The effect of an isometric plus eccentric-concentric exercise protocol compared to the usual care eccentric exercise protocol on Achilles tendon pain and structure in subjects diagnosed with Insertional Achilles tendinopathy - A pilot study

The Achilles tendinopathy (AT) is a clinical syndrome characterized by a
combination of pain and swelling in and around the Achilles tendon, accompanied
by impaired performance. This overuse tendon injury is common among
sport-active population, especially runners, but can also affect patients who
do not participate in sports. The incidence of AT in running athletes has been
estimated between 11% and 29%. On the non-sport population, Kujala UM et al
describe the incidence of 6%.
The Achilles tendinopathy can be classified as insertional, symptoms that occur
at the bone-tendon junction or as non-insertional, those that occur more
proximally. In the present study, the IAT will be the focus.
Eccentric exercises programme has been show to be successful for patients with
noninsertional AT, improving the VISA-A score and pain. But the results for IAT
are still unclear. There is no isometric exercise combined with
eccentric-concentric exercise described in the literature specifically for AT.
But a preview research with lateral elbow tendinopathy, which normally occurs
on the proximal portion of the tendon (similar to the IAT), observed a decrease
in pain score and an improvement of function.

The primary objective of this pilot study is to determine the effect of an
isometric exercises plus eccentric-concentric exercise protocol compared to the
usual care eccentric exercise protocol on Achilles tendon pain and structure in
subjects diagnosed with insertional Achilles Tendinopathy.

Randomized controlled trial (pilot study)

A computer-generated randomisation will lead into two groups of patients:

1. Isometric exercise plus eccentric-concentric exercise.
2. Eccentric exercise.

There are four measurement points: 0, 4, 8 and 12 weeks.

Group 1:
- Isometric exercise + eccentric-concentric exercise
To perform the isometric exercise program, patient will be instructed to
standing with all body weight on the forefoot and the ankle joint in plantar
flexion during 45 seconds. Patients will perform 5 repetitions each time and
the load will be increased as the same of eccentric group. After the four
weeks, all patients will be instructed to perform the eccentric-concentric
exercise until the twelfth week. The eccentric-concentric exercise is similar
to the eccentric exercise performed by the eccentric group, but pacients will
perform the concentric phase with the injured leg.


Group 2:
- Eccentric exercise
The protocol will be performed 2 times daily, 7 days/week, during 12 weeks.
Patient will begin the exercise from an upright body position and standing with
all body weight on the forefoot and the ankle joint in plantar flexion, the
calf muscle will be loaded by having the patient lower the heel until the floor
level.

Risks: No long-term risk known
Burden: Participation in the study will require two extra visits to UMCG for
the UTC and SWE scans and completion of questionnaires and the VAS pain scale.