title: Evidence for joint moment asymmetry in healthy populations during gait.
abstract: The purpose of this study was to determine the presence and prevalence of asymmetry in lower extremity joint moments within and across healthy populations during overground walking. Bilateral gait data from several studies performed at two institutions were pooled from 182 healthy, pain-free subjects. Four distinct populations were identified based on age, activity level and body mass index. Mean peak external joint moments were calculated from three to six trials of level overground walking at self-selected speed for each subject. Right and left limb moments were reclassified as "greater" or "lesser" moment for each subject to prevent obscuring absolute asymmetry due to averaging over positive and negative asymmetries across subjects. A clinically relevant asymmetry measure was calculated from the peak joint moments with an initial chosen cutoff value of 10%. Confidence intervals for the proportion of subjects with greater than 10% asymmetry between limbs were estimated based on the binomial distribution. We found a high amount of asymmetry between the limbs in healthy populations. More than half of our overall population exceeded 10% asymmetry in peak hip and knee flexion and adduction moments. Group medians exceeded 10% asymmetry for all variables in all populations. This may have important implications on gait evaluations, particularly clinical evaluations or research studies where asymmetry is used as an outcome. Additional research is necessary to determine acceptable levels of joint moment asymmetry during gait and to determine whether asymmetrical joint moments influence the development of symptomatic pathology or success of lower extremity rehabilitation.
authors.affiliation: Mechanical and Aerospace Engineering, The Ohio State University, Columbus, OH, United States. Electronic address: lambach.2@osu.edu.
authors.forename: Rebecca L
authors.initials: RL
authors.lastname: Lathrop-Lambach
authors.affiliation: Mechanical Engineering, Stanford University, Stanford, CA, United States; Musculoskeletal Research Laboratories, Department of Veterans Affairs, Palo Alto, CA, United States.
authors.forename: Jessica L
authors.initials: JL
authors.lastname: Asay
authors.affiliation: Department of Kinesiology and Applied Physiology, University of Delaware, Newark, DE, United States.
authors.forename: Steve T
authors.initials: ST
authors.lastname: Jamison
authors.affiliation: Center for Biostatistics, The Ohio State University, Columbus, OH, United States.
authors.forename: Xueliang
authors.initials: X
authors.lastname: Pan
authors.affiliation: School of Health and Rehabilitation Sciences, The Ohio State University, Columbus, OH, United States; Sports Health and Performance Institute, The Ohio State University, Columbus, OH, United States.
authors.forename: Laura C
authors.initials: LC
authors.lastname: Schmitt
authors.affiliation: Mechanical Engineering, Stanford University, Stanford, CA, United States; Musculoskeletal Research Laboratories, Department of Veterans Affairs, Palo Alto, CA, United States.
authors.forename: Katerina
authors.initials: K
authors.lastname: Blazek
authors.affiliation: Mechanical and Aerospace Engineering, The Ohio State University, Columbus, OH, United States; Department of Orthopaedics, The Ohio State University, Columbus, OH, United States; School of Health and Rehabilitation Sciences, The Ohio State University, Columbus, OH, United States.
authors.forename: Robert A
authors.initials: RA
authors.lastname: Siston
authors.affiliation: Mechanical Engineering, Stanford University, Stanford, CA, United States; Musculoskeletal Research Laboratories, Department of Veterans Affairs, Palo Alto, CA, United States; Orthopaedic Surgery, Stanford University, Palo Alto, CA, United States.
authors.forename: Thomas P
authors.initials: TP
authors.lastname: Andriacchi
authors.affiliation: Mechanical and Aerospace Engineering, The Ohio State University, Columbus, OH, United States; Department of Orthopaedics, The Ohio State University, Columbus, OH, United States; School of Health and Rehabilitation Sciences, The Ohio State University, Columbus, OH, United States; Sports Health and Performance Institute, The Ohio State University, Columbus, OH, United States.
authors.forename: Ajit M W
authors.initials: AM
authors.lastname: Chaudhari
mesh_terms: D000328:Adult; D000843:Ankle Joint / Q000503:physiopathology*; D000886:Anthropometry; D001696:Biomechanical Phenomena / Q000502:physiology; D005260:Female; D005684:Gait / Q000502:physiology*; D006621:Hip Joint / Q000503:physiopathology*; D006801:Humans; D007719:Knee Joint / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000503:physiopathology
keywords: Gait analysis; Joint mechanics; Rehabilitation