OBJECTIVE: To report the clinical characteristics and treatment analysis of 3 cases of congenital ulnar collateral flexor contracture of the forearm and take a reference for clinic. METHODS: A total of 3 patients with congenital ulnar collateral flexor contracture of the forearm were admitted between February 2019 and August 2021. Two patients were male and 1 was female, and their ages were 16, 20, and 16 years, respectively. The disease durations were 8, 20, and 15 years, respectively. They all presented with flexion deformity of the proximal and distal interphalangeal joints of the middle, ring, and little fingers in the neutral or extended wrist position, and the deformity worsened in the extended wrist position. The total action motion (TAM) scores of 3 patients were 1 and the gradings were poor. The Carroll's hand function evaluation scores were 48, 55, and 57, and the grip strength indexes were 72.8, 78.4, and 30.5. Preoperative CT of case 2 showed a bony protrusion of the flexor digitorum profundus tendon at the proximal end of the ulna; and MRI of case 3 showed that the ulnar flexor digitorum profundus presented as a uniform cord. After diagnosis, all patients were treated with operation to release the denatured tendon, and functional exercise was started early after operation. RESULTS: The incisions of 3 patients healed by first intention. Three patients were followed up for 12, 35, and 12 months, respectively. The hand function and the movement range of the joints significantly improved, but the grip strength did not significantly improve. At last follow-up, TAM scores were 3, 4, and 4, respectively, among which 2 cases were excellent and 1 case was good. Carroll's hand function evaluation scores were 95, 90, and 94, and the grip strength indexes were 73.5, 81.3, and 34.2, respectively. CONCLUSION Congenital ulnar collateral flexor contracture is a rare clinical disease that should be distinguished from ischemic muscle contracture. The location of the contracture should be identified and appropriate surgical timing should be selected for surgical release. Active postoperative rehabilitation and functional exercise can achieve good hand function.
Humans ; Male ; Female ; Forearm/surgery* ; Contracture/surgery* ; Muscle, Skeletal ; Tendons/surgery* ; Ulna/surgery* ; Range of Motion, Articular

Hepatocellular carcinoma (HCC) is one of the most common malignancies and is a major cause of cancer-related mortalities worldwide (Forner et al., 2018; He et al., 2023). Sarcopenia is a syndrome characterized by an accelerated loss of skeletal muscle (SM) mass that may be age-related or the result of malnutrition in cancer patients (Cruz-Jentoft and Sayer, 2019). Preoperative sarcopenia in HCC patients treated with hepatectomy or liver transplantation is an independent risk factor for poor survival (Voron et al., 2015; van Vugt et al., 2016). Previous studies have used various criteria to define sarcopenia, including muscle area and density. However, the lack of standardized diagnostic methods for sarcopenia limits their clinical use. In 2018, the European Working Group on Sarcopenia in Older People (EWGSOP) renewed a consensus on the definition of sarcopenia: low muscle strength, loss of muscle quantity, and poor physical performance (Cruz-Jentoft et al., 2019). Radiological imaging-based measurement of muscle quantity or mass is most commonly used to evaluate the degree of sarcopenia. The gold standard is to measure the SM and/or psoas muscle (PM) area using abdominal computed tomography (CT) at the third lumbar vertebra (L3), as it is linearly correlated to whole-body SM mass (van Vugt et al., 2016). According to a "North American Expert Opinion Statement on Sarcopenia," SM index (SMI) is the preferred measure of sarcopenia (Carey et al., 2019). The variability between morphometric muscle indexes revealed that they have different clinical relevance and are generally not applicable to broader populations (Esser et al., 2019).
Humans ; Aged ; Sarcopenia/diagnostic imaging* ; Carcinoma, Hepatocellular/diagnostic imaging* ; Muscle, Skeletal/diagnostic imaging* ; Deep Learning ; Prognosis ; Radiomics ; Liver Neoplasms/diagnostic imaging* ; Retrospective Studies

