Author(s): Spencer Vance
Mentor(s): Malorie Wilwand
Institution BYU
In American football, wide receivers (WR) and defensive backs (DB) are two positions that require speed and agility as they engage in direct one-on-one matchups. However, there may be important differences in player roles unique to the two positions that are influenced by the physical abilities of the players. Understanding the differences in physical characteristics, such as sprint speed (SS), eccentric hamstring strength (EHS), and muscle volume (MV), between offensive and defensive players can help coaches make informed decisions about player development and conditioning strategies to enhance performance in both positions. We hypothesize that there will be a significant difference in SS, EHS, and MV between WR and DB. PURPOSE: This study aims to compare SS, EHS, and MV of the rectus femoris, vastus intermedius, vastus lateralis, and vastus medialis between collegiate football WR and DB. METHODS: This study was a secondary analysis of HAMIR data; NCAA Division I football players who were actively rostered and uninjured at the time of data collection completed the study (n=30; height = 182.48 ± 4.75 cm; weight = 85.84 ± 5.84 kg). Timing gate technology was used to measure the speed of the athlete’s sprint. Sensors were placed at the 0- and 60-yard lines as the athletes sprinted 60 yards. To find the EHS, each athlete completed three Nordic curls on a Nordboard system. The study used MRI to find the MV of each of the muscles with the left and right sides separated. RESULTS: The multivariate analysis of variance comparing SS, EHS, and MV of the quadriceps showed no significant difference (p = 0.31) between WR and DB. CONCLUSION: We observed the measurements of SS, EHS, and muscle sizes do not suggest meaningful differences between the two positions. This contradicts our proposed hypothesis that there would be a significant difference. Not having a difference may be important for success between the two positions. DB want to match the speed and movements of the WR to prevent the success of the offense, while WR want to get open to make receptions and score. This does not decisively indicate, however, that there are no physical differences between the two positions. There are several other attributes of athletic ability and skill that contribute to the success of these positions not covered by this study, such as agility, reaction time, and jumping ability.