A Custom-Made Electronic Dynamometer for Evaluation of Peak Ankle Torque after COVID-19.

The negative effects of SARS-CoV-2 infection on the musculoskeletal system include symptoms of fatigue and sarcopenia. The aim of this study is to assess the impact of COVID-19 on foot muscle strength and evaluate the reproducibility of peak ankle torque measurements in time by using a custom-made electronic dynamometer. In this observational cohort study, we compare two groups of four participants, one exposed to COVID-19 throughout measurements and one unexposed. Peak ankle torque was measured using a portable custom-made electronic dynamometer. Ankle plantar flexor and dorsiflexor muscle strength was captured for both feet at different ankle angles prior and post COVID-19. Average peak torque demonstrated no significant statistical differences between initial and final moment for both groups (p = 0.945). An increase of 4.8%, p = 0.746 was obtained in the group with COVID-19 and a decrease of 1.3%, p = 0.953 was obtained in the group without COVID-19. Multivariate analysis demonstrated no significant differences between the two groups (p = 0.797). There was a very good test−retest reproducibility between the measurements in initial and final moments (ICC = 0.78, p < 0.001). In conclusion, peak torque variability is similar in both COVID-19 and non-COVID-19 groups and the custom-made electronic dynamometer is a reproducible method for repetitive ankle peak torque measurements.

A Custom-Made Lower Limb Dynamometer for Assessing Ankle Joint Torque in Humans: Calibration and Measurement Procedures.

Custom-made dynamometry was shown to objectively analyze human muscle strength around the ankle joint with accuracy, easy portability and low costs. This paper describes the full method of calibration and measurement setup and the measurement procedure when capturing ankle torque for establishing reliability of a portable custom-built electronic dynamometer. After considering the load cell offset voltage, the pivotal position was determined, and calibration with loads followed. Linear regression was used for calculating the proportionality constant between torque and measured voltage. Digital means were used for data collection and processing. Four healthy consenting participants were enrolled in the study. Three consecutive maximum voluntary isometric contractions of five seconds each were registered for both feet during plantar flexion/dorsiflexion, and ankle torque was then calculated for three ankle inclinations. A calibration procedure resulted, comprising determination of the pivotal axis and pedal constant. Using the obtained data, a measurement procedure was proposed. Obtained contraction time graphs led to easier filtering of the results. When calculating the interclass correlation, the portable apparatus demonstrated to be reliable when measuring ankle torque. When a custom-made dynamometer was used for capturing ankle torque, accuracy of the method was assured by a rigorous calibration and measurement protocol elaboration.

Surgical treatment in a case of giant macrodystrophia lipomatosa of the forefoot.

Macrodystrophia lipomatosa is a rare, congenital, non-hereditary disease, characterized by local gigantism of the fingers or toes. We report the case of a 37-month-old boy, with no prior past medical history, who presented with a gigantic dystrophy of the left forefoot. The location of the deformity was involving the plantar and dorsal aspect of the foot, and digits 1 to 4. After clinical examination, imaging study assessment, and differential diagnosis considerations, it was established that macrodystrophia lipomatosa was the cause of the deformity. A reconstructive surgical intervention was planned. The hypertrophied tissues were excised, resulting in a reduction in the forefoot's volume. The patient had a favorable postoperative course and ambulation was allowed with a custom-made shoe. The case represents a rare pathological entity with complex diagnostic and therapeutic considerations. As far as treatment options, the surgeon must decide between a reconstructive surgical intervention and amputation.

Morphological and functional characterization of femoral head drilling-derived mesenchymal stem cells.

Adult mesenchymal stem cells (MSCs) were primary identified as bone marrow-derived cells, fibroblast-like morphology, and adherent to plastic surfaces of in vitro culture plate. Their identification criteria evolved in time to a well-established panel of markers (expression of CD73, CD90, and CD105) and functional characteristics (adipogenic, osteogenic, and chondrogenic trilineage differentiation ability), which can be applied to adult mesenchymal stem cells obtained from other tissue sources. We tried to assess the potential stemness of femoral head drilling-derived cells as a new source of mesenchymal stem cells (FH-MSCs). For this purpose, we used the morphological and ultrastructural characteristics defined by scanning and transmission electron microscopy and spindle-shape cellular body, fibroblast-like, with few thick elongations (lamellipodia) and numerous fine, thin cytoplasmic projections (filopodia) that extend beyond the edge of lamellipodia. Immunophenotypical analysis was performed by flow cytometry and immunocytochemical methods and we showed that FH-MSCs share the characteristic markers of MSCs, expressing CD73, CD90, CD105, and being positive for vimentin, and c-kit (CD117). Proliferation rate of these cells was moderate, as revealed by Ki67 immunostaining. Regarding the functional characteristics of FH-MSCs, after appropriate time of induction in specific culture media, the cells were able to prove their trilineage potential and differentiated towards adipocytic, osteogenic, and chondrogenic lineage, as revealed by immunofluorescent staining. We may conclude that femoral head drilling-derived cells can be used as a novel source of stem cells, and employed in diverse clinical settings.