The primary purpose of this study was to examine how the type and magnitude of changes in running behavior, as a consequence of COVID-19 pandemic restrictions, influence running-related injuries. Secondarily, we aimed to examine how lifestyle and psychosocial well-being measures may influence running behavior change. An online survey was advertised to individuals over the age of 18 that currently run or have previously participated in running for exercise. The survey questions examined injury history and new injuries sustained during COVID-19 restrictions, as well as changes related to training behavior changes, training environment changes, social behaviors, and psychosocial well-being. Changes reflected differences in running behaviors prior to COVID-19 restrictions (1 month prior to COVID-19 restrictions being imposed) and during COVID-19 restrictions (May 5 to June 10, 2020). A total of 1,035 runners were included in the analysis. Current injuries sustained during COVID-19 occurred in 9.5% of the runners. Injured runners made a greater number of total changes (p = 0.031) as well as training-related (p = 0.042) and environment-related (p = 0.017) changes compared with uninjured runners. A significant relationship was found between injury and those that reported less time to exercise to changes in work environment (p = 0017). This study highlights the multi-dimensional nature of running-related injuries and the need to consider the interaction of multiple changes in running behavior, rather than isolating single factors. Greater understanding of the underlying causes of running-related injuries can help reduce the risk of future injury.

Walking is an integral indicator of human health commonly investigated while walking overground and with the use of a treadmill. Unlike fixed-speed treadmills, overground walking is dependent on the preferred walking speed under the individuals’ control. Thus, user-driven treadmills may have the ability to better simulate the characteristics of overground walking. This pilot study is the first investigation to compare a user-driven treadmill, a fixed-speed treadmill, and overground walking to understand differences in variability and mean spatiotemporal measures across walking environments. Participants walked fastest overground compared to both fixed and user-driven treadmill conditions. However, gait cycle speed variability in the fixed-speed treadmill condition was significantly lower than the user-driven and overground conditions, with no significant differences present between overground and user-driven treadmill walking. The lack of differences in variability between the user-driven treadmill and overground walking may indicate that the user-driven treadmill can better simulate the variability of overground walking, potentially leading to more natural adaptation and motor control patterns of walking.

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Holmes, HH, Downs Talmage, JL, Neely, KA, and Roper, JA. Cognitive demands influence drop jump performance and relationships with leg stiffness in healthy young adults. J Strength Cond Res 37(1): 74–83, 2023—Sports-relevant cognition influences neuromuscular control and sports performance. This study assessed the influence of cognition on (a) drop jump performance and (b) commonly researched relationships between lower extremity stiffness, ground contact time (GCT), peak vertical ground reaction force (vGRF), and leg deformation. Active adults (n = 33, 13 men, 20 women, 21 ± 2 years, height = 1.71 ± 0.81 m, body mass = 70.5 ± 10.6 kg) participated in decisions to perform drop jumps or lands of a 30-cm box in 4 conditions: (a) standard, explicit instructions; (b) choice, internally driven decisions; and (c and d) visual and audio, external visual or audio cues reducing time for motor planning. Significance was set at p < 0.05. Ground contact time with audio (M ± SD: 0.62 ± 0.14 seconds) and visual cues (0.59 ± 0.10 seconds) was longer than standard instructions (0.54 ± 0.10 seconds). Standard condition jump height was higher (0.49 ± 0.10 m) than audio (0.435 ± 0.10 m) and choice (0.44 ± 0.09 m). Standard condition reactive strength index was higher (1.03 ± 0.35) than audio (0.76 ± 0.23), visual (0.82 ± 0.27), and choice (0.84 ± 0.33). Visual and audio conditions did not demonstrate significant relationships between leg stiffness and GCT, and relationships between vGRF and leg deformation were not significant with visual cues (p > 0.05). Cognition did not significantly change stiffness and vGRF, indicating alternative force strategies. Understanding how cognition influences performance can positively affect coaching practices, sports-specific assessments, and rehabilitation applications.