TY - JOUR
T1 - Mechanical Linkage between Achilles Tendon and Plantar Fascia Accounts for Range of Motion of Human Ankle-Foot Complex
AU - Shiotani, Hiroto
AU - Takahashi, Katsuki
AU - Honma, Yuki
AU - Tomari, Kazuki
AU - Hayashi, Hidetaka
AU - Sado, Natsuki
AU - Kawakami, Yasuo
N1 - Funding Information:
This study was a part of the research activities of the Human Performance Laboratory, Comprehensive Research Organization, Waseda University. This work was supported by the JSPS KAKENHI Grant-in-Aid for Research Activity Start-Up (grant no. 21K21231). The authors express their gratitude to Mr. Kyoji Ohta (Technical Management Office, Waseda University) for his technical support in the protocol creation of magnetic resonance imaging scan and Prof. Tsukasa Kumai (Faculty of Sport Sciences, Waseda University) for his comments and suggestions on this study.
Publisher Copyright:
© Lippincott Williams & Wilkins.
PY - 2023/1/1
Y1 - 2023/1/1
N2 - Purpose The human ankle-foot complex possesses a passive range of motion (ROM) through changes in tibiocalcaneal (θcal) and foot arch (θarch) angles. Based on the anatomical linkage between the Achilles tendon (AT) and plantar fascia (PF), we hypothesized that AT and PF with different mechanical properties conjointly modulate the passive ROM of the human ankle-foot complex. We examined the association of AT and PF stiffness with passive ankle-foot ROM and further addressed differences between sexes. Methods A series of sagittal magnetic resonance images of the foot and passive ankle plantar flexion torque were obtained for 20 men and 20 women with their ankle-foot passively rotated from 30° of plantar flexion to 20° of dorsiflexion. Based on the measured changes in AT and PF lengths, θcal, θarch, and passive torque, AT and PF stiffness were determined. Results Upon passive ankle dorsiflexion, AT and PF were lengthened; their length changes were inversely correlated. Men showed a stiffer AT, more compliant PF, less calcaneal rotation, and greater foot arch deformation compared with women. Furthermore, we found inverse correlations between AT stiffness and ROM of θcal, and between PF stiffness and ROM of θarch in men and women. Conclusions Passive AT and PF extensibility counter each other. AT and PF stiffness and passive ROM of ankle-foot components were countered between sexes; however, associations between stiffness and passive ROM of the ankle-foot complex were consistent between sexes. Our findings support the notion that the balanced mechanical interaction between the AT and PF can account for the passive ROM of the human ankle-foot complex in vivo, and the differences between sexes.
AB - Purpose The human ankle-foot complex possesses a passive range of motion (ROM) through changes in tibiocalcaneal (θcal) and foot arch (θarch) angles. Based on the anatomical linkage between the Achilles tendon (AT) and plantar fascia (PF), we hypothesized that AT and PF with different mechanical properties conjointly modulate the passive ROM of the human ankle-foot complex. We examined the association of AT and PF stiffness with passive ankle-foot ROM and further addressed differences between sexes. Methods A series of sagittal magnetic resonance images of the foot and passive ankle plantar flexion torque were obtained for 20 men and 20 women with their ankle-foot passively rotated from 30° of plantar flexion to 20° of dorsiflexion. Based on the measured changes in AT and PF lengths, θcal, θarch, and passive torque, AT and PF stiffness were determined. Results Upon passive ankle dorsiflexion, AT and PF were lengthened; their length changes were inversely correlated. Men showed a stiffer AT, more compliant PF, less calcaneal rotation, and greater foot arch deformation compared with women. Furthermore, we found inverse correlations between AT stiffness and ROM of θcal, and between PF stiffness and ROM of θarch in men and women. Conclusions Passive AT and PF extensibility counter each other. AT and PF stiffness and passive ROM of ankle-foot components were countered between sexes; however, associations between stiffness and passive ROM of the ankle-foot complex were consistent between sexes. Our findings support the notion that the balanced mechanical interaction between the AT and PF can account for the passive ROM of the human ankle-foot complex in vivo, and the differences between sexes.
KW - JOINT FLEXIBILITY
KW - MAGNETIC RESONANCE IMAGING
KW - MEDIAL LONGITUDINAL ARCH OF THE FOOT
KW - SEX DIFFERENCE
KW - STIFFNESS
KW - TRICEPS SURAE MUSCLE-TENDON UNIT
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U2 - 10.1249/MSS.0000000000003020
DO - 10.1249/MSS.0000000000003020
M3 - Article
C2 - 35977106
AN - SCOPUS:85144457570
SN - 0195-9131
VL - 55
SP - 66
EP - 73
JO - Medicine and Science in Sports and Exercise
JF - Medicine and Science in Sports and Exercise
IS - 1
ER -