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

OBJECTIVES: To observe the effects of electroacupuncture (EA) at "Jiaji" (EX-B 2) combined with neurodynamic mobilization (NM) on the cross-sectional area of the gastrocnemius muscle fibers after sciatic nerve injury in rabbits, and the expression of nuclear factor κB (NF-κB) and muscle-specific ring-finger protein 1 (MuRF1). METHODS: A total of 180 common-grade New Zealand rabbits (half male and half female) were randomly divided into five groups, i.e. a normal control group, a model control group, a NM group, an EA group and a combined intervention group, 36 rabbits in each group. Except in the normal control group, clipping method was used to prepare the model of sciatic nerve injury in the rest groups. On the 3rd day of successful modeling, NM was delivered in the NM group. In the EA group, EA was exerted at bilateral "Jiaji" (EX-B 2) of L₄ to L₆, stimulated with disperse-dense wave and the frequency of 2 Hz/100 Hz. In the combined intervention group, after EA delivered at bilateral "Jiaji" (EX-B 2) of L₄ to L₆ , NM was operated. The intervention in each group was delivered once daily, for 6 days a week, and lasted 1, 2 or 4 weeks according to the collection time of sample tissue. After 1, 2 and 4 weeks of intervention, in each group, the toe tension reflex score and the modified Tarlov test score were observed; the morphology of the gastrocnemius muscle was observed by HE staining and the cross-sectional area of muscular fiber was measured; using Western blot method, the expression of NF-κB and MuRF1 of the gastrocnemius muscle was detected. RESULTS: After 1, 2 and 4 weeks of intervention, the toe tension reflex scores and the modified Tarlov scores in the model control group were lower than those of the normal control group (P<0.05), and these two scores in the NM group, the EA group and the combined intervention group were all higher than those of the model control group (P<0.05); the scores in the combined intervention group were higher than those in the EA group and the NM group (P<0.05). The gastrocnemius fibers were well arranged and the myocyte morphology was normal in the normal control group. In the model control group, the gastrocnemius fibers were disarranged, the myocytes were irregular in morphology and the inflammatory cells were infiltrated in the local. In the NM group, the EA group and the combined intervention group, the muscle fibers were regularly arranged when compared with the model control group. After 1, 2 and 4 weeks of intervention, the cross-sectional areas of the gastrocnemius muscle fibers in the model control group were smaller than those of the normal control group (P<0.05). The cross-sectional areas in the NM group, the EA group and the combined intervention group were larger than those of the model control group (P<0.05), and the cross-sectional areas in the combined intervention group were larger than those in the NM group and the EA group (P<0.05). After intervention for 1, 2 and 4 weeks, the protein expressions of NF-κB and MuRF1 in the gastrocnemius muscle were higher in the model control group in comparison of those in the normal control group (P<0.05). In the NM group, the EA group and the combined intervention group, the expressions of NF-κB after intervention for 1, 2 and 4 weeks and the expressions of MuRF1 after 2 and 4 weeks of intervention were lower when compared with those in the model control group (P<0.05). In the combined intervention group, the protein expressions of NF-κB after intervention for 1, 2 and 4 weeks and the expressions of MuRF1 after 2 and 4 weeks of intervention were decreased when compared with those in the NM group and the EA group (P<0.05). CONCLUSIONS Electroacupuncture at "Jiaji" (EX-B 2) combined with NM may increase the muscle strength and sciatic function and alleviate gastrocnemius muscle atrophy in the rabbits with sciatic nerve injury. The underlying mechanism is related to the inhibition of NF-κB and MuRF1 expression.
Animals ; Female ; Male ; Rabbits ; Electroacupuncture ; Muscle, Skeletal ; Muscular Atrophy/therapy* ; NF-kappa B/genetics* ; Peripheral Nerve Injuries ; Rats, Sprague-Dawley ; Sciatic Nerve

