Left Tibialis Anterior Muscle Research Articles

TRIM Enhances Angiogenesis in Dystrophic Muscle 140 Days Post Treatment

Background: Duchenne Muscular Dystrophy (DMD) causes limb muscle dysfunction and impaired mobility while promoting ischemia in effected muscles. For treatment, we developed a novel biomaterial, Time Release Ion Matrix (TRIM), that promotes angiogenesis and enhances muscle structure and function in dystrophic (D2. mdx) mice at 14- and 70-days post injection (dpi). Whether TRIM remains effective at 140 dpi is unknown. Hypothesis: At 140 dpi in D2. mdx mice TRIM will: 1) enhance isometric force and myofiber cross-sectional area (CSA) of the tibialis anterior (TA) muscle; and 2) stimulate angiogenic growth factors and increase vascularity. Methods: The right and left TA of adult male D2. mdx mice (male, n=7-8, age 7 months) were injected with saline alone (control) or 250 μg of TRIM suspended in saline. At 140 dpi, the left TA muscle was isolated for in situ muscle force measurements and histological analysis; the right TA was frozen for biochemical analysis. Muscle cross-sections were immunostained for laminin (myofiber borders), DAPI (nuclei), and CD31 (endothelial cells). Vascular endothelial growth factor (VEGF) ELISA and immunoblots were performed on muscle homogenates. Results: No difference in peak isometric force was recorded between groups at 140 dpi (means ± SE: TRIM, 65.4 ± 2.7g; Saline, 62.7 ± 1.5g; P= 0.34). TRIM enhanced the relative frequency of myofibers >1000 μm2 by 27% vs. saline (TRIM, 56 ± 2%; Saline, 44 ± 3%; P= 0.006). DAPI staining revealed a 36% increase in central nuclei indicating myofiber regeneration (TRIM, 30.0 ± 1.7%; Saline, 22.0% ± 2.5; P=0.02). Microvessel area (CD31 staining, μm2) was 2.5-fold greater in treated TA’s (TRIM, 131 ± 12 μm2; Saline, 53 ± 6 μm2, P=0.0001). In muscle homogenates, TRIM had no effect on [VEGF] (TRIM, 102 ± 5%; Saline, 100 ± 4%; P= 0.79), while STAT3 activation was greater (TRIM, 129 ± 11%; Saline, 100 ± 7%; P= 0.04). Conclusion: At 140 days following injection of TRIM into the TA muscle of dystrophic mice, peak isometric force was unchanged while myofiber CSA was enhanced. Furthermore, TRIM promotes angiogenic growth factors and muscle vascularity, which should promote the ability to sustain physical activity. University of Missouri Coulter Biomedical Accelerator (SSS), American Physiological Society SURF (AGN), Texas A&M Department of Kinesiology and Sport Management (ABM). This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Histological and biochemical changes in lymphatic vessels after skeletal muscle injury induced by lengthening contraction in male mice.

Lymphatic vessels are actively involved in the recovery process of inflamed tissues. However, the changes in intramuscular lymphatic vessels during inflammation caused by skeletal muscle injury remain unclear. Therefore, the purpose of this study was to clarify the changes in lymphatic vessels after skeletal muscle injury. The left tibialis anterior muscles of male mice were subjected to lengthening contractions (LC) for inducing skeletal muscle injury, and samples were collected on Days 2, 4, and 7 for examining changes in both the skeletal muscles and intramuscular lymphatic vessels. With hematoxylin-eosin staining, the inflammatory response was observed in myofibers on Days 2 and 4 after LC, whereas regeneration of myofibers was found on Day 7 after LC. The number and area of intramuscular lymphatic vessels analyzed by immunohistochemical staining with an antibody against lymphatic vessel endothelial hyaluronan receptor 1 were significantly increased only on Day 4 after LC. Based on the abovementioned results, intramuscular lymphatic vessels undergo morphological changes such as increase under the state of muscle inflammation. This study demonstrated that the morphology of intramuscular lymphatic vessels undergoes significant changes during the initial recovery phase following skeletal muscle injury.

The case of a 49-year-old man with involuntary toe movements.

