Characteristics of shoulder impingement in the recreational weight-training population.

Despite reports implicating subacromial impingement syndrome (SIS) as an etiologic source of shoulder pain among weight-training (WT) participants, a paucity of case-controlled evidence exists to support this premise. The purpose of this study was to determine whether WT participants present with characteristics of SIS. Additionally, we investigated the role of exercise selection among those identified as having SIS. Seventy-seven (154 shoulders) men (mean age, 28) were recruited, including 46 individuals who engaged in WT a minimum of 2 days per week; and 31 controls with no history of WT participation. Before testing, participants completed a questionnaire summarizing their training patterns. On completing questionnaire, 2 previously validated tests used to identify SIS were performed on both groups and included the painful arc sign and Hawkins-Kennedy test. When clustered, these tests have a positive likelihood ratio of 5.0 for identifying SIS when compared with diagnostic gold standards. Analysis identified significant between-group differences in the combined presence of a positive painful arc and Hawkins-Kennedy (p < 0.001) test. A significant association existed between clinical characteristics of SIS (p ≤ 0.004) and both lateral deltoid raises and upright rows above 90°. Conversely, a significant inverse association was found between external rotator strengthening and characteristics of SIS. Results suggest that WT participants may be predisposed to SIS. Avoiding performance of lateral deltoid raises and upright rows beyond an angle of 90° and efforts to strengthen the external rotators may serve as a useful means to mitigate characteristics associated with SIS.