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The Mechanics of Gait
Published in Verna Wright, Eric L. Radin, Mechanics of Human Joints, 2020
Control of the subtalar and midtarsal joints is provided by the same muscles, as all the insertions are distal to both joints. The primary inversion force is the tibialis posterior. This muscle is active through the weight-bearing period, with peaks during loading response and terminal stance (Fig. 6). Medial footsupport is also assisted by the long toe flexors (flexor hallucis longus and flexor digitorum longus) and the plantar intrinsic muscles.
Contribution of the tibialis posterior and peroneus longus to inter-segment coordination of the foot during single-leg drop jump
Published in Sports Biomechanics, 2020
Hiroshi Akuzawa, Atsushi Imai, Satoshi Iizuka, Naoto Matsunaga, Koji Kaneoka
Coordinated motions of the foot segments are controlled by a variety of structures. The long and short plantar ligaments, spring ligament and plantar fascia are fundamental passive structures that support the foot segments and arches (Iaquinto & Wayne, 2010; Mengiardi et al., 2016). Sensory receptors are abundantly distributed within these passive structures (McKeon et al., 2015). The afferent information from sensory receptors leads to muscle activation to achieve proper joint stability for a specific functional demand (Panjabi, 1992). The muscles interact with these passive structures and sensory receptors to support the segments in the mid-range, whereas ligaments or other passive structures contribute less to joint stability (Cholewicki et al., 1997; McKeon et al., 2015). The extrinsic muscles for the foot, such as the tibialis posterior (TP), peroneus longus (PL), and flexor digitorum longus (FDL), play an important role in controlling the foot kinematics. The TP and FDL muscles support the medial longitudinal arch of the foot (Hofmann et al., 2013; Kamiya et al., 2012; Semple et al., 2009). The TP dysfunction leads to flatfoot deformity (Smyth et al., 2017). The PL functions to stabilise the transverse arch of the foot (Johnson & Christensen, 1999). In a sufficiently stabilised foot condition, the propulsion force produced by the gastrocnemius (GS) muscle can be efficiently transmitted to the ground. Therefore, the interaction of these extrinsic muscles can control the complex foot segments.
Characteristics of lower leg and foot muscle thicknesses in sprinters: Does greater foot muscles contribute to sprint performance?
Published in European Journal of Sport Science, 2019
Takahiro Tanaka, Tadashi Suga, Yuya Imai, Hiromasa Ueno, Jun Misaki, Yuto Miyake, Mitsuo Otsuka, Akinori Nagano, Tadao Isaka
The measured foot muscles were as follows: flexor digitorum longus (FDL), flexor hallucis longus (FHL), peroneal longus and brevis (PLB), abductor hallucis (AbH), flexor digitorum brevis (FDB), and flexor hallucis brevis (FHB). Thicknesses of these foot muscles were measured based on the method used in previous studies (Angin et al., 2014; Crofts et al., 2014; Mickle et al., 2013). Briefly, thicknesses of the FDL and FHL were measured at 50% of the distance from the medial tibial plateau to the inferior border of the medial malleolus. Thickness of the PLB was measured at 50% of the distance from the fibular head to the inferior border of the lateral malleolus. Thickness of the AbH was measured at a section of muscle belly along an axial line between the medial malleolus tuberosity of the tibia and navicular tuberosity. Thickness of the FDB was measured at a section along a longitudinal line from the medial tubercle of the calcaneus to the third toe. Thickness of the FHB was measured at the section along a transverse line drawn at 50% of the distance between the medial tibial plateau and inferior border of the medial malleolus on the posterior aspect of the tibia.
Tibialis posterior muscle activity alteration with foot orthosis insertion measured by fine-wire electromyography
Published in Footwear Science, 2021
Hiroshi Akuzawa, Atsushi Imai, Satoshi Iizuka, Naoto Matsunaga, Koji Kaneoka
Human beings have a unique foot structure because they are the only mammals that can walk in an upright posture on two legs. Adapting to bipedal walking, the shape and function of the foot have evolved. The human foot has alterable flexibility and rigidity, absorbs impact, and effectively transmits propulsion forces during gait (Kokubo et al., 2012). Absorbing impact and transmitting propulsion forces require opposite properties, and these conflicting features are controlled by complex components of the foot, including ligaments, tendons, joint alignment, and muscles (Blackwood et al., 2005; Kokubo et al., 2012; McKeon et al., 2015). Calf muscles play an important role in altering foot properties because muscles are the only structures that can actively control the alignment. The tibialis posterior (TP), flexor digitorum longus (FDL), and peroneus longus (PL) are fundamental muscles that significantly control the rigidity and flexibility of the foot (Hofmann et al., 2013; Kokubo et al., 2012; Murley, Buldt, et al., 2009). The TP is the strongest foot invertor muscle that inverts the rearfoot, resulting in increased foot rigidity (Blackwood et al., 2005; Semple et al., 2009). On the lateral side of the foot, the PL produces eversion of the subtalar joint (Klein et al., 1996). Contraction of the PL during weight-bearing conditions leads to a decrease in foot rigidity and an increase in the energy dissipation rate (Kokubo et al., 2012). The FDL shows isometric contraction during the stance phase of gait and maintains the longitudinal arch while conserving the propulsion force (Hofmann et al., 2013). The combined functions of these muscles satisfy the complex demands of the foot. However, the activity of these muscles during running is unclear, as much research has been done only on walking.