title: Metabolic, cardiopulmonary, and gait profiles of recently injured and noninjured runners.
abstract: OBJECTIVE
  To examine whether runners recovering from a lower body musculoskeletal injury have different metabolic, cardiopulmonary, and gait responses compared with healthy runners.
  
  
  METHODS
  Cross-sectional study.
  
  
  METHODS
  Research laboratory at an academic institution.
  
  
  METHODS
  Healthy runners (n = 50) were compared with runners who were recently injured but had returned to running (n = 50). Both groups were participating in similar cross-training modalities such as swimming, weight training, biking, and yoga. Running gait was analyzed on a treadmill using 3-dimensional motion capture, and metabolic and cardiopulmonary measures were captured simultaneously with a portable metabolic analyzer.
  
  
  METHODS
  Rate of oxygen consumption, heart rate, ventilation, carbohydrate and fat oxidation values, gait temporospatial parameters and range of motion measures (ROM) in the sagittal plane, energy expenditure, and vertical displacement of the body's center of gravity (COG).
  
  
  RESULTS
  The self-selected running speed was different between the injured and healthy runners (9.7 ± 1.1 km/h and 10.6 ± 1.1 km/h, respectively; P = .038). No significant group differences were noted in any metabolic or cardiopulmonary variable while running at the self-selected or standard speed (13.6 km/h). The vertical displacement of the COG was less in the injured group (8.4 ± 1.4 cm and 8.9 ± 1.4, respectively; P = .044). ROM about the right ankle in the sagittal plane at the self-selected running speed during the gait cycle was less in the injured runners compared with the healthy runners (P < .05).
  
  
  CONCLUSIONS
  Runners with a recent lower body injury who have returned to running have similar cardiopulmonary and metabolic responses to running as healthy runners at the self-selected and standard speeds; this finding may be due in part to participation in cross-training modes that preserve cardiopulmonary and metabolic adaptations. Injured runners may conserve motion by minimizing COG displacement and ankle joint ROM during a gait cycle.
authors.affiliation: Department of Orthopaedics and Rehabilitation, Interdisciplinary Center for Musculoskeletal Training and Research, University of Florida, Gainesville, FL(∗).
authors.forename: Lucinda
authors.initials: L
authors.lastname: Peng
authors.affiliation: Department of Orthopaedics and Rehabilitation, Interdisciplinary Center for Musculoskeletal Training and Research, University of Florida, Gainesville, FL†
authors.forename: Amanda N
authors.initials: AN
authors.lastname: Seay
authors.affiliation: Department of Orthopaedics and Rehabilitation, Interdisciplinary Center for Musculoskeletal Training and Research, University of Florida, Gainesville, FL(‡).
authors.forename: Cindy
authors.initials: C
authors.lastname: Montero
authors.affiliation: Department of Orthopaedics and Rehabilitation, Interdisciplinary Center for Musculoskeletal Training and Research, University of Florida, Gainesville, FL(§).
authors.forename: Leslie L
authors.initials: LL
authors.lastname: Barnes
authors.affiliation: Department of Orthopaedics and Rehabilitation, Interdisciplinary Center for Musculoskeletal Training and Research, University of Florida, Gainesville, FL(¶).
authors.forename: Kevin R
authors.initials: KR
authors.lastname: Vincent
authors.affiliation: Department of Orthopaedics and Rehabilitation, Interdisciplinary Center for Musculoskeletal Training and Research, University of Florida, Gainesville, FL(#).
authors.forename: Bryan P
authors.initials: BP
authors.lastname: Conrad
authors.affiliation: Department of Orthopaedics and Rehabilitation, Interdisciplinary Center for Musculoskeletal Training and Research, University of Florida, Gainesville, FL(∗∗).
authors.forename: Cong
authors.initials: C
authors.lastname: Chen
authors.affiliation: Department of Orthopedics and Rehabilitation, Division of Research, University of Florida Orthopaedics and Sports Medicine Institute, Gainesville, FL(††). Electronic address: vincehk@ortho.ufl.edu.
authors.forename: Heather K
authors.initials: HK
authors.lastname: Vincent
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001265:Athletic Injuries / Q000378:metabolism* / Q000503:physiopathology; D001696:Biomechanical Phenomena; D003430:Cross-Sectional Studies; D004734:Energy Metabolism / Q000502:physiology*; D005260:Female; D005684:Gait / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010101:Oxygen Consumption; D016059:Range of Motion, Articular / Q000502:physiology*; D012420:Running / Q000293:injuries*; D055815:Young Adult