title: Influence of a 12.8-km military load carriage activity on lower limb gait mechanics and muscle activity.
abstract: The high stress fracture occurrence in military populations has been associated with frequent load carriage activities. This study aimed to assess the influence of load carriage and of completing a load carriage training activity on gait characteristics. Thirty-two Royal Marine recruits completed a 12.8-km load carriage activity as part of their military training. Data were collected during walking in military boots, pre and post-activity, with and without the additional load (35.5 kg). Ground contact time, lower limb sagittal plane kinematics and kinetics, and electromyographic variables were obtained for each condition. When carrying load, there was increased ground contact time, increased joint flexion and joint moments, and increased plantar flexor and knee extensor muscle activity. Post-activity, there were no changes to kinematic variables, knee extensor moments were reduced, and there was evidence of plantar flexor muscle fatigue. The observed gait changes may be associated with stress fracture development. Practitioner Summary: This study identified gait changes due to load carriage and after a military load carriage training activity. Such activities are associated with lower limb stress fractures. A pre-post study design was used. Gait mechanics changed to a greater extent when carrying load, than after completion of the activity when assessed without load.
authors.affiliation: a School of Sport and Health Sciences , University of Exeter , Exeter , UK.
authors.forename: Hannah
authors.initials: H
authors.lastname: Rice
authors.affiliation: b Institute of Naval Medicine , Alverstoke , UK.
authors.forename: Joanne
authors.initials: J
authors.lastname: Fallowfield
authors.affiliation: b Institute of Naval Medicine , Alverstoke , UK.
authors.forename: Adrian
authors.initials: A
authors.lastname: Allsopp
authors.affiliation: a School of Sport and Health Sciences , University of Exeter , Exeter , UK.
authors.forename: Sharon
authors.initials: S
authors.lastname: Dixon
mesh_terms: D000328:Adult; D000843:Ankle Joint / Q000502:physiology; D001696:Biomechanical Phenomena; D004576:Electromyography; D005684:Gait / Q000502:physiology*; D006801:Humans; D007719:Knee Joint / Q000502:physiology; D017770:Lifting; D035002:Lower Extremity / Q000502:physiology*; D008297:Male; D008889:Military Personnel; D018482:Muscle, Skeletal / Q000502:physiology*; D006113:United Kingdom; D016474:Weight-Bearing; D055815:Young Adult
keywords: EMG; Load carriage; kinematics; kinetics; stress fracture