Effect of Foot Orthoses in Children With Symptomatic Flexible Flatfoot Based on Ultrasonography of the Ankle Invertor and Evertor Muscles

Objective To examine the changes in the cross-sectional area (CSA) ratio of the ankle invertors and evertors following rigid foot orthosis (RFO) application in children with symptomatic flexible flatfoot and to determine the correlation between the degree of change in CSA ratio and pain-severity after RFO application.Methods We included 24 children with symptomatic flexible flatfoot without comorbidities and measured the CSAs of tibialis anterior (TA), tibialis posterior (TP), and peroneus longus (PL) using ultrasonography, resting calcaneal stance position (RCSP) angle, calcaneal pitch (CP), Meary’s angle, talonavicular coverage angle, and talocalcaneal angle using radiography, and foot function index (FFI) at baseline and 12 months after RFO application. We analyzed 48 data by measuring both feet of 24 children. The CSA ratios, the ratio of CSA of each muscle to the sum of CSA of TA, TP, and PL, were also compared. Correlations between the degree of change in FFI, each muscle’s CSA ratio, RCSP angle, and radiographic measurements were investigated.Results Following RFO application, significant increase in the PL ratio and CP and significant decrease in the RCSP angle, FFI total, pain, and disability scores were observed. The degree of change in the total score, pain, and disability score of FFI were significantly correlated with the degree of change in the PL ratio and RCSP angle.Conclusion RFOs applied to children with symptomatic flexible flatfoot might reduce the compensatory activities of the ankle invertors, thereby increasing the PL ratio, and pain decreases as the PL ratio increases.

Histology of Muscle Development in Pigs, Epigenetics from Myotubes to Tapered Fibres

Pre-natal muscle development in pigs starts with myotubes (axial nuclei in a tube of myofibrils) and secondary fibres (peripheral nuclei on an axial strand of myofibrils). By the time of birth, the nuclei of myotubes move to a peripheral position like secondary fibres. As pre-natal secondary fibres grow in length, the number of fibres in a transverse section may appear to increase. This stereology may also occur in post-natal muscles that have tapered fibres anchored in endomysial connective tissue around adjacent fibres and with one or both ends not reaching the end of their fasciculus. Up to 100 days gestation, Peroneus longus (no tapered fibres) had larger (P < 0.001) diameter secondary fibres than Longissimus thoracis (with tapered fibres). Up to 100 days gestation, no radial growth of secondary fibres was detected, but myotubes decreased in diameter (P < 0.001). From a curve showing the relative numbers of myotubes and secondary fibres, it was deduced that approximately 80% of muscle fibres in pigs are derived from secondary fibres. In post-natal Sartorius muscle there was an increase (P < 0.005) in the apparent number of muscle fibres attributed to longitudinal growth of tapered fibres. Myotubes located centrally within their fasciculi had the same position as slow-contracting fibres with a high myoglobin content in adult muscle. Post-natal changes in muscle fibre histochemistry were achieved through transitional types, probably neurally regulated rather than by differential longitudinal growth of tapered endings. Secondary fibres are important – they give rise to both the majority of muscle fibres in adult pigs and affect subsurface optical pathways and pork colourimetry.

Effect of Peroneus Longus Muscle Release on Abductor Hallucis Muscle Activity and Medial Longitudinal Arch before Toe-Tap Exercise in Participants with Flexible Pes Planus

Pes planus is a medical condition of the foot wherein there is a flattening or lowering of the medial longitudinal arch. The abductor hallucis muscle starts at the heel bone and attaches to the medial side of the first toe. Whenever it contracts, it plays a key role in elevating the medial longitudinal arch. Hence, the abductor hallucis muscle should be strong enough to control the depression on the medial longitudinal arch. The peroneus longus muscle plantarflexes the ankle and everts the ankle and subtalar joint. If this muscle contracts more than the abductor hallucis muscle does, the medial longitudinal arch of the foot is depressed. This study aimed to investigate the effect of myofascial release of the peroneus longus before performing the toe-tap exercise for strengthening the abductor hallucis muscle in participants with flexible pes planus. This cross-over study included 16 volunteers with flexible pes planus. The participants performed a toe-tap exercise before and after the myofascial release of the peroneus longus. During the toe-tap exercise, the muscle activity of the abductor hallucis and peroneus longus were measured using a Delsys Trigno Wireless Electromyography System. The angle of the medial longitudinal arch was measured using Image J software. Photos in the sagittal plane were used. The peroneus longus activity and medial longitudinal arch angles were significantly decreased. On the other hand, the activity of the abductor hallucis significantly increased after the myofascial release of the peroneus longus before performing the toe-tap exercise (p < 0.05). Individuals with flexible pes planus should be encouraged to perform myofascial release of the peroneus longus before the toe-tap exercise to improve the abductor hallucis activity and to elevate the medial longitudinal arch.

