TY - JOUR
T1 - High muscle co-contraction does not result in high joint forces during gait in anterior cruciate ligament deficient knees
AU - Khandha, Ashutosh
AU - Manal, Kurt
AU - Capin, Jacob
AU - Wellsandt, Elizabeth
AU - Marmon, Adam
AU - Snyder-Mackler, Lynn
AU - Buchanan, Thomas S.
N1 - Funding Information:
This work was supported by the following grants: Eunice Kennedy Shriver National Institute of Child Health And Human Development—R01-HD087459; National Institute of Arthritis And Musculoskeletal And Skin Diseases—R01-AR046386, R01-AR048212; National Institute of General Medical Sciences— P30-GM103333, R37-HD037985, T32-HD007490, U54-GM104941; National Institute For Child Health And Human Development, F30-HD096830; Foundation for Physical Therapy; and Promotion of Doctoral Studies (PODS) – Level I Scholarship.
Funding Information:
Conflicts of interest: No competing financial interests exist for any of the authors. Grant sponsor: National Institute of General Medical Sciences; Grant numbers: P30-GM103333, R37-HD037985, T32-HD007490, U54-GM104941; Grant sponsor: National Institute of Arthritis and Musculoskeletal and Skin Diseases; Grant numbers: R01-AR046386, R01-AR048212; Grant sponsor: Eunice Kennedy Shriver National Institute of Child Health and Human Development; Grant number: R01-HD087459; Grant sponsor: National Institute For Child Health And Human Development; Grant number: F30-HD096830; Grant sponsor: Foundation for Physical Therapy; Grant name: Promotion of Doctoral Studies (PODS) – Level I Scholarship. Correspondence to: Ashutosh Khandha (T: +1-302-831-6774; F: +1-302-831-3619; E-mail: ashutosh@udel.edu)
Publisher Copyright:
© 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.
PY - 2019/1
Y1 - 2019/1
N2 - The mechanism of knee osteoarthritis development after anterior cruciate ligament injuries is poorly understood. The objective of this study was to evaluate knee gait variables, muscle co-contraction indices and knee joint loading in young subjects with anterior cruciate ligament deficiency (ACLD, n = 36), versus control subjects (n = 12). A validated, electromyography-informed model was used to estimate joint loading. For the involved limb of ACLD subjects versus control, muscle co-contraction indices were higher for the medial (p = 0.018, effect size = 0.93) and lateral (p = 0.028, effect size = 0.83) agonist–antagonist muscle pairs. Despite higher muscle co-contraction, medial compartment contact force was lower for the involved limb, compared to both the uninvolved limb (mean difference = 0.39 body weight, p = 0.009, effect size = 0.70) as well as the control limb (mean difference = 0.57 body weight, p = 0.007, effect size = 1.14). Similar observations were made for total contact force. For involved versus uninvolved limb, the ACLD group demonstrated lower vertical ground reaction force (mean difference = 0.08 body weight, p = 0.010, effect size = 0.70) and knee flexion moment (mean difference = 1.32% body weight * height, p = 0.003, effect size = 0.76), during weight acceptance. These results indicate that high muscle co-contraction does not always result in high knee joint loading, which is thought to be associated with knee osteoarthritis. Long-term follow-up is required to evaluate how gait alterations progress in non-osteoarthritic versus osteoarthritic subjects.
AB - The mechanism of knee osteoarthritis development after anterior cruciate ligament injuries is poorly understood. The objective of this study was to evaluate knee gait variables, muscle co-contraction indices and knee joint loading in young subjects with anterior cruciate ligament deficiency (ACLD, n = 36), versus control subjects (n = 12). A validated, electromyography-informed model was used to estimate joint loading. For the involved limb of ACLD subjects versus control, muscle co-contraction indices were higher for the medial (p = 0.018, effect size = 0.93) and lateral (p = 0.028, effect size = 0.83) agonist–antagonist muscle pairs. Despite higher muscle co-contraction, medial compartment contact force was lower for the involved limb, compared to both the uninvolved limb (mean difference = 0.39 body weight, p = 0.009, effect size = 0.70) as well as the control limb (mean difference = 0.57 body weight, p = 0.007, effect size = 1.14). Similar observations were made for total contact force. For involved versus uninvolved limb, the ACLD group demonstrated lower vertical ground reaction force (mean difference = 0.08 body weight, p = 0.010, effect size = 0.70) and knee flexion moment (mean difference = 1.32% body weight * height, p = 0.003, effect size = 0.76), during weight acceptance. These results indicate that high muscle co-contraction does not always result in high knee joint loading, which is thought to be associated with knee osteoarthritis. Long-term follow-up is required to evaluate how gait alterations progress in non-osteoarthritic versus osteoarthritic subjects.
KW - ACL
KW - joint forces
KW - knee
KW - muscle co-contraction
KW - musculoskeletal modeling
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U2 - 10.1002/jor.24141
DO - 10.1002/jor.24141
M3 - Article
C2 - 30230006
AN - SCOPUS:85054648989
VL - 37
SP - 104
EP - 112
JO - Journal of Orthopaedic Research
JF - Journal of Orthopaedic Research
SN - 0736-0266
IS - 1
ER -