collagen; thus it is more susceptible to reinjury than the original Type 1 collagen fibres it replaces.
Ice v heat
Many of us reach for a hot pack as an intuitive remedy for soft-tissue pain. This is quite useful in muscle strain injuries to the lower back, acute neck problems and grumbling joint injuries. But in degenerative tendon pathology, applying heat to an area of new blood vessel growth may promote an extraordinary blood flow response in those small invading blood vessels, which may then exacerbate pain. By contrast, the application of ice to the offending area may reduce the blood flow to the microscopic vessels that are causing the pain.
Why exercise works
Eccentric exercise improves tendon pathologies by stimulating tenocytes (collagen-producing cells) within the tendon. The tenocytes respond to eccentric stress by laying down more Type 1 collagen into the healthy and non-affected tendon tissue. So the tendon tissue surrounding the degenerative ‘hot spot’ is strengthened. This is not a repair of the hot spot itself, but serves to offload pressure on it. The tenocytes seem to respond to both low-speed and high-speed eccentric loading; what matters is not the speed but the type of loading. It has even been demonstrated that concentric exercise has nowhere near the same benefits as eccentric exercise.
While eccentric loading has a good record of ‘success’, you and your clients need to be clear: this is not a one-off rehab fix, but an exercise regime that needs to be continued for ever. Evidence seems to suggest that it is the constant tensile load in eccentric exercise that stimulates the tenocyte activity and continues the whole remodelling process within the tendon. If the load is ceased, over the course of time the collagen becomes thinner and weaker.
It is common for athletes to cease their eccentric training in the off-season, believing their problem to be sorted, as they are feeling fine. But once they restart their pre-season running, the tendon pain returns with a vengeance.
The Alfredson 180 calf raise
The specific eccentric training regime often recommended for Achilles pathologies is the Alfredson ‘180 repetition’ calf-raise programme. This involves doing 3 x 15 eccentric heel drops with the knee straight, and 3 x 15 repetitions with the knee bent, repeated twice daily. It ideally involves only the eccentric component. The athlete lowers their body down on the affected leg, then places the foot of the non-affected leg on a step to raise the body back up to the starting point.
If this proves too difficult, or if both Achilles are affected, it is possible to raise back up on both legs (thereby sharing the concentric load) and coming down on a single leg (this is the ‘2 up, 1 down’ concept).
Stay strong, train hard and live longer.