The Effect of the Number of Carries Among College Running Backs on Future Injury Risk and Performance in the National Football League

BACKGROUND: There has been speculation that running backs with an excessive number of carries in college are less likely to be successful in the National Football League (NFL). PURPOSE: To determine whether there is a correlation between number of carries by college running backs and future performance and injury risk in the NFL. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: Using the ESPN archives of National Collegiate Athletic Association and NFL running backs, the following inclusion criteria were used: running backs who played their last college season from 1999 through 2012 and who were drafted in the first 4 rounds of the NFL draft following their college career. Players were grouped by number of carries during their final college season (group A, 100-200 carries; group B, 250+ carries). Performance and injury risk were compared between groups during the first 3 eligible seasons in the NFL. Groups were compared based on total number of carries, mean yards per carry, number of games missed due to injury, and the specific injuries resulting in missed playing time. RESULTS: During the seasons studied, a total of 103 running backs were included (group A, n = 42; group B, n = 61). There was a trend toward a significantly greater mean total number of carries through 3 NFL seasons in group B (group A, n = 276 carries; group B, n = 376 carries; P = .058). Mean yards per carry did not differ between groups (group A, n = 3.9 yards/carry; group B, n = 4.0 yards/carry; P = .67). Groups A and B missed a mean 5.8 and 5.7 games, respectively, due to injury during their first 3 NFL seasons (P = .98). A significantly greater proportion of players in group A suffered a concussion compared with group B (P = .014). CONCLUSION: There is no correlation between the number of carries by college running backs and future injury risk or performance during their early NFL career.