A 49-year-old man presented with 3 years of leg pain and involuntary toe movements. He described the pain as mild burning, radiating from the left foot upward to the leg. On examination, there were involuntary continuous flexion-extension movements of his left toes (video). Strength, sensation, and reflexes were normal. Lumbosacral MRI demonstrated diffuse degenerative disc disease with multi-level mild-to-moderate foraminal stenosis. Nerve conduction studies were normal. EMG showed neurogenic potentials and active denervation changes in the left anterior tibial and soleus muscles consistent with radiculopathy. The diagnosis of painful legs and moving toes is discussed.

The duration of glucocorticoid treatment alters the anabolic response to high-force muscle contractions.

Glucocorticoids induce a myopathy that includes loss of muscle mass and strength. Resistance exercise may reverse the muscle loss because it induces an anabolic response characterized by increases in muscle protein synthesis and potentially suppressing protein breakdown. Whether resistance exercise induces an anabolic response in glucocorticoid myopathic muscle is unknown, which is a problem because long-term glucocorticoid exposure alters the expression of genes that may prevent an anabolic response by limiting activation of pathways such as the mechanistic target of rapamycin in complex 1 (mTORC1). The purpose of this study was to assess whether high-force contractions initiate an anabolic response in glucocorticoid myopathic muscle. The anabolic response was analyzed by treating female mice with dexamethasone (DEX) for 7 days or 15 days. After treatment, the left tibialis anterior muscle of all mice was contracted via electrical stimulation of the sciatic nerve. Muscles were harvested 4 h after contractions. Rates of muscle protein synthesis were estimated using the SUnSET method. After 7 days of treatment, high-force contractions increased protein synthesis and mTORC1 signaling in both groups. After 15 days of treatment, high-force contractions activated mTORC1 signaling equally in both groups, but protein synthesis was only increased in control mice. The failure to increase protein synthesis may be because baseline synthetic rates were elevated in DEX-treated mice. The LC3 II/I ratio marker of autophagy was decreased by contractions regardless of treatment duration. These data show duration of glucocorticoid treatment alters the anabolic response to high-force contractions.NEW & NOTEWORTHY Glucocorticoid myopathy is the most common, toxic, noninflammatory myopathy. Our work shows that high-force contractions increase protein synthesis in skeletal muscle following short-term glucocorticoid treatment. However, longer duration glucocorticoid treatment results in anabolic resistance to high-force contractions despite activation of the mechanistic target of rapamycin in complex 1 (mTORC1) signaling pathway. This work defines potential limits for high-force contractions to activate the processes that would restore lost muscle mass in glucocorticoid myopathic patients.

Muscle Protein Synthesis with a Hybrid Dairy and Plant-Based Protein Blend (P4) Is Equal to Whey Protein in a Murine Ageing Model after Fasting.

P4, a specific combination of dairy proteins (whey and casein) and plant-based protein isolates (pea and soy), has been shown to provide a more balanced amino acid (AA) profile than its single constituent proteins; however, less is known about how this translates to muscle protein synthesis (MPS). The aim of this study was to investigate the effect of P4 compared to whey or casein against fasted control on MPS. C57BL/6J mice, aged 25 months, were fasted overnight, followed by oral gavage of either whey, P4, casein, or water as a fasted control. Thirty minutes after ingestion, puromycin (0.04 µmol∙g-1 bodyweight) was subcutaneously injected; 30-min thereafter, mice were sacrificed. MPS was measured by the SUnSET method, and signalling proteins were determined in the left-tibialis anterior (TA) muscle by the WES technique. AA composition was determined in plasma and right-TA muscle. Dried blood spots (DBS) were analysed for postprandial AA dynamics at 10, 20, 45, 60 min. MPS was 1.6-fold increased with whey (p = 0.006) and 1.5-fold with P4 compared to fasted (p = 0.008), while no change was seen with casein. This was confirmed by a significant increase of phosphorylated/total ratio of 4E-BP1 for both whey (p = 0.012) and P4 (p = 0.001). No changes were observed in p70S6K and mTOR phosphorylation/total ratio with whey or P4. Intramuscular leucine levels were lower for P4 (0.71 µmol∙g dry weight-1) compared to whey (0.97 µmol∙g dry weight-1) (p = 0.0007). Ten minutes postprandial, DBS showed significantly increased blood AA levels of BCAAs, histidine, lysine, threonine, arginine, and tyrosine for P4 versus fasted. In conclusion, a hybrid mix of dairy and plant-based proteins (P4) resulted in a MPS response that was similar to whey protein in aged mice after fasting. This suggests that other anabolic triggers beyond leucine or the well-balanced amino acid profile and bioavailability of the blend benefit stimulation of MPS.

