Vertical Loading Rate Is Not Associated with Running Injury, Regardless of Calculation Method

• Published in: Medicine and science in sports and exercise 2022-08, Vol.54 (8), p.1382-1388
• Main Authors: SCHMIDA, ELIZABETH A., WILLE, CHRISTA M., STIFFLER-JOACHIM, MIKEL R., KLIETHERMES, STEPHANIE A., HEIDERSCHEIT, BRYAN C.
• Format: Article
• Language: English
• Subjects: Biomechanical Phenomena; Gait; Humans; Reinjuries; Running - injuries
• ISSN: 0195-9131; 1530-0315
• DOI: 10.1249/MSS.0000000000002917

Loading rate (LR), the slope of the vertical ground reaction force (vGRF), is commonly used to assess running-related injury risk. However, the relationship between LR and running-related injuries, including bone stress injuries (BSI), is unclear. Inconsistent findings may result from the numerous LR calculation methods that exist and their application across different running speeds. This study aimed to assess the influence of calculation method and running speed on LR values and to determine the association of LR during healthy running with subsequent injury. Healthy preseason running data and subsequent injury records from Division I cross-country athletes ( n = 79) over four seasons (2015-2019) at 2.68 m·s -1 , preferred training pace, and 4.47 m·s -1 were collected. LR at each speed was calculated four ways: 1) maximum and 2) average slope from 20% to 80% of vGRF magnitude at impact peak (IP), 3) average slope from initial contact to IP, and 4) average slope from 3% to 12% of stance time. Linear mixed effects models and generalized estimation equations were used to assess LR associations. LR values differed depending on speed and calculation method ( P value