TY - JOUR
T1 - Knee kinematic profiles during drop landings
T2 - A biplane fluoroscopy study
AU - Torry, Michael R.
AU - Shelburne, Kevin B.
AU - Peterson, Daniel S.
AU - Giphart, J. Erik
AU - Krong, Jacob P.
AU - Myers, Casey
AU - Steadman, J. Richard
AU - Woo, Savio L.Y.
N1 - Copyright:
Copyright 2011 Elsevier B.V., All rights reserved.
PY - 2011/3
Y1 - 2011/3
N2 - Introduction: The six degrees of freedom knee motion during dynamic activities is not well understood. Purpose: Biplane fluoroscopy was used to measure the three-dimensional rotations and translations of healthy knees during stiff drop landings and to determine the relationships between three-dimensional rotations and anterior (ATT) and lateral tibial translations (LTT). Methods: Six males performed stiff drop landings from 40 cm while being filmed using a high-speed, biplane fluoroscopy system. Initial, peak, and excursions for rotations and translations were calculated, and relationships and changes in these variables were assessed (α = 0.05). Results: Knee flexion at contact was 13.9° ± 9.2° (mean ± SD) and increased to a peak of 44.0° ± 17.2° with an excursion of 31.5° ± 14.1°. Knee varus/valgus angle at contact was -0.3° ± 1.8° varus; subjects progressed into a mean peak valgus position of 1.5° ± 0.9° with total excursion of 2.5° ± 0.9°. Four of six subjects landed externally rotated (2.5° ± 3.0°); two landed internally rotated (-4.9° ± 1.5°), yielding a contact angle of -2.4° ± 3.0° of internal rotation, a peak internal rotation of -5.5° ± 6.0°, and excursion of 3.1° ± 5.5°. Peak ATT were 4.3 ± 0.7 mm (excursion = 2.1 ± 0.9 mm), occurring within 50 ms after contact. Peak LTT were 1.5 ± 1.4 mm (excursion = 2.6 ± 1.6 mm). Significant regressions were found between ATT and knee valgus angle (r = 0.39, P = 0.006), between LTT and internal rotation (r = 0.96, P < 0.0001), and between LTT and knee valgus angle (quadratic, r = 0.90, P < 0.0001). Conclusion: This study provides a direct correlation between knee valgus angle with knee ATT and LTT during drop landings.
AB - Introduction: The six degrees of freedom knee motion during dynamic activities is not well understood. Purpose: Biplane fluoroscopy was used to measure the three-dimensional rotations and translations of healthy knees during stiff drop landings and to determine the relationships between three-dimensional rotations and anterior (ATT) and lateral tibial translations (LTT). Methods: Six males performed stiff drop landings from 40 cm while being filmed using a high-speed, biplane fluoroscopy system. Initial, peak, and excursions for rotations and translations were calculated, and relationships and changes in these variables were assessed (α = 0.05). Results: Knee flexion at contact was 13.9° ± 9.2° (mean ± SD) and increased to a peak of 44.0° ± 17.2° with an excursion of 31.5° ± 14.1°. Knee varus/valgus angle at contact was -0.3° ± 1.8° varus; subjects progressed into a mean peak valgus position of 1.5° ± 0.9° with total excursion of 2.5° ± 0.9°. Four of six subjects landed externally rotated (2.5° ± 3.0°); two landed internally rotated (-4.9° ± 1.5°), yielding a contact angle of -2.4° ± 3.0° of internal rotation, a peak internal rotation of -5.5° ± 6.0°, and excursion of 3.1° ± 5.5°. Peak ATT were 4.3 ± 0.7 mm (excursion = 2.1 ± 0.9 mm), occurring within 50 ms after contact. Peak LTT were 1.5 ± 1.4 mm (excursion = 2.6 ± 1.6 mm). Significant regressions were found between ATT and knee valgus angle (r = 0.39, P = 0.006), between LTT and internal rotation (r = 0.96, P < 0.0001), and between LTT and knee valgus angle (quadratic, r = 0.90, P < 0.0001). Conclusion: This study provides a direct correlation between knee valgus angle with knee ATT and LTT during drop landings.
KW - ACL
KW - anterior tibial translation
KW - biomechanics
KW - valgus collapse
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U2 - 10.1249/MSS.0b013e3181f1e491
DO - 10.1249/MSS.0b013e3181f1e491
M3 - Article
C2 - 20689456
AN - SCOPUS:79952100585
VL - 43
SP - 533
EP - 541
JO - Medicine and Science in Sports and Exercise
JF - Medicine and Science in Sports and Exercise
SN - 0195-9131
IS - 3
ER -