Achilles and eccentric loading

Achilles Tendinopathy: Are heel drops for me?

A common question in the clinical environment is “when should I start heel drops (eccentric loading) for my Achilles?”

Before we answer that question we should consider if they are appropriate as a part of a rehabilitation program. Not all cases of Achilles Tendinopathy will respond in a positive manner.

Let’s take a brief look at your options at different stages of pathology:

Acute stage – in the case of an acute bout of Achilles pain in the distance runner we still do not really know if/how much the inflammatory response is involved in this type of scenario. Despite showing signs and symptoms it is not conclusive. The fact that tendinopathies tend to operate on a continuum may suggest multiple occurrences.

In any case a period of tendon de-loading is recommended. This allows the tendon to go through the initial healing process. There are two presentations here in the acute onset;

1.     An acute overload leading to a (possible) inflammatory exudate within the paratendon (tendon outer layer/covering)

2.     An acute onset with a degenerative pathology being the underlying condition. In this case the pathogenesis has probably been going on behind the scenes without any symptoms. The onset will be acute, the pathogenesis not so.

Chronic stage(s)

1.     Chronic Achilles Tendinopathy is common in cyclic sports such as running and as such presents with a long history of nagging pain progressively getting worse as the runner continues to load the tendon. As stated tendon pathologies occur on a continuum with a progressive overlapping of stages., chronic may be considered to be the end stage

How do we know the difference?

This can be difficult however, usually acute signs will be due to high loads over the short term (days/weeks) and will be exquisitely tender to run and/or palpate.  It may also be red, hot and swollen and may present with crepitus. This can sometimes be heard as the tendon glides within the paratendon, almost like a ‘creaking’ sound.

An acute onset with an underlying degenerative process does not (usually) present with this scenario. Typical signs here are a thickened Achilles tendon, stiffness and pain on awakening only to warm up. There may be thickened nodules palpable typically through the mid-portion. Often there is accompanying lack of range in dorsiflexion.

Further investigation such as MR imaging or ultrasound may show further degenerative changes and is our most reliable form of assessment.

Chronic Achilles Tendinopathy as the name suggests has presented itself months before and despite a low level of nagging pain and stiffness the runner continues to log the miles. Chronic cases almost always show multiple changes at the cellular level (these have been discussed in a previous post – “The old Achilles”)

What else needs to be considered?

The second factor, which is huge in Achilles pathology, is location. Achilles pain presenting in the mid-substance (2-6cm above insertion) generally has a better prognosis than pain at the insertion (less than 1 cm above insertion). The reasons are not clear, further research is needed to fully understand the complex nature of insertional tendinopathies.

Heel drops may be appropriate for chronic Achilles patients where the mid portion is involved. Insertional tendinopathies generally show poor outcomes with heel drops as the aetiology is thought to be different (compression is believed to be a large factor involved with insertional tendinopathies). Dropping the heel below parallel as with eccentric loading places increased compression on the tendon. Insertions generally do not like to be stretched. Taking the load off the tendon with heel inserts often proves beneficial.

Clinical experience will show those that embark on heel drops with insertional pathologies will generally have a poor outcome. A better place to start may be heel drops from the floor – this reduces the compressive factor but still applies a progressive load.

Acute tendinopathies do not tend to respond in the same way clinically. Loading tissues showing hallmarks of inflammation (acute only) tends to further irritate the tissues. A period of de-loading for 1-2 weeks is recommended before a decision on heel drops is made. Subjective and objective history will be your guide here.

How Long can I expect to see results?

There is no consensus on a ‘standard’ for loading parameters however the original research provided by Alfredson (1998) is often used as a starting point. He used 3 sets of 15 reps straight leg and bent leg heel drops performing only the eccentric portion on the affected leg over a 4 second descent. These were performed twice daily, through moderate pain with the weight progressively increasing. A total of 180 reps is performed daily over a 12-week period. Improvements need to be monitored weekly and progression made accordingly

Summary

Heel drops are indicated in most chronic mid portion Achilles tendinopathies. Acute and insertional tendinopathies require modification and management. As tendon research improves so will our understanding of clinical treatment. This is one aspect of conservative therapy and thus needs to be determined if it is appropriate.

For further information on tendon research Professor Jill Cook, Dr Jamie Gaida and Craig Purdam (AIS) from Australia are at the forefront. Overseas pioneers in this field include Hakan Alfredson and Lars Ohberg. An abundance of information can be found in journals and on the internet for the like minded reader.