Grounded Running Reduces Musculoskeletal Loading

• Published in: Medicine and science in sports and exercise 2019-04, Vol.51 (4), p.708-715
• Main Authors: BONNAERENS, SENNE, FIERS, PIETER, GALLE, SAMUEL, AERTS, PETER, FREDERICK, EDWARD C, KANEKO, YASUNORI, DERAVE, WIM, DE CLERCQ, DIRK
• Format: Article
• Language: English
• Subjects: Acceleration; Biomechanical Phenomena; Energy Metabolism; Gait - physiology; Humans; Male; Musculoskeletal Physiological Phenomena; Risk Factors; Running - injuries; Running - physiology; Stress, Mechanical; Tibia - physiology
• ISSN: 0195-9131; 1530-0315
• DOI: 10.1249/MSS.0000000000001846

PURPOSERecent observations demonstrate that a sizeable proportion of the recreational running population runs at rather slow speeds and does not always show a clear flight phase. This study determined the key biomechanical and physiological characteristics of this running pattern, i.e., grounded running (GR), and compared these characteristics with slow aerial running (SAR) and reference data on walking at the same slow running speed. METHODSThirty male subjects performed instructed GR and SAR at 2.10 m·s on a treadmill. Ground reaction forces, tibial accelerations, and metabolic rate were measured to estimate general musculoskeletal loading (external power and maximal vertical ground reaction force), impact intensity (vertical instantaneous loading rate and tibial acceleration), and energy expenditure. More explicit measures of muscular loading (muscle stresses and peak eccentric power) were calculated based on a representative subsample, in which detailed kinematics and kinetics were recorded. We hypothesized that all measures would be lower for the GR condition. RESULTSSubjects successfully altered their running pattern upon a simple instruction toward a GR pattern by increasing their duty factor from 41.5% to 51.2%. As hypothesized, impact intensity, general measures for musculoskeletal, and the more explicit measures for muscular loading decreased by up to 35.0%, 20.3%, and 34.0%, respectively, compared with SAR. Contrary to our hypothesis, metabolic rate showed an increase of 4.8%. CONCLUSIONSChanging running style from SAR to GR reduces musculoskeletal loading without lowering the metabolic energy requirements. As such, GR might be beneficial for most runners as it has the potential to reduce the risk of running-related injuries while remaining a moderate to vigorous form of physical activity, contributing to fulfillment of the recommendations concerning physical activity and public health.