Focal Application of Neurotrophic Factors Augments Outcomes of Nerve-Muscle-Endplate Grafting Technique for Limb Muscle Reinnervation.

We have developed a novel muscle reinnervation technique called "nerve-muscle-endplate grafting (NMEG) in the native motor zone (NMZ)." This study aimed to augment the outcomes of the NMEG-NMZ (NN) by focal application of exogenous neurotrophic factors (ENFs) for limb reinnervation. Adult rats were used to conduct NN plus ENF (NN/ENF) and autologous nerve grafting (ANG, technique control). The nerve innervating the left tibialis anterior (TA) muscle was resected and the denervated TA was immediately treated with NN/ENF or ANG. For NN procedure, an NMEG pedicle was taken from the lateral gastrocnemius muscle and transferred to the NMZ of the denervated TA. For ANG, the nerve gap was bridged with sural nerve. Three months after treatment, the extent of functional and neuromuscular recovery was assessed by measuring static toe spread, maximal muscle force, wet muscle weight, regenerated axons, and innervated motor endplates (MEPs). NN/ENF resulted in 90% muscle force recovery of the treated TA, which is far superior to ANG (46%) and NN alone (79%) as reported elsewhere. Toe spread recovered up to 89 and 49% of the control for the NN/ENF and ANG groups, respectively. The average wet muscle weight was 87 and 52% of the control for muscles treated with NN/ENF and ANG, respectively. The mean number of the regenerated axons was 88% of the control for the muscles treated with NN/ENF, which was significantly larger than that for the ANG-repaired muscles (39%). The average percentage of the innervated MEPs in the NN/ENF-treated TA (89%) was higher compared with that in the ANG-repaired TA (48%). ENF enhances nerve regeneration and MEP reinnervation that further augment outcomes of NN. The NN technique could be an alternative option to treat denervated or paralyzed limb muscles caused by traumatic nerve injuries or lesions.

Reinnervation of Paralyzed Limb Muscle by Nerve-Muscle-Endplate Grafting Technique.

We have developed a novel reinnervation technique called nerve-muscle-endplate grafting in the native motor zone (NMEG-NMZ). However, it remains unknown whether the NMEG-NMZ is effective for limb reinnervation. To evaluate the efficacy of the NMEG-NMZ in limb muscle reinnervation. Forty-five adult rats were divided into 3 groups: NMEG, end-to-end anastomosis (EEA, technique control), and denervation control (DC). The left tibialis anterior muscle was denervated by resecting its nerve. For NMEG-NMZ, the denervated tibialis anterior was reinnervated by transferring a NMEG pedicle from the lateral gastrocnemius muscle. Three months after surgery, static toe spread analysis was performed for all rats and muscle force was measured for the rats treated with NMEG and EEA. Muscle weight, myofiber morphology, regenerated axons, and reinnervated motor endplates in the treated muscles were also quantified and compared with those in the DC group. NMEG-NMZ technique resulted in better muscle force recovery (79% of the control) compared with EEA (51% of the control, P = .048). Toe spread analysis in NMEG-NMZ reinnervated muscles showed static sciatic index = -16.8, whereas -41.4 in EEA, P < .0001). The average weight of the NMEG-NMZ reinnervated muscles (86%) was greater than those of the EEA treated (71%) and DC (26%) muscles (all P < .0001). The mean count of the regenerated axons in the muscles with NMEG-NMZ was 76% of the control, which was larger than that in the muscles with EEA (46%), P < .0001. NMEG-NMZ technique has unique advantages and is superior to EEA for muscle reinnervation and functional recovery.

