How do I know if my Achilles tendinopathy is insertional or midportion?

Location is the key indicator. Insertional tendinopathy causes pain right where the Achilles attaches to the heel bone -- you can usually pinpoint it by pressing on the back of the heel. Midportion tendinopathy causes pain 2 to 6 centimeters above the heel, often with a noticeable thickening or nodule in the tendon. Your provider can confirm the type with ultrasound imaging.

Will the Alfredson eccentric heel drop protocol help my insertional Achilles tendinopathy?

The Alfredson protocol -- performing heel drops off a step -- has strong evidence for midportion tendinopathy but can actually worsen insertional cases. The end-range dorsiflexion compresses the tendon against the heel bone at the insertion point. Modified protocols that limit range of motion or use isometric loading may be better options for insertional tendinopathy.

Is shockwave therapy FDA-cleared for Achilles tendinopathy?

ESWT for Achilles tendinopathy is considered an off-label use. While clinical research supports its effectiveness, particularly for midportion tendinopathy, it has not received specific FDA clearance for this indication. The FDA has cleared ESWT devices for plantar fasciitis and lateral epicondylitis.

Insertional vs. Midportion Achilles Tendinopathy

Two runners visit the same sports medicine clinic with Achilles pain. One feels it right at the back of the heel. The other feels it several centimeters higher, in the thick of the tendon. They have the same tendon, the same general complaint – but they don’t have the same condition, and they shouldn’t receive the same treatment.

The distinction between insertional and midportion Achilles tendinopathy (chronic tendon damage, sometimes called tendonitis) is one of the most clinically important differentiators in lower extremity care, yet many patients never learn which type they have. If you’re considering shockwave therapy for Achilles tendinopathy, understanding this distinction can mean the difference between a protocol that helps and one that falls short.

Anatomy of Two Different Problems

The Achilles tendon is the largest and strongest tendon in the body, connecting the calf muscles (gastrocnemius and soleus) to the heel bone (calcaneus). Despite its strength, it’s vulnerable to overuse injuries – and where on the tendon the damage occurs determines the subtype.

Midportion tendinopathy affects the tendon body 2 to 6 centimeters above the heel. This zone is called the “watershed area” because it has relatively poor blood supply compared to the rest of the tendon. That limited circulation makes it prone to degeneration when subjected to repetitive stress. You may notice a visible thickening or nodule in the tendon at the painful spot.

Insertional tendinopathy affects the point where the tendon attaches to the calcaneus – the enthesis. This region is subjected to compressive forces in addition to tensile loading, especially when the ankle bends upward (dorsiflexion). The insertion can also be complicated by Haglund’s deformity (a bony bump on the back of the heel) and calcification within the tendon at its attachment point.

The fundamental difference: midportion disease is primarily a problem of tensile overload and poor vascularity, while insertional disease involves compression, bony morphology, and sometimes calcification.

Why the Distinction Matters for Rehabilitation

This is where many treatment programs go wrong. The most widely studied rehabilitation protocol for Achilles tendinopathy is the Alfredson eccentric heel drop program, which involves performing slow, weighted heel drops off the edge of a step.

For midportion tendinopathy, this protocol has strong evidence. The eccentric loading stimulates tendon remodeling and has been shown to reduce pain and improve function in multiple randomized controlled trials (Alfredson et al., 1998, American Journal of Sports Medicine).

For insertional tendinopathy, the same protocol can make things worse. The deep ankle dorsiflexion at the bottom of the heel drop compresses the tendon against the heel bone at precisely the point that’s already damaged. This is why some patients do their prescribed exercises diligently and end up in more pain.

Modified approaches for insertional cases include:

Flat-ground eccentric exercises (no step, eliminating the compression at end-range)
Isometric loading at mid-range (pain relief without aggravation)
Activity modification to reduce compressive forces (avoiding uphill walking, minimizing deep squats)

Shockwave Therapy: Different Evidence, Different Protocols

The research on ESWT for Achilles tendinopathy is split along the same insertional-versus-midportion line.

Midportion tendinopathy has the stronger evidence base. A systematic review by Mani-Babu et al. (2015, British Journal of Sports Medicine) found that ESWT showed positive outcomes for chronic midportion Achilles tendinopathy, particularly in patients who had not responded to eccentric loading programs. The treatment stimulates neovascularization (new blood vessel formation) in the hypovascular watershed zone – addressing one of the key biological drivers of the condition.

Insertional tendinopathy research is emerging but less definitive. The complicating factors – calcification, Haglund’s deformity, and compressive forces – make the clinical picture more complex. Some studies suggest ESWT can help reduce calcification within the tendon insertion, and patient-reported outcomes in observational studies have been encouraging. However, the randomized controlled trial evidence is thinner compared to midportion disease.

Protocol Adjustments by Subtype

Providers experienced in treating both subtypes typically adjust the ESWT protocol:

Parameter	Midportion	Insertional
Device type	Radial or focused	Focused often preferred
Energy level	Standard	May use higher energy for calcific deposits
Patient positioning	Prone, ankle neutral or slightly plantarflexed	Prone, ankle in slight plantarflexion to expose insertion
Target area	Thickened tendon body	Tendon-bone junction, any visible calcification
Sessions	3-5	3-6 (may need more if calcification present)

The key difference: insertional protocols may specifically target calcific deposits within the tendon attachment, using higher energy settings to promote resorption of the calcium. This is where the treatment begins to overlap with the principles used in calcific shoulder tendinitis.

The Role of Haglund’s Deformity

If you have insertional Achilles tendinopathy, your provider should evaluate for Haglund’s deformity – a bony prominence on the back of the heel bone that can impinge against the tendon, creating a mechanical irritant that perpetuates the problem.

When Haglund’s deformity is significant, ESWT alone may not fully resolve the issue because the bony bump continues to compress the tendon with every step. In these cases, shockwave therapy might be combined with footwear modifications (avoiding rigid heel counters) or, in refractory cases, surgical excision of the prominence.

Combining ESWT with the Right Rehabilitation

Shockwave therapy works best as part of a comprehensive rehabilitation plan – not as a standalone treatment. The rehabilitation approach should match the subtype:

For midportion tendinopathy:

ESWT sessions + progressive eccentric loading (Alfredson protocol)
Gradual increase in tendon loading over 12 weeks
Understanding what to expect from ESWT vs. other modalities helps set realistic timelines

For insertional tendinopathy:

ESWT sessions + modified loading (flat-ground eccentrics or isometrics)
Shoe modifications to reduce posterior heel pressure
Addressing biomechanical factors (calf tightness, overpronation)

Providers with strong sports medicine backgrounds can offer expertise in both subtypes.

The Bottom Line

Insertional and midportion Achilles tendinopathy are distinct conditions that require different rehabilitation strategies and different shockwave therapy protocols. Midportion disease has stronger evidence supporting ESWT, while insertional cases may need modified approaches that account for calcification and compressive forces. Knowing which type you have is the essential first step toward effective treatment – ask your provider for a specific diagnosis before beginning any treatment program.

Read our guide to Achilles tendinopathy to learn more about how ESWT is applied to different subtypes.

References

Alfredson H, Pietilä T, Jonsson P, Lorentzon R. Heavy-load eccentric calf muscle training for the treatment of chronic Achilles tendinosis. Am J Sports Med. 1998;26(3):360-366. PubMed
Mani-Babu S, Morrissey D, Waugh C, Screen H, Barton C. The effectiveness of extracorporeal shock wave therapy in lower limb tendinopathy: a systematic review. Am J Sports Med. 2015;43(3):752-761. PubMed