Orthopaedic Department, Hospital del Mar de Barcelona, Barcelona, Spain

Purpose: The objective of the study is to evaluate the correlation between the capacity to perform external rotation and quality of life perception and if this correlation is affected by external rotation strength.

Material and Methods: Prospective study including 78 patients with a mean age of 59,96 years. There were 51 females and 27 males. 36 consulting because gleno humeral arthritis, 24 cuff disorders, 9 fractures and 9 instabilities. All patients completed SF-36 quality of life questionnaire and Constant Score. External rotation strength with the arm at the side (ER1) and with the arm at 90º of anterior elevation (ER2) was recorded with a digital strength tester. Spearman correlations.

Results: Independent of the Constant Score value the ability to perform external rotation correlates with quality of life perception (0,549 PF_norm, 0,418 RP_norm, 0,415 PHY comp). Strength of external rotation correlates less than the ability to perform external rotation with quality of life perception and ER2 has a stronger correlation than ER1 (ER2 : 0,467 PF_norm, 0,240 RP_norm, 0,381 PHY comp and ER1 : 0,326 PF_norm, 0,213 RP_norm, 0,326 PHY comp).

Conclusion: There is a clear correlation between the ability to perform external rotation and the quality of life perception and this correlation is independent of the total Constant Score. The strength of external rotation correlates less with quality of life perception, but the strength at 90º of anterior elevation presents higher correlation than strength with the arm at the side. Muscular transpositions can improve quality of life perception by restoring external rotation ability independent of the strength obtained.