ACHILLES TENDINOPATHY REHABILITATION & RTS

Mid-portion and insertional Achilles tendinopathy are not the same

A key starting point in Achilles rehabilitation is identifying where the tendon is symptomatic.

Mid-portion Achilles tendinopathy affects the middle third of the tendon, where tensile load is the main mechanical driver. Insertional Achilles tendinopathy affects the calcaneal insertion, where compression against the heel bone becomes an important aggravating factor in addition to tension.

This distinction changes exercise selection.

For mid-portion tendinopathy, loading through a larger ankle range, including dorsiflexion, can be appropriate as capacity improves.

For insertional tendinopathy, excessive dorsiflexion can increase compression at the tendon insertion. Early and mid-stage exercises are therefore generally performed without allowing the heel to drop below neutral.

The same calf exercise can therefore be useful for one presentation and unnecessarily provocative for the other.

Rehabilitation should progress through three loading phases

Achilles rehabilitation can be organised into three broad stages:

Isometric → isotonic → plyometric

Each phase prepares the tendon for a different demand.

Isometrics are primarily used early to introduce load and manage symptoms. Isotonic resistance develops strength and tendon load tolerance. Plyometric training restores the tendon’s ability to store and release energy during running, jumping and sport.

Progression should not be dictated simply by the number of weeks a patient has been in rehabilitation. The tendon should demonstrate enough tolerance and capacity to handle the next level of loading.

Phase 1: Isometric loading

Early rehabilitation does not necessarily require complete rest.

Isometric calf loading can provide a way to expose the tendon to meaningful tension without the larger movement demands of dynamic exercise. Some patients also experience short-term pain reduction after isometric exercise, although this response is not universal.

A common approach is to use moderate-to-high effort holds while keeping symptoms controlled.

For mid-portion Achilles tendinopathy, standing calf-raise holds can be used in a neutral ankle position.

For insertional presentations, seated isometric loading is often preferable because it allows the soleus and Achilles complex to be trained while limiting dorsiflexion and compression at the insertion.

The aim at this stage is not simply to make pain disappear. It is to begin restoring the tendon’s tolerance to load.

Phase 2: Build strength with progressive resistance

Once dynamic loading is better tolerated, rehabilitation progresses toward slow, progressively loaded calf strengthening.

Both the gastrocnemius and soleus need attention.

Standing calf raises place greater emphasis on the gastrocnemius, while seated calf raises provide a stronger soleus bias. This matters because the soleus contributes substantially to force production during running and should not be treated as a secondary muscle.

Slow resistance work can use controlled concentric and eccentric phases, for example approximately three seconds up and four seconds down.

A typical strength phase may use:

• 3–4 sets

• 6–12 repetitions

• around 3 sessions per week

• progressive resistance

• meaningful effort rather than very easy repetitions

For insertional Achilles tendinopathy, calf raises should initially remain on a flat surface. Heel-drop exercises that move the ankle into deeper dorsiflexion are avoided because they increase compression at the insertion.

For mid-portion tendinopathy, larger ranges of motion can progressively be introduced.

Train both legs, not only the painful side

An often overlooked strategy is cross-education.

Heavy strength training of the unaffected leg can produce neural adaptations that partially transfer to the injured side. This can help limit strength loss during periods when the symptomatic tendon cannot yet tolerate full loading.

Training both legs also reduces the risk of returning to sport with large strength asymmetries.

The unaffected side therefore has an active role in rehabilitation rather than simply serving as a comparison limb.

Phase 3: Restore energy storage

A strong tendon is not automatically a sport-ready tendon.

Running and jumping expose the Achilles to rapid loading, short ground-contact times and repeated storage and release of elastic energy. Rehabilitation therefore needs to progress beyond slow resistance training.

Plyometric work can begin with relatively simple drills such as bilateral pogos before progressing toward:

• unilateral pogos

• lateral and cross-pattern jumps

• repeated hops

• bounding and skipping

• hurdle work

• box jumps

• drop jumps

Volume should initially be low and then increased according to tendon response.

These sessions also require recovery. Energy-storage loading is more demanding than slow strength work, so spacing plyometric sessions across the week allows the tendon to adapt without repeatedly exceeding its current tolerance.

Do not rehabilitate only the Achilles

The symptomatic structure may be the tendon, but the contributing problem does not always sit at the ankle.

Altered hip mechanics have been identified in runners with Achilles tendinopathy, which supports assessing the entire kinetic chain rather than focusing exclusively on calf raises.

Depending on the individual, rehabilitation may also include:

• hip abductor strengthening

• single-leg press work

• trunk control

• single-leg stability

• running mechanics

• ankle mobility

Reduced ankle dorsiflexion can also influence Achilles loading, so talocrural mobility remains relevant where restriction is present.

The goal is to restore the system that produces and absorbs force, not simply strengthen one tendon in isolation.

Measure progress instead of relying on symptoms alone

Pain improvement is important, but symptom resolution alone does not confirm that the athlete has restored the capacity required for running or sport.

Useful outcome measures include the VISA-A, which tracks Achilles-related pain, function and activity, alongside pain ratings and patient-specific functional goals.

Strength and functional symmetry can also be assessed using the Limb Symmetry Index:

LSI = injured-leg performance ÷ uninjured-leg performance × 100

Around 90% symmetry is commonly used as a practical return-to-sport benchmark, although it should not be treated as a universal stand-alone cut-off.

Testing may include:

• single-leg calf-raise performance

• plantarflexion strength

• single-leg hop tests

• repeated hop tests

• drop-jump symmetry

• sport-specific functional tasks

Return to running and sport should therefore be criteria-based rather than purely time-based.

The key principle is progressive loading

Achilles tendinopathy rehabilitation should not be reduced to one exercise or one loading method.

The progression is more important:

manage symptoms → restore strength → restore energy storage → restore sport-specific capacity.

Mid-portion and insertional presentations require different loading modifications, both the gastrocnemius and soleus need sufficient attention, and the kinetic chain should be assessed rather than treating the tendon in isolation.

Adjuncts such as blood-flow restriction, nutrition strategies or sensory retraining may have a role in selected patients, but they should support rather than replace the central intervention: appropriately dosed, progressive mechanical loading.