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Biomechanics of the foot and ankle
Published in Maneesh Bhatia, Essentials of Foot and Ankle Surgery, 2021
Sheraz S Malik, Shahbaz S Malik
The normal external torsion of distal tibia (and fibula) in relation to tibial plateau means that the ankle joint axis is externally rotated 20–25° in relation to the knee joint axis, although the foot is slightly internally rotated in relation to the ankle. The more posterior position of lateral malleolus is also a result of external tibial torsion.3 The joint axis is laterally tilted 14° in the coronal plane, and 6° in the transverse plane (Figure 3.3). Inman4 described the axis as passing just distal to medial and lateral malleoli. The joint movements mostly consist of dorsiflexion and plantarflexion. The normal range of motion of ankle is 10–20° of dorsiflexion and 25–30° plantarflexion, but usually only 10° of dorsiflexion and 20° of plantarflexion is required for normal locomotion. The varus tilt of the axis causes the talus to also rotate in the coronal plane, with dorsiflexion producing external rotation up to 10° and plantarflexion producing internal rotation up to 7°. Thus, dorsiflexion results in a lateral forefoot position and plantarflexion leads to medial forefoot position. When the foot is planted on the ground, dorsiflexion causes internal rotation of tibia and plantarflexion produces external rotation of tibia.
Paediatric Orthopaedic Surgery
Published in Timothy W R Briggs, Jonathan Miles, William Aston, Heledd Havard, Daud TS Chou, Operative Orthopaedics, 2020
Jonathan Wright, Russell Hawkins, Aresh Hashemi-Nejad, Peter Calder
Equinus: With the hindfoot varus corrected, serial casts are applied in a progressively dorsiflexed position. This usually requires two to three casts to achieve 15° of dorsiflexion and 60° of external rotation. Dorsiflexion is achieved via pressure beneath the midfoot rather than the metatarsals to avoid rocker-bottom feet.
The Mechanics of Gait
Published in Verna Wright, Eric L. Radin, Mechanics of Human Joints, 2020
Dorsiflexion of the ankle is accomplished by three muscles: tibialis anterior, extensor hallucis longus, and extensordigitorum longus (Fig. 7). Their periods of action are very similar. Activity begins in preswing just before toe-off and continues through the three phases of swing and loading response.
Spinal arachnoiditis leading to recurrent reversible myelopathy: A case report
Published in The Journal of Spinal Cord Medicine, 2022
Erol Jahja, Charles Sansur, Peter Howard Gorman
We present a 65-year-old male with American Spinal Injury Association impairment scale (AIS) D paraplegia secondary to a GSW in 1972 with retained paraspinal bullet fragments at T12 and L1. At the time of the GSW, the patient underwent exploratory surgery including a two-level lumbar laminectomy, but the major bullet fragments could not be removed. The patient experienced transient paraplegia at the time of the GSW. He underwent multiple myelograms with unknown dye material during the first few years after injury. He also reported that during those early post-injury years he was treated for infections related to the GSW. Nonetheless, the patient had been able to ambulate independently using a cane and maintained bowel and bladder continence over subsequent decades. At baseline (the year 2015) the patient had left foot dorsiflexion weakness (grade 4 out of 5 on manual muscle testing) along with chronic nociceptive and neuropathic back pain which were well managed on stable dosages of neuropathic and narcotic analgesics. It should also be noted that the bullet fragment adjacent to the spinal column was noted to be in the same anatomical position over multiple images obtained over different years.
Isolating the Superficial Peroneal Nerve Motor Branch to the Peroneus Longus Muscle with Concentric Stimulation during Diagnostic Motor Nerve Biopsy
Published in The Neurodiagnostic Journal, 2022
Ashley Rosenberg, Rachel Pruitt, Sami Saba, Justin W. Silverstein, Randy S. D’Amico
Arising from the sciatic nerve, the CPN travels in the posterior thigh to cross the lateral head of the gastrocnemius muscle to enter the anterolateral portion of the leg just below the fibular head. Here, the CPN divides into articular, deep, and superficial divisions (Figure 3A). The articular division innervates the joint capsule. The DPN innervates the anterior leg muscles responsible for dorsiflexion and terminates in a cutaneous branch between the first and second toe. The SPN provides motor innervation to the peroneus longus and the peroneus brevis only. Otherwise, the SPN provides cutaneous innervation to the lateral leg below the knee (D’Amico and Winfree 2017). The peroneus longus and peroneus brevis are located in the lateral portion of the leg and function primarily to evert the ankle, with the peroneus brevis considered more effective as an evertor than the peroneus longus (Lee et al. 2011). Both muscles also function in conjunction with the tibialis posterior in plantar flexion of the foot at the ankle (D’Amico and Winfree 2017).
Kinematic and Temporospatial Changes in Children with Cerebral Palsy during the Initial Stages of Gait Development
Published in Developmental Neurorehabilitation, 2022
Rigas Dimakopoulos, George Syrogiannopoulos, Ioanna Grivea, Zoe Dailiana, Sotirios Youroukos, Arietta Spinou
Regarding the differences in ankle kinematics between children with bilateral CP and TD children, we recorded a significant lower maximum ankle dorsiflexion during the stance phase in children with bilateral CP compared to TD children at baseline. In children with bilateral CP, it seems as the movement of the ankle is limited around the ‘middle range’ of the joint throughout the walking cycle (Figure 1). In the stance phase, this could be attributed to the hyperactivity of the spastic triceps surae muscles, which does not allow efficient forward movement of the tibia over the talus.21 Additionally, the reduction of the dorsiflexion in children with bilateral CP in stance phase results in the decrease of the total ankle range of movement, thus the joint stiffness increases. This could constitute an adaptive response during the initial stages of gait development that allows children to store elastic energy and establish a more efficient walking pattern, with the least possible energy consumption.22–24 In contrast, it is possible that the excessive dorsiflexion may even have negative effects on the walking ability of children with bilateral CP.9