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Purpose: To compare stiffness, strain, and load to failure of 4- versus 5-strand hamstring anterior cruciate ligament reconstruction human tendon allografts with femoral suspensory and tibial interference screw fixation Methods: Allograft hamstring tendons were used to create 10 four-strand (4S) and 10 five-strand (5S) grafts. Grafts were fixed to a uniaxial electromechanical load system via a femoral cortical suspensory button and a bioabsorbable interference screw in bone analogue. Grafts were cycled from 100 Newtons (N) to 250 N for 1,000 repetitions at 0.5 hertz before load to failure testing. Cyclic displacement was defined as the difference in graft length from the first 20 to 30 cycles compared with the last 10 cycles. Trials were recorded on a high-definition camera to allow for digital image correlation analysis. Results: Cyclic displacement more than 1,000 cycles was significantly lower in the 4S compared with the 5S group (0.87 vs 1.11 mm, P = .037). Digital image correlation analysis confirmed that the fifth strand elongated more than the other 4 strands in the 5S constructs (6.1% vs 3.9%, P = .032). Load to failure was greater in the 4S compared with the 5S group but not statistically significant (762 vs 707 N, P = .35). Stiffness was similar between constructs (138.5 vs 138.3 N/mm, P = .96) Conclusions: Compared with cyclically loaded 4S hamstring grafts, the 5S grafts had significantly increased displacement over time in a model of femoral suspensory and tibial interference screw fixation. Clinical Relevance: Anterior cruciate ligament reconstruction with hamstring tendon autograft is a commonly performed surgery with excellent outcomes. It has been shown that graft diameter influences these outcomes. As surgeons use larger grafts, it is important to investigate how these constructs may affect the outcomes of surgery.

# Background Ultimate Frisbee is a rapidly growing sport played in all levels of competition in men’s, women’s, and coed divisions. Despite widespread popularity, there remains a lack of research on injury risk and prevalence during a season. # Purpose To determine the prevalence of injuries among elite club-level men and women Ultimate Frisbee players and to identify elements associated with injury during a single season. # Study Design Descriptive epidemiological study. # Methods Voluntary preseason and postseason online surveys were distributed to local elite club-level Ultimate teams in 2019. Surveys assessed players’ lifetime Ultimate-associated injury history, injury status, training regimen, and other related elements. # Results Fifty-seven and 84 players were eligible to complete the preseason and postseason surveys, respectively. Prior to the 2019 season, 97% of female respondents and 100% of male respondents reported a previous Ultimate-related injury in their career, with all reporting a prior lower extremity injury. During the 2019 season, 56% of respondents reported being injured, and 12% missed one month or more of the season, with 88% of injured players reporting a lower extremity injury. Men reported more ankle and calf injuries than women, and there was a strong negative correlation between time missed due to injury during the 2018 season and the number of days per week spent weight-training and accumulated training. # Conclusion There is a high prevalence of lower extremity injury among elite club-level Ultimate players during a single season and pervasive lower extremity injury history may contribute to high injury prevalence. Observed injury patterns suggest targeted interventions including Nordic Hamstring Exercises and balance and proprioceptive training may decrease injury risk. Further research into this topic is needed to help reduce injury in these athletes. # Levels of Evidence Level 3.