Assessment of a New Lateral Cushioned Casting Orthosis: Effects on Peroneus Longus Muscle Electromyographic Activity During Running

Background: Classical medial wedge (CMW) orthoses have been prescribed to treat overpronation foot pathologies in runners. The effects of a novel supination orthosis (NSO) on the surface electromyography (EMG) activity of the peroneus longus (PL) muscle during a complete cycle of running have yet to be tested. Purpose/Hypothesis: The purpose of this study was to compare the EMG activity of the PL in participants wearing CMW orthoses and NSOs versus neutral running shoes (NRS) during a full cycle of running gait. It was hypothesized that the PL muscle activity would be lower for the NSO compared with CMW or NRS. Study Design: Controlled laboratory study. Methods: Included were 31 healthy recreational runners of both sexes (14 male and 17 female; mean age, 38.58 ± 4.02 years) with a neutral Foot Posture Index and standard rearfoot-strike pattern. Participants ran on a treadmill at 9 km/h while wearing NSO (3-, 6-, and 9-mm thicknesses), CMW (3-, 6-, and 9-mm thicknesses), and NRS, for a total of 7 different conditions randomly selected, while the EMG signal activity of the PL was recorded for 30 seconds. Each trial was recorded 3 times, and the intraclass correlation coefficient (ICC) to test reliability of the measurements was calculated. The Wilcoxon pair to pair nonparametric test with Bonferroni correction was performed to analyze differences among the conditions. Results: The reliability of all assessments was almost perfect (ICC, >0.81). For both the CMW and NSO, regardless of thickness, the PL activity was statistically significantly lower compared with the NRS ( P < .05 for all). For all CMW thicknesses, the PL activity was lower compared with the respective NSO thicknesses, with the 3-mm thickness having the largest difference (CMW3mm, 18.63 ± 4.64 vs NSO3mm, 20.78 ± 4.99 mV; P < .001). Conclusion: Both CMW and NSO produced reduced EMG activity of the PL muscle; therefore, they can be prescribed to treat overpronation pathologies without associated PL strain concerns. In addition, the NSO saved the enhancement material placed on the medial-rear side of CMW, making it easier to wear sports shoes. Clinical Relevance: Knowing the safety of CMW and NSO will aid in understanding treatments for overpronation pathologies.

Comparing the Stiffness of Peroneus Longus Tendon Versus Hamstrings in Anterior Cruciate Ligament Reconstruction: A Biomechanical Study

Background: The use of autografts originating from either hamstring tendons or peroneus longus tendons is a surgical option in anterior cruciate ligament (ACL) reconstruction. Objectives: This research aimed to compare the tensile strength between the hamstring tendon and the peroneus longus tendon in ACL reconstruction. The hypothesis of this study was: Peroneus longus grafts have tensile strength equal to hamstring grafts based on living donor patients. Methods: This cross-sectional study was a biomechanical study examining means and standard deviations (SD) by comparing the tensile strength of peroneus longus tendons and hamstring tendons when used as autograft donors in ACL reconstruction. Results: In this study, 51 patients with reconstructive ACL were enrolled. The mean diameter of the hamstring tendon was 7.86 with SD ± 0.69, while the mean diameter of peroneus longus tendon was 7.67 with SD ± 0.63. The mean diameter of the peroneus longus graft was not significantly different. The mean displacement on the hamstring tendon was 2.44 with SD ± 0.42, while the peroneus longus tendon was 2.06 with SD ± 0.14. The peroneus longus tendon had significantly more tensile strength compared to the hamstring tendon. Conclusions: Diameter of the peroneus longus graft was not significantly different from the hamstring graft. However, the peroneus longus graft had more tensile strength than the hamstring graft based on living donor patients.

COMPARATIVE STUDY OF SINGLE BUNDLE ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION USING THE PERONEUS LONGUS TENDON AUTOGRAFT VERSUS HAMSTRING TENDON AUTOGRAFT

Introduction: Arthroscopic anterior cruciate ligament (ACL) reconstruction can be performed using autograft from various sources namely bone patellar tendon bone graft, hamstring graft, or peroneus longus tendon. Purpose of this study was to compare the clinical outcome and donor site morbidity of ACL reconstruction with peroneus longus tendon versus hamstring tendon autograft in patients with an isolated ACL injury. Methods: Patients who undervent isolated single bundle ACL reconstruction were allocated in peroneus and hamstring groups and observed prospectively. Functional score (IKDC, & Modified Cincinnati score) was recorded preoperatively and 1 year post-operatively. Graft diameter was measured intra-operatively. Donor site morbidity were assessed with thigh circumference measurments and ankle scoring by MRC grading and FADI Score. Results: 56 patients (28-Hamstring and 28-peroneus group) met the inclusion criteria. The average Peroneus longus graft diameter (8.8±0.8) was significantly larger than the Hamstring graft diameter (8.1±0.9). In terms of 1-year postoperative outcomes statistically there is very little comparable difference between both these grafts when used for arthroscopic ACL reconstruction. Conclusion: Our study brings forth the superior efficacy and quality of double stranded peroneus longus tendon autograft in term of good functional score (IKDC, & Modified Cincinnati score), larger graft diameter, less thigh hypotrophy, and excellent ankle function based on FADI Score. Prospective cohort study, level II. Abbreviations: ACL- Anterior cruciate ligament BPTB- Bone-patellar tendon-bone IKDC – International knee documentation committee FADI- Foot and ankle disability index.