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Examination of Foot and Ankle in a Child
Published in Nirmal Raj Gopinathan, Clinical Orthopedic Examination of a Child, 2021
Nirmal Raj Gopinathan, Mandeep Singh Dhillon, Pratik M. Rathod
The child is asked to stand with both feet identically placed, and the examiner inspects them from the back to look for heel alignment with the rest of the leg and ankle, which may be neutral, valgus, or varus. The midsagittal axis of the calcaneus is normally lateral to the midsagittal axis of the talus and tibia, and the foot is in slight valgus alignment3. (Figure 11.9) (valgus is the heel directed away from the midline, and varus is the heel directed toward the midline). Usually, the varus and valgus pertain to the subtalar joint; in rare circumstances, the valgus or varus might be due to ankle conditions like physeal arrest. Also, note the relation of the foot to the ankle, whether it is in equinus or calcaneus, in the sagittal plane.
Biomechanics of the foot and ankle
Published in Maneesh Bhatia, Essentials of Foot and Ankle Surgery, 2021
Sheraz S Malik, Shahbaz S Malik
A static analysis with a free-body diagram can be used to estimate the loads acting at the ankle joint when a person stands on the tiptoes on one leg (Figure 3.4). This is an example of a class two lever system, with three coplanar forces acting on the foot:Ground reaction force (Force W) – It is acting at the metatarsal heads, directed vertically upward and its magnitude is equal to body weight, W.Muscle force through Achilles tendon (Force A) – This is acting at the point where tendon is inserted onto calcaneus,7 taken to act vertically upward (although if the knee is flexed, it would be acting at an angle from vertical), and its magnitude is unknown. Due to its extension posterior to the ankle joint, the calcaneus acts as a lever arm for Achilles tendon, so that it acts at a short distance from centre of rotation of the ankle joint.Joint reaction force (Force J) – This is the reaction (contact) force of tibia on the talar dome. It is taken to act vertically downward and its magnitude is unknown.
Osteoporotic os calcis fractures
Published in Peter V. Giannoudis, Thomas A. Einhorn, Surgical and Medical Treatment of Osteoporosis, 2020
Angus Jennings, Richard Buckley
The calcaneus has become an important peripheral site for osteoporosis assessment (6). Significant efforts have been made to investigate the microarchitecture of the calcaneus, but much less work has focused on its function. There is little clinical evidence as to how either form or function, alone or in combination, contribute to the occurrence of calcaneal fractures.
Modelling the complexity of the foot and ankle during human locomotion: the development and validation of a multi-segment foot model using biplanar videoradiography
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2022
Jayishni N. Maharaj, Michael J. Rainbow, Andrew G. Cresswell, Sarah Kessler, Nicolai Konow, Dominic Gehring, Glen A. Lichtwark
We aligned the coordinate system of each rigid body such that when the model is in the anatomical position, the x-direction pointed anteriorly, the y-direction pointed superiorly and the z-direction to the right. The talus coordinate system was located at the midpoint between the medial and lateral malleoli markers, at vertical centre of the bone. The calcaneus coordinate system was located at the midpoint between the medial and lateral calcaneal markers, at vertical centre of the bone. The midfoot coordinate system was located at the midpoint between the navicular and fifth metatarsal base at the proximal aspect of the segment. The forefoot coordinate system was located at the second metatarsal base while the coordinate systems for the digits was located at the second proximal phalanx.
A simple and effective 1D-element discrete-based method for computational bone remodeling
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2022
Diego Quexada-Rodríguez, Kalenia Márquez-Flórez, Miguel Cerrolaza, Carlos Duque-Daza, Olfa Trabelsi, M.A Velasco, Salah Ramtani, Marie Christine Ho-Ba-Tho, Diego Garzón-Alvarado
The calcaneus bone is the largest tarsal bone and it is characterized by a cortex containing trabecular bone (Metcalf et al. 2018). Due to the mechanical stresses acting on the calcaneus, a set of trabecular groups are formed and play a crucial role in the biomechanics of this bone. These are important in orthopedic procedures and pathology treatments that compromise bone integrity such as in osteoarthritis therapy. The loading conditions were addressed as bone remodeling problems with the methodology proposed herein. The resulting trabecular groups resemble those seen in the calcaneus bone illustrated in Figure 16(c). As in the previous medical case, a set of main trabecular groups have been identified as displayed in Figure 16(b). These are in good agreement with anatomical studies regarding the biomechanics of calcaneus bone (Abboud 2018). The following trabecular motifs can be identified individually for the boundary conditions of (Belinha et al. 2012): thalamic group (1); inferior plantar group (2); anterior apophyseal group (3); anterior plantar group (4); posterior achillean group (5); and central triangular area of refracted bone (6). An aspect that calls attention in some of these groups is the appearance of single lines corresponding to long trabecular groups such as the anterior apophyseal group or the central triangular area of refracted bone; this “thinning” could mean that the particular group does not play a vital structural role for that specific case load.
Mycobacterium abscessus felon complicated with osteomyelitis: not an ordinary nail salon visit
Published in Acta Clinica Belgica, 2020
Jose Armando Gonzales Zamora, Abelardo Villar Astete
Osteomyelitis secondary to M. abscessus is very rare and occurs usually after a penetrating trauma. Cases of foot osteomyelitis by M. abscessus after a flat foot reconstruction and following a plantar puncture wound have been reported [4,18]. Another interesting case was described by Yen-Chun et al., who reported a case of calcaneus osteomyelitis that resembled a tumor [19]. Interestingly, no history of trauma was endorsed by the affected patient. Other areas involved in cases of osteomyelitis have been the lumbar spine, and the mandible [20,21]. In the latter, osteomyelitis was associated with pulpotomy procedures and root canal treatments [21,22]. To our knowledge, no cases of osteomyelitis following manicures or pedicures have been reported in the literature to date.