Changes to the Skeletal Muscle Gene Expression Signature in Response to Nutrient and/or Mechanical Stimuli

Nutrient consumption and mechanical overload influence skeletal muscle metabolism and function. These metabolic and functional outcomes are mediated at least in part by changes to the types of genes that are expressed in skeletal muscle. The extent to which nutrient consumption and mechanical overload act synergistically or independent of each other to change the skeletal muscle gene expression signature remains ill defined. Therefore, the purpose of this study was to define the differential and conserved gene expression responses to either nutrient consumption or mechanical overload as well as the combination of these stimuli. Published RNA‐Seq data sets generated from the muscle of humans subjected to acute resistance exercise were uploaded into the Database for Annotation Visualization and Integrated Discovery (DAVID) to define important functional gene categories related to muscle metabolism and/or function. Genes from the functional categories of ‘cell cycle’, ‘FoxO pathway’, and ‘transcription’ were marked for analysis in a mouse model of acute feeding and mechanical overload. For this model, C57BL/6 mice were initially fasted beginning at 1700 hr. The next morning (0800‐1000 hr), mice were randomized to remain fasted or allowed access to food for 30 min. Then, a mechanical overload was placed upon the left tibialis anterior (TA) muscle of all mice by subjecting the muscle to 10 sets of 6 eccentric muscle contractions by unilateral electrical stimulation of the sciatic nerve. The contralateral TA served as the non‐overloaded control muscle. All mice were deprived of food following the contractions protocol until euthanasia 4 hr later. The relative mRNA expression of Gadd45a, Usp2, Foxo1, Foxo3, and Myod1 were determined by RT‐PCR. Feeding and contractions each decreased the mRNA expression of Gadd45a (cell cycle), Foxo1, and Foxo3 (FoxO pathway), with the combination of feeding and contractions acting to synergistically decrease the expression of each gene. Conversely, the mRNA expression of Usp2 (cell cycle) was decreased in response to muscle contractions, with no effect of feeding noted. Finally, the mRNA expression of Myod1 (transcription) was significantly increased in response to feeding, with contractions causing a differential change in direction of Myod1 mRNA expression depending upon the fasting/feeding state. These data show that nutrient consumption and mechanical overload have shared and differential effects on the skeletal muscle gene expression signature. A more thorough understanding of the genetic changes regulated by each stimulus alone, as well as the combination of stimuli, will provide novel insight for how nutrients and mechanical overload alter metabolism and function in muscle.

Ultrasound Stimulation Inhibits Morphological Degeneration of Motor Endplates in the Denervated Skeletal Muscle of Rats.

Recovery of motor function after peripheral nerve injury requires treatment of the neuromuscular junction (NMJ), as well as the injured nerve and skeletal muscle. The purpose of this study was to examine the effects of ultrasound (US) stimulation on NMJ degeneration after denervation using a rat model of peroneal nerve transection. Twelve-week-old male Wistar rats were randomly assigned to 3 groups: US stimulation, sham stimulation, and intact. US or sham stimulation was performed on the left tibialis anterior (TA) muscle starting the day after peroneal nerve transection for 5 minutes daily under anesthesia. Four weeks later, the number and morphology of the motor endplates were analyzed to assess NMJ in the TA muscle. The endplates were classified as normal, partially fragmented, or fully fragmented for morphometric analysis. In addition, the number of terminal Schwann cells (tSCs) per endplate and percentage of endplates with tSCs (tSC retention percentage) were calculated to evaluate the effect of tSCs on NMJs. Our results showed that endplates degenerated 4 weeks after transection, with a decrease in the normal type and an increase in the fully fragmented type in both the US and sham groups compared to the intact group. Furthermore, the US group showed significant suppression of the normal type decrease and a fully fragmented type increase compared to the sham group. These results suggest that US stimulation inhibits endplate degeneration in denervated TA muscles. In contrast, the number of endplates and tSC and tSC retention percentages were not significantly different between the US and sham groups. Further investigations are required to determine the molecular mechanisms by which US stimulation suppresses degeneration.

