The debate rages on. What is the most effective contraction type for Achilles tendinopathy? The evidence has shifted between concentric and eccentric loading over the past couple of decades. Should one be favored over the other? Is it irrelevant provided the load is high? Are both needed for the best outcomes? This systematic review and meta-analysis (PMID: 36698184)investigated the efficacy of eccentric exercise for mid-portion Achilles tendinopathy.
The review consisted of trials comparing eccentric exercise with another form of conservative treatment. The primary outcome was pain or function. I would prefer to see strength, muscle size, and tendon stiffness but they were not included in this review. Ruptured tendons and insertional tendinopathies were excluded as well. The final review included 8 studies (401 tendons and 371 patients ranging from 19-77 years old). The MA found pain improvements were significantly greater in the eccentric groups, but the clinical significance is questionable with a mean improvement of 1.21 (2.72 to − 0.30, 95% CI). Given the small number of studies and restriction of assessing pain only (with wide confidence intervals that cross 0), I don’t think this review supports the message that eccentric loading is the preferred contraction type for mid-portion Achilles tendinopathy. It’s perfectly useful, just not better than concentric or a combination.