J A Sampson1, A Murray2, S Williams3, T Halseth2, J Hanisch4, G Golden2, H H K Fullagar5. 1. Centre for Human and Applied Physiology, School of Medicine, University of Wollongong, Australia. Electronic address: jsampson@uow.edu.au. 2. Department of Athletics (Football), University of Oregon, United States. 3. Department for Health, University of Bath, UK. 4. Philadelphia Eagles, United States. 5. Department of Athletics (Football), University of Oregon, United States; Sport & Exercise Discipline Group, University of Technology Sydney, Australia.
Abstract
OBJECTIVES: To determine injury risk-workload associations in collegiate American Football. DESIGN: Retrospective analysis. METHODS: Workload and injury data was recorded from 52 players during a full NCAA football season. Acute, chronic, and a range of acute:chronic workload ratios (ACWR: 7:14, 7:21 and 7:28 day) calculated using rolling and exponentially weighted moving averages (EWMA) were plotted against non-contact injuries (regardless of time lost or not) sustained within 3- and 7-days. Injury risks were also determined relative to position and experience. RESULTS: 105 non-contact injuries (18 game- and 87 training-related) were observed with almost 40% sustained during the pre-season. 7-21 day EWMA ACWR's with a 3-day injury lag were most closely associated with injury (R2=0.54). Relative injury risks were >3× greater with high compared to moderate and low ratios and magnified when combined with low 21-day chronic workloads (injury probability=92.1%). Injury risks were similar across positions. 'Juniors' presented likely and possibly increased overall injury risk compared to 'Freshman' (RR: 1.94, CI 1.07-3.52) and 'Seniors' (RR: 1.7, CI 0.92-3.14), yet no specific ACWR - experience or - position interactions were identified. CONCLUSIONS: High injury rates during college football pre-season training may be associated with high acute loads. In-season injury risks were greatest with high ACWR and evident even when including (more common and less serious) non-time loss injuries. Substantially increased injury risks when low 21-day chronic workloads and concurrently high EWMA ACWR highlights the importance of load management for individuals with chronic game- (non-involved on game day) and or training (following injury) absences.
OBJECTIVES: To determine injury risk-workload associations in collegiate American Football. DESIGN: Retrospective analysis. METHODS: Workload and injury data was recorded from 52 players during a full NCAA football season. Acute, chronic, and a range of acute:chronic workload ratios (ACWR: 7:14, 7:21 and 7:28 day) calculated using rolling and exponentially weighted moving averages (EWMA) were plotted against non-contact injuries (regardless of time lost or not) sustained within 3- and 7-days. Injury risks were also determined relative to position and experience. RESULTS: 105 non-contact injuries (18 game- and 87 training-related) were observed with almost 40% sustained during the pre-season. 7-21 day EWMA ACWR's with a 3-day injury lag were most closely associated with injury (R2=0.54). Relative injury risks were >3× greater with high compared to moderate and low ratios and magnified when combined with low 21-day chronic workloads (injury probability=92.1%). Injury risks were similar across positions. 'Juniors' presented likely and possibly increased overall injury risk compared to 'Freshman' (RR: 1.94, CI 1.07-3.52) and 'Seniors' (RR: 1.7, CI 0.92-3.14), yet no specific ACWR - experience or - position interactions were identified. CONCLUSIONS: High injury rates during college football pre-season training may be associated with high acute loads. In-season injury risks were greatest with high ACWR and evident even when including (more common and less serious) non-time loss injuries. Substantially increased injury risks when low 21-day chronic workloads and concurrently high EWMA ACWR highlights the importance of load management for individuals with chronic game- (non-involved on game day) and or training (following injury) absences.
Authors: Amanda Esquivel; Michael T Freehill; Frank C Curriero; Kevin L Rand; Stan Conte; Thomas Tedeschi; Stephen E Lemos Journal: Orthop J Sports Med Date: 2019-12-27
Authors: Johann Windt; Clare L Ardern; Tim J Gabbett; Karim M Khan; Chad E Cook; Ben C Sporer; Bruno D Zumbo Journal: BMJ Open Date: 2018-10-02 Impact factor: 2.692