Assessment of Shoulder Proprioception in the Female Softball Athlete

Abstract

Background: There have been reports of overhand throwing athletes having decreased joint position sense in their dominant shoulder as compared with the nondominant shoulder. Very little research, however, exists concerning joint position sense in the female athlete.

Hypothesis: Female softball athletes have decreased joint position sense in their dominant shoulder as compared with their nondominant shoulder.

Study Design: Factorial design with investigation of multiple independent variables.

Methods: Joint position sense was assessed in 50 female softball players and 50 nonthrowing female athletes by using an inclinometer during four glenohumeral joint motions. Both the dominant and nondominant shoulders were assessed and error scores were calculated to describe joint position sense. Data were collected during the course of a fall semester and analyzed by using a mixed model analysis of variance with repeated measures on the dependent variable (error scores).

Results: A significant group by movement interaction was observed, with the softball athletes demonstrating significantly greater external rotation error scores than the nonthrowing athletes.

Conclusion: We failed to reject the null hypothesis. Increased error scores (less joint position sense) were observed in both arms of subjects in the softball group.

Clinical Relevance: This study suggests that there is decreased shoulder proprioception in asymptomatic female athletes involved in overyhand throwing sports, which may predispose them to injury.