title: Biomechanical strategies implemented to compensate for mild leg length discrepancy during gait.
abstract: Although mild leg length discrepancy is related to lower limb injuries, there is no consensus regarding its effects on the biomechanics of the lower limbs during gait. Biomechanical data of 19 healthy participants were collected while they walked under different conditions as described: (1) control condition-wearing flat thick sandals; (2) short limb condition-wearing a flat thick sandal on the left and a flat thin sandal on the right foot; (3) long limb condition: wearing flat thin sandal on the left and flat thick sandal on the right foot. The thick and thin sandals had 1.45cm of mean thickness difference. The right lower limb data were analyzed for all conditions. Ankle, knee, hip and pelvis kinematics and internal moments were measured with a motion capture system and six force platforms. Principal component analysis was used to compare differences between conditions. The scores of the principal components were compared between conditions using one-way repeated measures ANOVA. Twelve gait variables were different between conditions: rearfoot dorsiflexion and inversion (p<0.001); ankle dorsiflexion and inversion moments (p<0.001); knee flexion angle and moment (p<0.001); knee adduction moment (p<0.001); hip flexion angle and moment (p<0.001); hip adduction angle (p=0.001) and moment (p=0.022); and pelvic ipsilateral drop (p<0.001). Mild leg length discrepancy caused compensatory changes during gait, apparently to equalize the functional length of the lower limbs. However, these strategies did not fully succeed, since both short and long limb conditions affected pelvic motion in the frontal plane. These results suggest that mild leg length discrepancy should not be overlooked in clinical settings.
authors.affiliation: Universidade Federal de Minas Gerais, School of Physical Education, Physical Therapy and Occupational Therapy, Department of Physical Therapy, Avenida Antônio Carlos 6627 Campus Pampulha, Pampulha, 31270-901 Belo Horizonte, MG, Brazil. Electronic address: renanresende@hotmail.com.
authors.forename: Renan A
authors.initials: RA
authors.lastname: Resende
authors.affiliation: Wilfrid Laurier University, 75 University Avenue W, Waterloo, N2L 3C5, ON, Canada. Electronic address: renata.kirkwood@gmail.com.
authors.forename: Renata N
authors.initials: RN
authors.lastname: Kirkwood
authors.affiliation: Queen's University, McLaughlin Hall, Faculty of Engineering and Applied Science, Department of Mechanical and Materials Engineering, Kingston, ON, Canada. Electronic address: kevin.deluzio@queensu.ca.
authors.forename: Kevin J
authors.initials: KJ
authors.lastname: Deluzio
authors.affiliation: U Lisboa, Fac Motricidade Humana, CIPER, LBMF, P-1499-002, Lisboa, Portugal. Electronic address: scabral@fmh.ulisboa.pt.
authors.forename: Silvia
authors.initials: S
authors.lastname: Cabral
authors.affiliation: Universidade Federal de Minas Gerais, School of Physical Education, Physical Therapy and Occupational Therapy, Department of Physical Therapy, Avenida Antônio Carlos 6627 Campus Pampulha, Pampulha, 31270-901 Belo Horizonte, MG, Brazil. Electronic address: sergioteixeirafonseca@gmail.com.
authors.forename: Sérgio T
authors.initials: ST
authors.lastname: Fonseca
mesh_terms: D000328:Adult; D001696:Biomechanical Phenomena; D005260:Female; D005684:Gait / Q000502:physiology*; D006801:Humans; D007870:Leg Length Inequality / Q000503:physiopathology*; D035002:Lower Extremity / Q000503:physiopathology*; D008297:Male; D010388:Pelvis / Q000503:physiopathology*; D016059:Range of Motion, Articular; D016138:Walking
keywords: Biomechanics; Gait; Leg length discrepancy; Lower limbs