Adeno-associated virus-mediated expression of an inactive CaMKIIβ mutant enhances muscle mass and strength in mice

A concurrent reduction in muscle mass and strength is frequently observed in numerous conditions, including neuromuscular disease, ageing, and muscle inactivity due to limb immobilization or prolonged bed rest. Thus, identifying the molecular mechanisms that control skeletal muscle mass and strength is fundamental for developing interventions aimed at counteracting muscle loss (muscle atrophy). It was recently reported that muscle atrophy induced by denervation of motor nerves was associated with increased expression of Ca2+/calmodulin-dependent protein serine/threonine kinase II β (CaMKIIβ) in muscle. In addition, treatment with KN-93 phosphate, which inhibits CaMKII-family kinases, partly suppressed denervation-induced muscle atrophy. Therefore, to test a possible role for CaMKIIβ in muscle mass regulation, we generated and injected recombinant adeno-associated virus (AAV) vectors encoding wild-type (AAV-WT), inactive (AAV-K43 M), or constitutively active (AAV-T287D) CaMKIIβ into the left hindlimb tibialis anterior muscle of mice at three months of age. Although AAV-WT infection induced expression of exogenous CaMKIIβ in the hindlimb muscle, no significant changes in muscle mass and strength were observed. By contrast, AAV-K43 M or AAV-T287D infection induced exogenous expression of the corresponding mutants and significantly increased or decreased the muscle mass and strength of the infected hind limb, respectively. Together, these findings demonstrate the potential of CaMKIIβ as a novel therapeutic target for enhancing muscle mass and strength.

Low-dose Droperidol Reduces the Amplitude of Transcranial Electrical Motor-evoked Potential: A Randomized, Double-blind, Placebo-controlled Trial.

Low-dose droperidol has been reported to suppress the amplitude of transcranial electrical motor-evoked potentials (TCE-MEPs), but no randomized controlled trials have been conducted to assess this. This randomized, double-blinded, placebo-controlled trial aimed to test the hypothesis that low-dose droperidol reduced TCE-MEP amplitudes. Twenty female patients with adolescent idiopathic scoliosis, aged between 12 and 20 years, and scheduled to undergo corrective surgery were randomly allocated to receive droperidol (20 µg/kg) or 0.9% saline. After recording baseline TCE-MEPs, the test drug was administered, following which TCE-MEP recordings were carried out every 2 minutes for up to 10 minutes. The primary outcome was the minimum relative TCE-MEP amplitude (peak-to-peak amplitude, percentage of baseline value) recorded in the left tibialis anterior muscle. Secondary outcomes included minimum relative MEP amplitudes recorded from all other muscle groups monitored in the study. Data are expressed as medians (interquartile range). The TCE-MEP amplitude of the left tibialis anterior muscle was significantly reduced following droperidol administration compared with saline (37% [30% to 55%] vs. 76% [58% to 93%], respectively, P <0.01). In the other muscles, the amplitudes were reduced in the droperidol group, except for the bilateral abductor pollicis brevis and the left quadriceps femoris muscles. The relative amplitude of the bilateral F waves recorded from the gastrocnemius was decreased in the droperidol group. Low-dose droperidol (20 µg/kg) reduced TCE-MEP amplitudes. Anesthesiologists should pay attention to the timing of droperidol administration during intraoperative TCE-MEP recordings, even if used in a low dose.

Effect of intermittent high-frequency stimulation on muscle velocity recovery cycle recordings.

The technique of multifiber muscle velocity recovery cycle recordings was developed as a diagnostic tool to assess muscle membrane potential changes and ion channel function in vivo. This study was undertaken to assess the impact of intermittent high-frequency stimulation on muscle velocity recovery cycle components and to study whether the changes can be modified by endurance training. We recorded muscle velocity recovery cycles with 1 and 2 conditioning stimuli in the left tibialis anterior muscle in 15 healthy subjects during intermittent 37-Hz stimulation and analyzed its effects on the different phases of supernormality. Recordings were conducted before and after 2-wk endurance training. Training effect was assessed by measuring the difference in endurance time, peak force, and limb circumference. Muscle velocity recovery cycle recordings during intermittent high-frequency stimulation were successfully recorded in 12 subjects. Supernormality for interstimulus intervals shorter than 15 ms (early supernormality) was maximally reduced at the beginning of repetitive stimulation and recovered during stimulation. Supernormality for interstimulus intervals between 50 and 150 ms (late supernormality) showed a delayed decrease and stayed significantly reduced after high-frequency stimulation. Training had no significant effect on any of the measured parameters, but we found that training induced changes in peak force correlated positively with baseline changes of early supernormality. Our results support the hypothesis that early supernormality represents membrane potential, which depolarizes in the beginning of high-frequency stimulation. Late supernormality probably reflects transverse tubular function and shows progressive changes during high-frequency stimulation with delayed normalization.NEW & NOTEWORTHY A conditioning impulse in human muscle fibers induces a prolonged phase of increased velocity (also called supernormality) with two phases related to an early and late afterpotential. We investigated the effects of intermittent 37-Hz stimulation on muscle fiber supernormality and found that the early and late phases of supernormality changed differently, and that the late phase may reflect the ionic interactions responsible for the counter-regulation of muscle fatigue.

