Trunk-pelvis motion, joint loads, and muscle forces during walking with a transtibial amputation.
People with unilateral, transtibial amputation (TTA) have an increased prevalence of chronic low back pain (LBP) relative to able-bodied people. However, a definitive cause of increased LBP susceptibility has not been determined. The purpose of this work was to compare dynamic trunk-pelvis biomechanics between people with (n=6) and without (n=6) unilateral TTA during walking using a computational modeling approach. A generic, muscle-actuated whole body model was scaled to each participant, and experimental walking data were used in a static optimization framework to calculate trunk-pelvis motion, L4L5 joint contact forces, and muscle forces within the trunk-pelvis region. Results included several significant between-group differences in trunk-pelvis biomechanics during different phases of the gait cycle. Most significant was greater lateral bending toward the residual side during residual single-limb stance (p<0.01), concurrent with an elevated L4L5 joint contact force (p=0.02) and greater muscle force from the intact-side obliques (p<0.01) in people with TTA relative to able-bodied people. During both double-limb support phases, people with TTA also had a greater range of axial trunk rotation away from the leading limb, concurrent with greater ranges of muscle forces in the erector spinae and obliques. In addition, a greater range of force (p=0.03) in residual-side psoas was found during early residual limb swing in people with TTA. Repeated exposure to atypical motion and joint/muscle loading in people with TTA may contribute to the development of secondary musculoskeletal disorders, including chronic, mechanical LBP.
Functional Biomechanics Laboratory, Department of Mechanical Engineering, Colorado School of Mines, Golden, CO 80401, USA.
Adam J
AJ
Yoder
Functional Biomechanics Laboratory, Department of Mechanical Engineering, Colorado School of Mines, Golden, CO 80401, USA.
Anthony J
AJ
Petrella
Functional Biomechanics Laboratory, Department of Mechanical Engineering, Colorado School of Mines, Golden, CO 80401, USA. Electronic address: asilverm@mines.edu.
Anne K
AK
Silverman
D000328:Adult; D000674:Amputees; D001186:Artificial Limbs; D064131:Back Muscles / Q000503:physiopathology; D001696:Biomechanical Phenomena / Q000502:physiology; D016022:Case-Control Studies; D003198:Computer Simulation; D004576:Electromyography; D005684:Gait / Q000502:physiology*; D006801:Humans; D007866:Leg; D017116:Low Back Pain / Q000503:physiopathology; D008954:Models, Biological; D010388:Pelvis / Q000502:physiology*; D060726:Torso / Q000502:physiology*; D016138:Walking / Q000502:physiology*; D021801:Zygapophyseal Joint / Q000503:physiopathology*
Biomechanics; Locomotion; Low back pain; Musculoskeletal modeling; Static optimization