BACKGROUND: Plantar soft tissue stiffness and thickness are important biomechanical variables to understand stress concentrations that may contribute to tissue injury. OBJECTIVE: The purpose of this study was to determine the effects of passive metatarsal phalangeal joint (MPJ) extension on plantar soft tissue stiffness and thickness. METHODS: Seventeen healthy participants (7 male, 10 female, mean age 25.3 years, S.D. 4.4 years, mean BMI 24.7 kg/m(2), S.D. 3.2 kg/m(2)) were tested. Plantar soft tissue stiffness and thickness were measured at the metatarsal heads, midfoot and heel using a custom-built indentor device and an ultrasound machine. RESULTS: Indicators of soft tissue stiffness (K1 values) at the metatarsal heads and midfoot showed increases in stiffness of 81-88% (S.D.20-33%) in the MPJ extension position compared with the MPJ neutral position. Soft tissue thickness measures at the metatarsal heads with the MPJ in neutral ranged from a mean of 8.9 to 13.5mm and decreased, on average, by 8.8% (S.D. 2.9%) with MPJ extension. CONCLUSIONS: MPJ extension has a profound effect on increasing forefoot plantar soft tissue stiffness and a consistent but minimal effect on reducing soft tissue thickness. These changes may help transform the foot into a rigid lever at push-off consistent with the theory of the windlass mechanism.
BACKGROUND: Plantar soft tissue stiffness and thickness are important biomechanical variables to understand stress concentrations that may contribute to tissue injury. OBJECTIVE: The purpose of this study was to determine the effects of passive metatarsal phalangeal joint (MPJ) extension on plantar soft tissue stiffness and thickness. METHODS: Seventeen healthy participants (7 male, 10 female, mean age 25.3 years, S.D. 4.4 years, mean BMI 24.7 kg/m(2), S.D. 3.2 kg/m(2)) were tested. Plantar soft tissue stiffness and thickness were measured at the metatarsal heads, midfoot and heel using a custom-built indentor device and an ultrasound machine. RESULTS: Indicators of soft tissue stiffness (K1 values) at the metatarsal heads and midfoot showed increases in stiffness of 81-88% (S.D.20-33%) in the MPJ extension position compared with the MPJ neutral position. Soft tissue thickness measures at the metatarsal heads with the MPJ in neutral ranged from a mean of 8.9 to 13.5mm and decreased, on average, by 8.8% (S.D. 2.9%) with MPJ extension. CONCLUSIONS: MPJ extension has a profound effect on increasing forefoot plantar soft tissue stiffness and a consistent but minimal effect on reducing soft tissue thickness. These changes may help transform the foot into a rigid lever at push-off consistent with the theory of the windlass mechanism.
Authors: Joseph W Klaesner; Mary K Hastings; Dequan Zou; Cara Lewis; Michael J Mueller Journal: Arch Phys Med Rehabil Date: 2002-12 Impact factor: 3.966
Authors: Alexandria Kappel-Bargas; Richard D Woolf; Mark W Cornwall; Thomas G McPoil Journal: Clin Biomech (Bristol, Avon) Date: 1998-04 Impact factor: 2.063
Authors: Ahmet Erdemir; Jeffrey J Saucerman; David Lemmon; Bryan Loppnow; Brie Turso; Jan S Ulbrecht; Peter Re Cavanagh Journal: J Biomech Date: 2005-09 Impact factor: 2.712
Authors: Michael J Mueller; Mary Hastings; Paul K Commean; Kirk E Smith; Thomas K Pilgram; Douglas Robertson; Jeffrey Johnson Journal: J Biomech Date: 2003-07 Impact factor: 2.712
Authors: Judith R Gelber; David R Sinacore; Michael J Strube; Michael J Mueller; Jeffrey E Johnson; Fred W Prior; Mary K Hastings Journal: Foot Ankle Int Date: 2014-06-10 Impact factor: 2.827
Authors: Victoria Spartacus; Maedeh Shojaeizadeh; Vincent Raffault; James Shoults; Ken Van Wieren; Carolyn J Sparrey Journal: PLoS One Date: 2021-12-13 Impact factor: 3.240