Kentaro Chino1, Lilian Lacourpaille2, Jun Sasahara3, Yasuhiro Suzuki4, François Hug5. 1. Sports Okinawa, Urasoe city, Okinawa, Japan; Department of Sports Research, Japan Institute of Sports Sciences, Kita city, Tokyo, Japan. Electronic address: mike04diaz@yahoo.co.jp. 2. Laboratory Movement, Interactions, Performance (EA 4334), Faculty of Sport Sciences, University of Nantes, Nantes, France. 3. Department of Orthopaedic Surgery, Teikyo University Institute of Sports Science and Medicine, Hachioji city, Tokyo, Japan. 4. Department of Sports Research, Japan Institute of Sports Sciences, Kita city, Tokyo, Japan. 5. Laboratory Movement, Interactions, Performance (EA 4334), Faculty of Sport Sciences, University of Nantes, Nantes, France; Institut universitaire de France (IUF), Paris, France.
Abstract
BACKGROUND: The plantar fascia is exposed to repetitive tensile stress induced by cyclic loads associated with daily activities, such as walking and running. Due to overuse or abnormal foot alignment, insertional and distal (i.e., mid-substance) regions within the plantar fascia may exhibit microtears, which leads to plantar fasciopathy. Ultrasound shear wave elastography is an imaging technique to measure shear wave velocity propagating through biological tissues, considered herein as an index of tensile stress. This study aimed to quantify the effect of toe dorsiflexion on the regional distribution of plantar fascia shear wave velocity. METHODS: Shear wave velocity of the plantar fascia was measured in the insertional and distal regions using ultrasound shear wave elastography in sixteen healthy participants (7 males and 9 females). The measurements were performed while the toes were maintained in neutral or dorsiflexed positions. FINDINGS: When considering the insertional region, there was no significant difference in shear wave velocity between neutral toe position [mean (SEM): 5.4 (0.6) m/s] and dorsiflexed toe position [5.5 (0.5) m/s] (P = 0.88; effect size = 0.05). When considering the distal region, there was a significant difference in shear wave velocity between the neutral position [7.8 (0.4) m/s] and dorsiflexed position [9.9 (0.3) m/s] (P = 0.002; effect size = 0.88). The difference in shear wave velocity between the insertional and distal regions showed a large effect size for either neutral (P = 0.010; effect size = 0.75) or dorsiflexed toe position (P = 0.003; effect size = 0.86). INTERPRETATION: In contrast to clinical beliefs, these findings suggest that toe dorsiflexion induces non-homogeneous changes in tensile stress within the plantar fascia.
BACKGROUND: The plantar fascia is exposed to repetitive tensile stress induced by cyclic loads associated with daily activities, such as walking and running. Due to overuse or abnormal foot alignment, insertional and distal (i.e., mid-substance) regions within the plantar fascia may exhibit microtears, which leads to plantar fasciopathy. Ultrasound shear wave elastography is an imaging technique to measure shear wave velocity propagating through biological tissues, considered herein as an index of tensile stress. This study aimed to quantify the effect of toe dorsiflexion on the regional distribution of plantar fascia shear wave velocity. METHODS: Shear wave velocity of the plantar fascia was measured in the insertional and distal regions using ultrasound shear wave elastography in sixteen healthy participants (7 males and 9 females). The measurements were performed while the toes were maintained in neutral or dorsiflexed positions. FINDINGS: When considering the insertional region, there was no significant difference in shear wave velocity between neutral toe position [mean (SEM): 5.4 (0.6) m/s] and dorsiflexed toe position [5.5 (0.5) m/s] (P = 0.88; effect size = 0.05). When considering the distal region, there was a significant difference in shear wave velocity between the neutral position [7.8 (0.4) m/s] and dorsiflexed position [9.9 (0.3) m/s] (P = 0.002; effect size = 0.88). The difference in shear wave velocity between the insertional and distal regions showed a large effect size for either neutral (P = 0.010; effect size = 0.75) or dorsiflexed toe position (P = 0.003; effect size = 0.86). INTERPRETATION: In contrast to clinical beliefs, these findings suggest that toe dorsiflexion induces non-homogeneous changes in tensile stress within the plantar fascia.
Authors: Daniel Baur; Christoph Schwabl; Christian Kremser; Mihra S Taljanovic; Gerlig Widmann; Luca Maria Sconfienza; Judith Sztankay; Gudrun Feuchtner; Andrea S Klauser Journal: J Clin Med Date: 2021-05-27 Impact factor: 4.241