Anatomy and Biomechanics of the First Ray

Glasoe, Ward M.; Yack, H. John; Saltzman, Charles L.

doi:10.1093/ptj/79.9.854

Cited by 77 publications

(61 citation statements)

References 32 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In addition, the mechanical advantage of peroneus longus is reduced in a pronated foot, limiting its ability to stabilize the hallux during the propulsive phase of gait (Donatelli et al, ; Tiberio et al, ). The result is hypermobility of the first ray (Glascoe et al, ), which reduces the effectiveness of the foot as a propulsive lever (Donatelli et al, ).…”

Section: Discussionmentioning

confidence: 99%

Midtarsal break variation in modern humans: Functional causes, skeletal correlates, and paleontological implications

DeSilva

Bonne-Annee

Swanson

et al. 2015

American J Phys Anthropol

View full text Add to dashboard Cite

The midtarsal break was once treated as a dichotomous, non-overlapping trait present in the foot of non-human primates and absent in humans. Recent work indicates that there is considerable variation in human midfoot dorsiflexion, with some overlap with the ape foot. These findings have called into question the uniqueness of the human lateral midfoot, and the use of osteological features in fossil hominins to characterize the midfoot of our extinct ancestors. Here, we present data on plantar pressure and pedal mechanics in a large sample of adults and children (n = 671) to test functional hypotheses concerning variation in midfoot flexibility. Lateral midfoot peak plantar pressure correlates with both sagittal plane flexion at the lateral tarsometatarsal joint, and dorsiflexion at the hallucal metatarsophalangeal joint. The latter finding suggests that midfoot laxity may compromise hallucal propulsion. Multiple regression statistics indicate that a low arch and pronation of the foot explain 40% of variation in midfoot peak plantar pressure, independent of age and BMI. MRI scans on a small subset of study participants (n = 19) reveals that curvature of the base of the 4th metatarsal correlates with lateral midfoot plantar pressure and that specific anatomies of foot bones do indeed reflect relative midfoot flexibility. However, while the shape of the base of the 4th metatarsal may reliably reflect midfoot mobility in individual hominins, given the wide range of overlapping variation in midfoot flexibility in both apes and humans, we caution against generalizing foot function in extinct hominin species until larger fossils samples are available.

show abstract

Section: Discussionmentioning

confidence: 99%

Midtarsal break variation in modern humans: Functional causes, skeletal correlates, and paleontological implications

DeSilva

Bonne-Annee

Swanson

et al. 2015

American J Phys Anthropol

View full text Add to dashboard Cite

show abstract

“…1,2,3 During normal gait at the end of stance the first ray, especially the hallux obtains the highest loads of the foot. 4 Jacob et al reported that 29% of the body weight is acting under the first metatarsal head, and 24% is acting under the big toe. 5 Recent studies suggested that forefoot kinematics are altered by morphologic changes associated with hallux valgus deformity.…”

mentioning

confidence: 99%

Plantar pressure characteristics in hallux valgus feet

et al. 2014

View full text Add to dashboard Cite

Due to the pathoanatomical changes in hallux valgus feet, the plantar flexion moment of the first metatarsophalangeal joint is reduced. Therefore, load bearing of the hallux is decreased during push-off. We assessed loading parameters in hallux valgus feet. Based on dorsal-plantar weight bearing radiographs of 61 feet, the intermetatarsal-, hallux valgus-, distal metatarsal articulationangle, and sesamoid position were evaluated. Plantar pressure assessment was performed with the emed 1 system during level walking. We found negative correlations between hallux valgus angle and peak pressure in the great toe (r ¼ À0.301, p < 0.023), the maximum force of the hallux (r ¼ À0.481, p < 0.001), and contact time of the great toe (r ¼ À0.448, p < 0.001), and positive correlations for force time integral (r ¼ 0.348, p < 0.001), contact area (r ¼ 0.307, p < 0.020), maximum force (r ¼ 0.430, p < 0.001), and peak pressure (r ¼ 0.361, p < 0.006) of the fifth metatarsal head. A positive correlation between the sesamoid and the metatarsal subluxation regarding maximum force (r ¼ 0.294, p < 0.034), and a negative correlation between the contact area of the hallux (r ¼ À0.232, p < 0.020) was shown. Depending on the severity, hallux valgus angle, and sesamoid subluxation, load shows significant lateral transmission in hallux valgus feet. Hallux valgus is a common pathologic, gradually progressive condition of the musculoskeletal system. Due to the weakness of the medial collateral ligament and capsule, the proximal phalanx drifts into valgus, and the metatarsal head drifts into varus. With increasing deviation of the first metatarsal, the medial sesamoid shifts under the metatarsal head, and the lateral sesamoid shifts into the space between the first and the second metatarsal head. As a consequence, the tendons of the extensor hallucis longus and the flexor hallucis longus are shifted laterally, becoming abductors and thereby exacerbating the deformity.

show abstract

“…The medial arch is the chief load-bearing structure in the foot and clinically the most important of the three arches of the foot [10]. NH is proportional to the height of the arch and this makes the navicular bone a suitable reference point in examinations of arch deformities [24].…”

Section: Discussionmentioning

confidence: 99%