First Metatarsophalangeal Angle Research Articles

Foot-Healthcare Application Using Inertial Sensor: Estimating First Metatarsophalangeal Angle From Foot Motion During Walking

Our purpose was to demonstrate the possibility of providing foot-healthcare application by using an in-shoe motion sensor (IMS) through validating the feasibility of applying an IMS for measuring the first metatarsophalangeal angle (FMTPA), which is the most important parameter regarding the common foot problem hallux valgus. Methods: The IMS signals can represent foot motions when the mid-foot and hindfoot were modelled as a rigid body. FMTPAs can be estimated from the foot-motion signals measured using an IMS embedded beneath the foot arch near the calcaneus side using a machine-learning method. The foot-motion signals were collected from 50 participants with different FMTPAs. The true FMTPAs were assessed from digital photography. Correlation-based feature-selection processes (significance level <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${p} &lt; 0.05$ </tex-math></inline-formula> ) were used to search for the predictors from the foot-motion signals. Leave-one-subject-out cross-validation, root mean squared error, and intra-class coefficients were used for FMTPA-estimation model evaluation. Results: Eleven FMTPA-impacted gait-phase clusters, which were used to construct effective foot-motion predictors, were observed in all gait-cycle periods except terminal swing. The range of the foot motion in the sagittal and coronal planes significantly correlated with the FMTPA ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${p} &lt; 0.05$ </tex-math></inline-formula> ). Linear regression could be the best method for constructing an FMTPA estimation model with a root mean squared error and intra-class correlation coefficient of 4.2 degrees and 0.789, respectively. Conclusion: The results indicate the reliability of our FMTPA estimation model constructed from foot-motion signals and the possibility to providing foot-healthcare applications by using an IMS.

The thickness of heel fat-pad in patients with plantar fasciitis

ObjectiveThe aim of this study was to investigate the thickness of heel fat pad (THP) and to detect the relationship between the plantar fasciitis (PF) and age, occupation, BMI, longitudinal arch, the thickness of heel fat-pad in the patients with PF. MethodsA total of 50 patients (29 women and 21 men; mean age: 46.5 years (range: 22–70)) that were diagnosed with PF were included to this study. Patients' affected side were compared with the healthy opposite side with the angle of medial arch (AMA) and first metatarsophalangeal angle (FMTPA) on the foot radiograms, and THP and thickness of first metatarsal fat pad (TFMFP) using ultrasonography (USG) of both feet. ResultsThe mean AMAs of feet with pain and without pain were 122.56° and 120.60°, respectively. The mean FMTPAs of feet with pain and without pain were 14.72° and 14.40°, respectively. The mean THPs of feet with pain at the point of the medial calcaneal tubercle and the mean TFMFPs of the feet with pain at the point of the first metatarsal head were 19.45 mm and 6.75 mm, respectively. The mean THPs of feet without pain at the point of the medial calcaneal tubercle and the mean TFMFPs of the feet without pain at the point of the first metatarsal head were 19.94 mm and 6.75 mm, respectively. It was observed that the mean AMA in the heels with pain was significantly higher than that of the heel without pain (p < 0.05) and the mean THP in the heels with pain was significantly thinner than that of the heel without pain (p < 0.05). ConclusionThe results indicate that USG is an accurate and reliable imaging technique for the measurement of THP in the diagnosis of plantar fasciitis and the heel pad was thinner in the painful heels of patients with plantar fasciitis. Level of evidenceLevel III, Diagnostic Study.

The “Scarf” Osteotomy for the Correction of Hallux Valgus

Correction of symptomatic valgus deformities. A hallux valgus in which the pathologic intermetatarsal angle I–II can be fully corrected by a lateral shift of the metatarsal head not exceeding two thirds of its width. Hypermobility of the first ray. Osteoporosis. Osteoarthritis of the first metatarsophalangeal joint. Medial longitudinal incision extending from the first metatarsophalangeal joint to the midportion of the metatarsal. Tenotomy of the abductor hallucis longus tendon, and lateral longitudinal incision of the metatarsophalangeal joint capsule to allow complete repositioning of the metatarsal head over the sesamoid bones. Z-shaped osteotomy in the mediolateral plane of the distal two thirds of the first metatarsal. Lateral shift of the distal fragment to reduce the intermetatarsal angle to a physiologic one. A pathologic distal metatarsal articular angle can be corrected simultaneously by rotating the distal fragment medially. Medial metatarsophalangeal capsulorrhaphy. Between October 1995 and July 1998, 73 Scarf osteotomies were performed in 57 patients and followed up clinically and radiologically for an average of 23 (12–45) months. The average intermetatarsal angle I–II was reduced from 12° to 6° and the first metatarsophalangeal angle from 27° to 11°. Patient’s satisfaction assessed in a visual 0–10 analog scale (10 points representing complete satisfaction) reached a mean value of 9.2 points. Three patients would not undergo the operation again (one bilateral severe undercorrection, one painful osteoarthritis of the first metatarsophalangeal joint, and one overcorrection).