Ketola S, Lehtinen J, Arnala I, Nissinen M, Westenius H, Sintonen H, Aronen P, Konttinen YT, Malmivaara A, Rousi T.
Does arthroscopic acromioplasty provide any additional value in the treatment of shoulder impingement syndrome? A two-year randomised controlled trial.
J Bone Joint Surg Br 2009 Oct;91(10):1326-1334.

Ketola S, Lehtinen J, Rousi T, Nissinen M, Huhtala H, Konttinen YT, Arnala I.
No evidence of long-term benefits of arthroscopic acromioplasty in the treatment of shoulder impingement syndrome: Five-year results of a randomised controlled trial.
Bone Joint Res 2013 Jul 1;2(7):132-139.

Ketola S, Lehtinen J, Arnala I.
Nonoperative treatment proven superior to decompression in the treatment of anterolateral shoulder pain. A randomised controlled 12-year follow-up. Submitted.

Hannah, D. C.
A Comparison of Strength and Resistance Curves for the Internal and External Rotators of the Shoulder. (2002).
Electronic Theses and Dissertations. Paper 680. http://dc.etsu.edu/etd/680