P-MD017. Spinal segmental myoclonus masquerading as a pshycogenic movement disorder

Introduction . Spinal generated movement disorders are uncommon. An elderly gentleman presented with distressing jerks of both lower limbs which caused him much social embarrassment. He had received psychiatric treatment for these abnormal muscular spasms without relief. He had become depressed and withdrawn when he first presented to our outpatient department. In view of his clinical presentation, long term video EEG was done with simultaneous EMG recording from the left tibialis anterior muscle. During his hospital stay, this gentleman experienced several involuntary rhythmic contractions of both legs. The movements were characterized by a sudden brief flexion of the trunk and hips with the thighs and legs bending forwards and ankles dorsiflexing. The patient was fully conscious, alert and awake during the attack. These jerks occurred in the recumbent position, but he could lose his balance if they occurred on standing. These attacks were not stimulus sensitive and could be provoked by stress. Myoclonic jerks of both lower limbs were recorded with no EEG correlate. During jerking, EMG recording showed persistent contractions of the left tibialis muscle occurring at frequency of 4–8 bursts per second, with each burst comprising of 4–5 motor unit discharges. The burst of tibialis anterior muscle activity was involuntary and was absent during voluntary leg movements. Results . A routine clinical examination followed by a long-term video EEG with simultaneous EMG clinched the diagnosis of a spinal segmental myoclonus. He underwent spinal decompression surgery with fixation followed by treatment with levetericetam and clonazepam which relieved his symptoms. Conclusion . Spinal generated movement disorders are uncommon and are often attributed to a psychiatric disorder in the absence of a better explanation. We take this opportunity to elaborate on the case details, investigations and the treatment of spinal myoclonus.

테니스 플랫 서브 후 스플릿 스텝 동작의 근활성도 비교분석

The purpose of this study was to compare and analyze the muscle activity of the split-step motion after a tennis flat serve. This study obtained the following results. First, in phase 1 of the skilled and unskilled, the average muscle activity was significant in the left and right spinal erect muscles, left rectus femoris, right medial large muscles, left and right lateral vastus muscles, right biceps femoris, left and right tibialis anterior muscles, and right gastrocnemius It appeared to show a difference. And the maximum muscle activity of Phase 1 was found to be significantly different in the right vertebral erection muscle, medial vastus muscle, lateral vastus muscle, and biceps femoris. Second, the average muscle activity in phase 2 of the skilled and the unskilled showed a significant difference in the left and right medial latissimus, biceps femoris, gastrocnemius, and right lateral vastus. And the maximum muscle activity of phase2 was found to be significantly different in the left rectus femoris, right medial latissimus, lateral latissimus dorsi, and gastrocnemius. Third, the average muscle activity in phase 3 of the skilled and the unskilled showed a significant difference in the left and right rectus femoris, the right medial vastus, lateral vastus, tibialis anterior, and gastrocnemius. And the maximum muscle activity of phase3 showed significant differences in the right rectus femoris, medial latissimus, biceps femoris, and gastrocnemius. Fourth, the average muscle activity in phase 4 of the skilled and the unskilled showed a significant difference in the left rectus femoris, medial latissimus, tibialis anterior, and gastrocnemius. In addition, the maximum muscle activity of phase 4 showed a significant difference in the left rectus femoris and tibialis anterior muscles.