Sensory conflict impacts postural control, yet its effect on cortico-muscular interaction remains underexplored. We aimed to investigate sensory conflict's influence on the cortico-muscular network and postural stability. We used a rotating platform and virtual reality to present subjects with congruent and incongruent sensory input, recorded EEG (electroencephalogram) and EMG (electromyogram) data, and constructed a directed connectivity network. The results suggest that, compared to sensory congruence, during sensory conflict: (1) connectivity among the sensorimotor, visual, and posterior parietal cortex generally decreases, (2) cortical control over the muscles is weakened, (3) feedback from muscles to the cortex is strengthened, and (4) the range of body sway increases and its complexity decreases. These results underline the intricate effects of sensory conflict on cortico-muscular networks. During the sensory conflict, the brain adaptively decreases the integration of conflicting information. Without this integrated information, cortical control over muscles may be lessened, whereas the muscle feedback may be enhanced in compensation.
Humans ; Muscle, Skeletal ; Electromyography/methods* ; Electroencephalography/methods* ; Brain ; Brain Mapping

Skeletal muscle plays a paramount role in physical activity, metabolism, and energy balance, while its homeostasis is being challenged by multiple unfavorable factors such as injury, aging, or obesity. Exosomes, a subset of extracellular vesicles, are now recognized as essential mediators of intercellular communication, holding great clinical potential in the treatment of skeletal muscle diseases. Herein, we outline the recent research progress in exosomal isolation, characterization, and mechanism of action, and emphatically discuss current advances in exosomes derived from multiple organs and tissues, and engineered exosomes regarding the regulation of physiological and pathological development of skeletal muscle. These remarkable advances expand our understanding of myogenesis and muscle diseases. Meanwhile, the engineered exosome, as an endogenous nanocarrier combined with advanced design methodologies of biomolecules, will help to open up innovative therapeutic perspectives for the treatment of muscle diseases.
Exosomes/physiology* ; Muscle, Skeletal/metabolism* ; Cell Communication ; Homeostasis

Severe muscle injury is hard to heal and always results in a poor prognosis. Recent studies found that extracellular vesicle-based therapy has promising prospects for regeneration medicine, however, whether extracellular vesicles have therapeutic effects on severe muscle injury is still unknown. Herein, we extracted apoptotic extracellular vesicles derived from mesenchymal stem cells (MSCs-ApoEVs) to treat cardiotoxin induced tibialis anterior (TA) injury and found that MSCs-ApoEVs promoted muscles regeneration and increased the proportion of multinucleated cells. Besides that, we also found that apoptosis was synchronized during myoblasts fusion and MSCs-ApoEVs promoted the apoptosis ratio as well as the fusion index of myoblasts. Furthermore, we revealed that MSCs-ApoEVs increased the relative level of creatine during myoblasts fusion, which was released via activated Pannexin 1 channel. Moreover, we also found that activated Pannexin 1 channel was highly expressed on the membrane of myoblasts-derived ApoEVs (Myo-ApoEVs) instead of apoptotic myoblasts, and creatine was the pivotal metabolite involved in myoblasts fusion. Collectively, our findings firstly revealed that MSCs-ApoEVs can promote muscle regeneration and elucidated that the new function of ApoEVs as passing inter-cell messages through releasing metabolites from activated Pannexin 1 channel, which will provide new evidence for extracellular vesicles-based therapy as well as improving the understanding of new functions of extracellular vesicles.
Creatine/metabolism* ; Extracellular Vesicles ; Muscle, Skeletal/metabolism* ; Myoblasts/metabolism* ; Regeneration ; Connexins/metabolism*

