The purpose of this study is to determine if scapular stabilizer weakness and instability is a plausible explanation for excessive winging and/or tipping of the scapula in females who participate in overhead sports. Instability may be an early sign of weakness that can contribute to shoulder injury. Literature regarding causes of scapular winging and tipping pertaining to weak scapular stabilizer muscle strength in overhead female athletes has not been widely studied. In this study subjects were 18-25 year-old volunteer female college-level athletes that participate in overhead sports. Observational measurements and isokinetic testing were taken to evaluate placement of the scapula and scapular muscle strength. By knowing the correlation of winging and tipping of the scapula and weakness of the scapular stabilizer muscles, prevention of shoulder injury may be feasible. From our findings, we hope to contribute prevention techniques for shoulder injuries to provide strengthening and rehabilitation methods.