Effect of biomechanical footwear on upper and lower leg muscle activity in comparison with knee brace and normal walking

AimTo evaluate the activity of knee stabilizing muscles while using custom-made biomechanical footwear (BF) and to compare it when walking barefoot and with a knee brace (Unloader®). MethodsSeventeen healthy working-aged (mean age: 29 years; standard deviation: 8 years) individuals participated. The knee brace was worn on the right knee and BF in both legs. Surface electromyography (sEMG) data was recorded bilaterally from vastus medialis (VM), semitendinosus (ST), tibialis anterior (TA) and lateral gastrocnemius (LG) muscles during walking, and repeated-measures ANOVA with a post-hoc t-test was used to determine differences between the different walking modalities (barefoot, brace and BF). ResultsAveraged sEMG was significantly higher when walking with BF than barefoot or knee brace in the ST muscles, in the right LG, and left TA muscle. It was significantly lower when walking with the brace compared to barefoot in the right ST and LG muscles, and left TA muscle. Analysis of the ensemble-averaged sEMG profiles showed earlier activation of TA muscles when walking with BF compared to other walking modalities. ConclusionBF produced greater activation in evaluated lower leg muscles compared to barefoot walking. Thus BF may have an exercise effect in rehabilitation and further studies about its effectiveness are warranted.

The effects of wearing high heeled shoes on the muscles and joints of lower limb

Abstract Study aim: The aim of this study is to investigate whether the lower extremity muscles’ force/torque/strength and range of motion may be affected in females wearing high heeled shoes and not wearing high heeled shoes. Material and methods: The study was carried out with 136 females aged between 18 and 45 years. The first group consisted of 66 females wearing 5 cm or higher high heeled shoes. The second group consisted of 70 females wearing shoes having heel height less than 5 cm. The Nicholas Manual Muscle Tester was used to evaluate lower extremity muscle force/torque/strength, while range of motion was assessed with an electronic goniometer. The SPSS 21.0 program was used for statistical analysis. Results: A significant difference was found in the lower extremity muscles’ force (except for hip adduction, dorsiflexion, metatarsophalangeal joint and interphalangeal joint extension), and muscles’ torque (except for hip adduction, dorsiflexion and left tibialis anterior muscle) and muscles’ strength values (except for hip adduction, dorsiflexion and tibialis anterior muscle). Also, as heel height increased, the range of motion of hip joint flexion, internal rotation and plantar flexion increased significantly. Conclusions: Excessive use of high heeled shoes can cause changes in muscle force/torque/strength and joint range of motion.

Minimally Invasive Muscle Embedding Generates Donor-Cell-Derived Muscle Fibers that Express Desmin and Dystrophin.

The aim of this study was to quantify the extent of donor-cell-derived myogenesis achieved by a novel surgical technique known as Minimally Invasive Muscle Embedding (MIME). Through MIME, we implanted a single extensor digitorum longus muscle from donor mice (N=2) that expressed a red fluorescent protein (RFP), into the left tibialis anterior (TA) muscle of immunodeficient host mice (N=4) that expressed a green fluorescent protein (GFP). Soon after MIME, we injected a myotoxin (barium chloride), into the host TA muscle, to trigger concerted muscle degeneration and regeneration. In lieu of MIME, we performed a SHAM procedure on the right TA muscle of the same set of animals. In MIME-treated muscles, 22%±7% and 78%±7% muscle fibers were RFP+ and GFP+, respectively (mean±standard deviation); and all RFP+ fibers were positive for desmin and dystrophin. Conclusion. We conclude that MIME helps generate muscle fibers of donor origin, in host muscle.

Comparison of activation rates in the main muscle group in the performance of Turkish folk dances