Skeletal muscle is one of the most important organs in animal, and the regulatory mechanism of skeletal muscle development is of great importance for the diagnosis of muscle-related diseases and the improvement of meat quality of livestock. The regulation of skeletal muscle development is a complex process, which is regulated by a large number of muscle secretory factors and signaling pathways. In addition, in order to maintain steady-state and maximum use of energy metabolism in the body, the body coordinates multiple tissues and organs to form the complex and sophisticated metabolic regulation network, which plays an important role for the regulation of skeletal muscle development. With the development of omics technologies, the underlying mechanism of tissue and organ communication has been deeply studied. This paper reviews the effects of crosstalk among adipose tissue, nerve tissue and intestinal tissue on skeletal muscle development, with the aim to provide a theoretical basis for targeted regulation of skeletal muscle development.
Animals ; Muscle, Skeletal/metabolism* ; Adipose Tissue/metabolism* ; Signal Transduction

The growth and development of skeletal muscle is an important factor affecting pork production and quality, which is elaborately regulated by many genetic and nutritional factors. MicroRNA (miRNA) is a non-coding RNA with a length of about 22 nt, which binds to the 3'UTR sequence of the mRNA of the target genes, and consequently regulates its post-transcriptional expression level. In recent years, a large number of studies have shown that miRNAs are involved in various life processes such as growth and development, reproduction, and diseases. The role of miRNAs in the regulation of porcine skeletal muscle development was reviewed, with the hope to provide a reference for the genetic improvement of pigs.
Swine ; Animals ; MicroRNAs/metabolism* ; Muscle, Skeletal/metabolism* ; Muscle Development/genetics*

Objective To investigate the clinical value of high-frequency ultrasound in the diagnosis of pronator teres syndrome (PTS). Methods The high-frequency ultrasound was employed to examine and measure the median nerve of the pronator teres muscle in 30 patients with PTS and 30 healthy volunteers (control group).The long-axis diameter (LA),short-axis diameter (SA) and cross-sectional area (CSA) of the median nerve were measured.The receiver operating characteristic curve of the median nerve ultrasonic measurement results was established,and the area under the curve (AUC) was calculated.The diagnostic efficiency of each index for PTS was compared with the surgical results as a reference. Results The PTS group showed larger LA[(5.02±0.50) mm vs.(3.89±0.41) mm;t=4.38,P=0.013],SA[(2.55±0.46) mm vs.(1.70±0.41) mm;t=5.19,P=0.009],and CSA[(11.13±3.72) mm² vs.(6.88±2.68) mm²;t=8.42,P=0.008] of the median nerve than the control group.The AUC of CSA,SA,and LA was 94.3% (95%CI=0.912-0.972,Z=3.586,P=0.001),77.7% (95%CI=0.734-0.815,Z=2.855, P=0.006),and 78.8% (95%CI=0.752-0.821,Z=3.091,P=0.004),respectively.With 8.63 mm² as the cutoff value,the sensitivity and specificity of CSA in diagnosing PTS were 93.3% and 90.0%,respectively. Conclusion High-frequency ultrasound is a practical method for diagnosing PTS,and the CSA of median nerve has a high diagnostic value.
Humans ; Forearm/innervation* ; Muscle, Skeletal/innervation* ; Median Nerve/diagnostic imaging* ; Ultrasonography/methods* ; Sensitivity and Specificity

