Associations Between the Size of Individual Plantar Intrinsic and Extrinsic Foot Muscles and Toe Flexor Strength

Background The size of the plantar intrinsic and extrinsic foot muscles has been shown to be associated with toe flexor strength (TFS). Previous studies adopted the size of a limited plantar intrinsic foot muscle or a compartment containing several muscles as an independent variable for TFS. Among the plantar intrinsic and extrinsic foot muscles, therefore, it is unclear which muscle(s) primarily contributes to TFS development. The present study aimed to clarify this subject. Methods In 17 young adult men, a series of anatomical cross-sectional area of individual plantar intrinsic and extrinsic foot muscles was obtained along the foot length and the lower leg length, respectively, using the magnetic resonance imaging. Maximal anatomical cross-sectional area (ACSAmax) and muscle volume (MV) for each constituent muscle of the plantar intrinsic foot muscles (flexor hallucis brevis; flexor digitorum brevis, FDB; abductor hallucis; adductor hallucis oblique head, ADDH-OH; adductor hallucis transverse head, ADDH-TH; abductor digiti minimi; quadratus plantae) and extrinsic foot muscles (flexor hallucis longus; flexor digitorum longus) were measured. TFS was measured with a toe grip dynamometry. Results TFS was significantly associated with the ACSAmax for each of the ADDH-OH (r = 0.674, p = 0.003), ADDH-TH (r = 0.523, p = 0.031), and FDB (r = 0.492, p = 0.045), and the MV of the ADDH-OH (r = 0.582, p = 0.014). As for the ADDH-OH, the correlation coefficient with TFS was not statistically different between ACSAmax and MV (p = 0.189). Stepwise regression analysis indicated that ACSAmax and MV of the ADDH-OH alone explained 42% and 29%, respectively, of the variance in TFS. Conclusion The ADDH-OH is the key muscle that primarily contributes to TFS development among the plantar intrinsic and extrinsic foot muscles.

Morphological characteristics of intrinsic foot muscles among flat foot and normal foot using ultrasonography_

Purpose: The purpose of this study was to compare the morphology of the intrinsic foot muscle between typical foot and flat foot with the use ultrasound. Methods: Thirty-seven healthy participants were recruited in this study. Foot types were classified using the Foot posture index 6-item version. A total of 43 flat feet and 31 typical feet were examined. Using B-mode ultrasound imaging, the morphology of the abductor hallucis, oblique head of adductor hallucis, abductor digiti minimi, and flexor digitorum brevis muscles were measured. Morphology of all muscles measured was normalized by body height. The independent Student’s t-test was used to examine the differences in the thickness and the cross-sectional area (CSA) of the intrinsic foot muscle among the two groups. Results: The thickness of abductor hallucis was significantly larger in flat foot group. The thickness and CSA of abductor digiti minimi and the thickness of oblique head of adductor hallucis were significantly smaller in flat foot group. Conclusions: Our results showed hypertrophied adductor hallucis, atrophied abductor digiti minimi, and atrophied oblique head of the adductor hallucis in individuals with flat feet, suggesting a possible tendency to hypertrophy in muscles that are located in a medial position and a possible tendency to atrophy in muscles that are located in a lateral position in flat feet.

Traumatic Hallux Varus Treated by Minimally Invasive Extensor Hallucis Brevis Tenodesis

A case of traumatic hallux varus due to avulsion fracture of the lateral side of the base of proximal phalanx was reported. The lateral instability of the first metatarsophalangeal joint was believed to be due to the disruption of adductor hallucis function. It was successfully managed by minimally invasive extensor hallucis brevis tenodesis.

THE CORRECTION OF HALLUX VARUS DEFORMITY IN CONSEQUENCE OF SURGICAL TREATMENT FOR HALLUX VALGUS

The analysis of treatment of 21 patients (24 feet) with postoperative hallux varus deformity which have arisen after operations apropos hallux valgus is carried out. For correction of vicious position of the first finger we successfully carried out the Brandes procedure, sometimes in a combination to operations on sinews of muscles of the first finger - an adductor hallucis tendotomy and/or lengthening of the extensor hallucis longus tendon.

The Effect of Adductor Tendon Transposition in the Modified McBride Procedure

The modified McBride technique is widely used in bunion surgery. The aim of this report is to analyze the influence that transferring the adductor hallucis tendon had on the first intermetatarsal angle (IMA), hallux abductus angle (HAA), and tibial sesamoid position (TSP) when used to correct the hallux valgus deformity. A prospective study was conducted of 31 hallux abducto valgus patients. A modified McBride procedure was performed to repair the deformity. In 16 patients (group 1), the adductor tendon was transferred, and in 15 (group 2), it was not. The tendon transfer was at random. The preoperative and postoperative variables IMA, HAA, and TSP were measured and analyzed by means of univariate and multivariate statistics. In group 1, the preoperative values of the first IMA and the HAA averaged 13.5° and 30°, respectively, decreasing postoperatively to 10.3° and 10.7°. In group 2, the corresponding preoperative angles were 12.9° and 25.6°, and the postoperative angles were 9.7° and 10°. There were no statistically significant differences between the 2 groups in the correction of the IMA, HAA, and TSP. As measured by the aforementioned radiographic measurements, there is no advantage in transferring the adductor hallucis tendon to the first metatarsophalangeal joint capsule in the correction of hallux valgus