Folk dances are “spiritual culture” in terms of music, lyrics, movement and presentation features. Also, folk dances are the “material culture” in terms of instruments, clothes and equipment. Folk dances are intertwined with many disciplines, due to its different features such as music, instrument, language, religion, literature, history, clothes, sport, stage, art, sociology, consideration and intelligence.&#x0D; There is no folk dance without music and rhythm. However, almost all of our women's dances and most of our men's dances are verbal. Therefore, folk dances are composed of lyrics, music and movement.&#x0D; Folk dances have a sportive dimension as well as a cultural dimension. Although folk dances have been examined with the dimension of movement until present day, we see that the researches on physical, physiological and kinesiological aspects are not sufficient. The main purpose of this study was to determine the contraction rates of muscles during the performance of folk dances.&#x0D; In this study, it has been identified 42 dances in Turkey, which movement and structural features are different from each other. These dances include 6 different “bar” type, 12 of “halay” type, 8 of “horon” type, 5 of “karşılama” type, and 11 of “zeybek” type. The study was completed using these dances.&#x0D; The study is derived from the author's “Analysis of Turkish Folk Dances from the Perspective of Movement Science and Culture” doctoral dissertation titled.&#x0D; The study was conducted in the main muscle group according to expert opinions and recommendations. The main muscle groups are Tibialis Anterior, Quadriceps Femoris, Flexor Digitorum Superficialis, Biceps Brachii, Longissimus Thoracis and Trapezius muscles.&#x0D; Electrodes were attached to the main muscles used in the folk dances. The measurements were obtained by bio-trace programme and data were defined in microvolt.&#x0D; As a result of the study, in the performance of Turkish folk dances on the type at the scale of Turkey, left Tibialis Anterior muscle (112.40), left Quadriceps Femoris muscle (112.32); the right Flexor Digitorum Superficialis muscle in the arm (49.63), the right Biceps Brachii muscle (60.07); the left Longissimus Thoracis muscle (46.68) and the right Trapezius muscle (104.19) contracted more.&#x0D; Determining the ratio in muscle contractions in folk dances provides valuable information which can be used in coordination exercises, motor development, training in a specific sport and also in physical therapy.

BiAb Mediated Restoration of the Linkage between Dystroglycan and Laminin-211 as a Therapeutic Approach for α-Dystroglycanopathies.

Patients with α-dystroglycanopathies, a subgroup of rare congenital muscular dystrophies, present with a spectrum of clinical manifestations that includes muscular dystrophy as well as CNS and ocular abnormalities. Although patients with α-dystroglycanopathies are genetically heterogeneous, they share a common defect of aberrant post-translational glycosylation modification of the dystroglycan alpha-subunit, which renders it defective in binding to several extracellular ligands such as laminin-211 in skeletal muscles, agrin in neuromuscular junctions, neurexin in the CNS, and pikachurin in the eye, leading to various symptoms. The genetic heterogeneity associated with the development of α-dystroglycanopathies poses significant challenges to developing a generalized treatment to address the spectrum of genetic defects. Here, we propose the development of a bispecific antibody (biAb) that functions as a surrogate molecular linker to reconnect laminin-211 and the dystroglycan beta-subunit to ameliorate sarcolemmal fragility, a primary pathology in patients with α-dystroglycan-related muscular dystrophies. We show that the treatment of LARGEmyd-3J mice, an α-dystroglycanopathy model, with the biAb improved muscle function and protected muscles from exercise-induced damage. These results demonstrate the viability of a biAb that binds to laminin-211 and dystroglycan simultaneously as a potential treatment for patients with α-dystroglycanopathy.

A Bolus Dose of Ketamine Reduces the Amplitude of the Transcranial Electrical Motor-evoked Potential: A Randomized, Double-blinded, Placebo-controlled Study.

A low-dose bolus or infusion of ketamine does not affect transcranial electrical motor-evoked potential (MEP) amplitude, but a dose ≥1 mg/kg may reduce MEP amplitude. We conducted a randomized, double-blinded, placebo-controlled study to evaluate the effect of ketamine (1 mg/kg) on transcranial electrical MEP. Twenty female patients (aged 12 to 18 y) with adolescent idiopathic scoliosis scheduled to undergo posterior spinal fusion were randomly allocated to receive ketamine or saline. General anesthesia was induced and maintained with continuous infusions of propofol and remifentanil. MEP was elicited by supramaximal transcranial electrical stimulation. MEP recordings were obtained at baseline and then at 2, 4, 6, 8, and 10 minutes after administration of ketamine (1 mg/kg) or saline (0.1 ml/kg). The primary endpoint was the minimum relative MEP amplitude (peak-to-peak amplitude, % of baseline value) recorded from the left tibialis anterior muscle. The baseline amplitude recorded before test drug administration was defined as 100%. Medians (interquartile range) minimum MEP amplitudes in the left tibialis anterior muscle in the ketamine and saline groups were 26% (9% to 34%) and 87% (55% to 103%) of the baseline value, respectively (P<0.001). MEP amplitudes in other muscles were significantly reduced by ketamine. The suppressive effect of ketamine lasted for at least 10 minutes in each muscle. A 1-mg/kg bolus dose of ketamine can reduce MEP amplitude. Anesthesiologists should consider the dosage and timing of intravenous ketamine administration during MEP monitoring.