OBJECTIVE: To summarize the clinical characteristics, differential diagnosis, and treatment methods of finger flexion contracture caused by three kinds of forearm flexor diseases. METHODS: Between December 2008 and August 2021, 17 patients with finger flexion contracture were treated, including 8 males and 9 females, aged 5-42 years, with a median of 16 years. The disease duration ranged from 1.5 months to 30 years, with a median of 13 years. The etiology included 6 cases of Volkmann's contracture, all of which were flexion deformity of the 2nd to 5th fingers, accompanied by limitation of thumb dorsiflexion in 3 cases and limitation of wrist dorsiflexion in 3 cases; 3 cases of pseudo-Volkmann's contracture, including 2 cases of flexion deformity of middle, ring, and little fingers, and 1 case of flexion deformity of ring and little fingers; 8 cases of ulnar finger flexion contracture caused by forearm flexor disease or anatomical variations, all of which were flexion deformity of middle, ring, and little fingers. Operations such as slide of flexor and pronator teres origin, excision of abnormal fibrous cord and bony prominence, and release of entrapped muscle (tendon) were performed. Hand function was evaluated according to WANG Haihua's hand function rating standard or modified Buck-Gramcko classification standard, and muscle strength was evaluated according to British Medical Research Council (MRC) muscle strength rating standard. RESULTS: All patients were followed up 1-10 years (median, 1.5 years). At last follow-up, 8 patients with contracture caused by forearm flexor disease or anatomical variations and 3 patients with pseudo-Volkmann's contracture achieved excellent hand function, with muscle strength of grade M5 in 6 cases and grade M4 in 5 cases. One patient with mild Volkmann's contracture and 3 patients with moderate Volkmann's contracture without severe nerve damage had excellent hand function in 2 cases and good in 2 cases, with muscle strength of grade M5 in 1 case and grade M4 in 3 cases. Two patients with moderate or severe Volkmann's contracture had poor hand function, with 1 case of muscle strength of grade M3 and 1 case of grade M2, which improved when compared with those before operation. The overall excellent and good rate of hand function and the proportion of patients with muscle strength of grade M4 and above were 88.2% (15/17), respectively. CONCLUSION The finger flexion contracture caused by different etiology can be differentiated by analyzing the history, physical examination, radiographs, and intraoperative findings. After different surgical treatments, such as resection of contracture band, release of compressed muscle (tendon), and downward movement of flexor origin, most patients have a good outcome.
Male ; Female ; Humans ; Forearm/surgery* ; Contracture/surgery* ; Ischemic Contracture/surgery* ; Fingers/surgery* ; Muscle, Skeletal/surgery*

OBJECTIVES: To explore the changes of elbow flexor muscle strength after musculocutaneous nerve injury and its correlation with needle electromyography (nEMG) parameters. METHODS: Thirty cases of elbow flexor weakness caused by unilateral brachial plexus injury (involving musculocutaneous nerve) were collected. The elbow flexor muscle strength was evaluated by manual muscle test (MMT) based on Lovett Scale. All subjects were divided into Group A (grade 1 and grade 2, 16 cases) and Group B (grade 3 and grade 4, 14 cases) according to their elbow flexor muscle strength of injured side. The biceps brachii of the injured side and the healthy side were examined by nEMG. The latency and amplitude of the compound muscle action potential (CMAP) were recorded. The type of recruitment response, the mean number of turns and the mean amplitude of recruitment potential were recorded when the subjects performed maximal voluntary contraction. The quantitative elbow flexor muscle strength was measured by portable microFET 2 Manual Muscle Tester. The percentage of residual elbow flexor muscle strength (the ratio of quantitative muscle strength of the injured side to the healthy side) was calculated. The differences of nEMG parameters, quantitative muscle strength and residual elbow flexor muscle strength between the two groups and between the injured side and the healthy side were compared. The correlation between elbow flexor manual muscle strength classification, quantitative muscle strength and nEMG parameters was analyzed. RESULTS: After musculocutaneous nerve injury, the percentage of residual elbow flexor muscle strength in Group B was 23.43% and that in Group A was 4.13%. Elbow flexor manual muscle strength classification was significantly correlated with the type of recruitment response, and the correlation coefficient was 0.886 (P<0.05). The quantitative elbow flexor muscle strength was correlated with the latency and amplitude of CMAP, the mean number of turns and the mean amplitude of recruitment potential, and the correlation coefficients were -0.528, 0.588, 0.465 and 0.426 (P<0.05), respectively. CONCLUSIONS The percentage of residual elbow flexor muscle strength can be used as the basis of muscle strength classification, and the comprehensive application of nEMG parameters can be used to infer quantitative elbow flexor muscle strength.
Humans ; Elbow ; Electromyography ; Musculocutaneous Nerve ; Elbow Joint/physiology* ; Muscle, Skeletal ; Muscle Strength ; Peripheral Nerve Injuries