This is a new study from my PhD student, Igor Sancho. He looks at strength, psychological and other factors that may be different between health runners and runners with Achilles tendinopathy. Seated calf raise 6RM seems to be the strongest predictor of having Achilles tendinopathy. Some interesting other findings and clinical implications. 

Here is a link to this paper, and Igor's other PhD papers:

• Sancho, I., Morrissey, D., Willy, R.W., Tayfur, A., Lascurain-Aguirrebeña, I., Barton, C. and Malliaras, P., 2022. Recreational runners with Achilles tendinopathy have clinically detectable impairments: A case-control study. Physical Therapy in Sport, 55, pp.241-247.
• Sancho, I., Malliaras, P., Barton, C., Willy, R.W. and Morrissey, D., 2019. Biomechanical alterations in individuals with Achilles tendinopathy during running and hopping: A systematic review with meta-analysis. Gait & posture, 73, pp.189-201.
• Sancho, I., Morrissey, D., Willy, R.W., Barton, C. and Malliaras, P., 2019. Education and exercise supplemented by a pain-guided hopping intervention for male recreational runners with midportion Achilles tendinopathy: a single cohort feasibility study. Physical Therapy in Sport, 40, pp.107-116.