The surgical treatment of massive rotator cuff tears is a clinical challenge for orthopaedic surgeons. Moreover, tendon retraction, adhesions and fatty infiltration after rotator cuff tear will further increase the difficulty of surgical repair. Therefore, it has become a hotspot and difficulty to repair massive rotator cuff tears with a better way in current research. In recent years, with the continuous development of arthroscopic techniques, shoulder arthroscopic surgery has become the gold standard for the treatment of massive rotator cuff tears, but the adaptations, effects and combined application of different surgical methods are still controversial. The author believes that arthroscopic debridement of shoulder joint and acromioplasty or tuberoplasty could relieve shoulder pain in the short-term for elderly patients with lower functional requirements;long biceps tenotomy or tenodesis is effective for patients with biceps long head tendon injury; complete repair is still the first line treatment for massive rotator cuff tears, but partial repair is possible for massive rotator cuff tears that could not be completely repaired;patch augmentation technology could bring good results for young patients with high functional requirements;for patients with limited internal and external rotation of the shoulder joint and high functional requirements, tendon transfers surgery is recommended;superior capsular reconstruction is more advantageous for young patients with no obvious glenohumeral arthritis, better deltoid muscle strength and higher functional requirements. In addition, subacromial spacer implantation has become a current research hotspot due to its advantages of small trauma, low cost and relative safety, and its long-term effect still needs to be further confirmed.
Humans ; Aged ; Rotator Cuff Injuries/surgery* ; Arthroscopy/methods* ; Tendons ; Muscle, Skeletal/surgery* ; Tendon Injuries/surgery* ; Treatment Outcome

Objective To screen serum biomarkers after skeletal muscle contusion in rats based on gas chromatography-mass spectrometry （GC-MS） metabolomics technology, and support vector machine （SVM） regression model was established to estimate skeletal muscle contusion time. Methods The 60 healthy SD rats were randomly divided into experimental group （n=50）, control group （n=5） and validation group （n=5）. The rats in the experimental group and the validation group were used to establish the model of skeletal muscle contusion through free fall method, the rats in experimental group were executed at 0 h, 2 h, 4 h, 8 h, 12 h, 24 h, 48 h, 96 h, 144 h and 240 h, respectively, and the rats in validation group were executed at 192 h, while the rats in the control group were executed after three days' regular feeding. The skeletal muscles were stained with hematoxylin-eosin （HE）. The serum metabolite spectrum was detected by GC-MS, and orthogonal partial least square-discriminant analysis （OPLS-DA） pattern recognition method was used to discriminate the data and select biomarkers. The SVM regression model was established to estimate the contusion time. Results The 31 biomarkers were initially screened by metabolomics method and 6 biomarkers were further selected. There was no regularity in the changes of the relative content of the 6 biomarkers with the contusion time and the SVM regression model can be successfully established according to the data of 6 biomarkers and the 31 biomarkers. Compared with the injury time ［（55.344±7.485） h］ estimated from the SVM regression model based on the data of 6 biomarkers, the injury time ［（195.781±1.629） h］ estimated from the SVM regression model based on the data of 31 biomarkers was closer to the actual value. Conclusion The SVM regression model based on metabolites data can be used for the contusion time estimation of skeletal muscles.
Animals ; Biomarkers ; Contusions ; Discriminant Analysis ; Metabolomics ; Muscle, Skeletal/injuries* ; Rats ; Rats, Sprague-Dawley

To explore the value of conventional ultrasound combined with shear-wave elastography in the quantitative evaluation of sciatic nerve crush injury in rabbit models. Forty healthy male New Zealand white rabbits were randomly divided into four groups (=10 in each group):three crush injury (CI) groups (2,4,and 8 weeks after crush) and control group (without injury). The thickness and stiffness of the crushed sciatic nerves and denervated triceps surae muscles were measured at different time points and compared with histopathologic parameters. Inter-reader variability was assessed with intraclass correlation coefficients. Compared with the control group,the inner diameters of the sciatic nerves significantly increased in the 2-week CI group [(1.65±0.34) mm (0.97±0.15) mm,=0.00] but recovered to the nearly normal level in the 8-week CI group [(1.12±0.18) mm (0.97±0.15) mm,=0.06];however,compared with control group [(8.75±1.02)kPa],the elastic modulus of the nerves increased significantly in all the CI groups [2-week:(14.77±2.53) kPa;4-week:(19.12±3.46) kPa;and 8-week:(28.39±5.26) kPa;all =0.00];pathologically,massive hyperplasia of collagen fibers were found in the nerve tissues. The thickness of denervated triceps surae muscle decreased gradually,and the elastic modulus decreased 2 weeks after injury but increased gradually in the following 6 weeks;pathologically,massive hyperplasia of collagen fibers and adipocytes infiltration were visible,along with decreased muscle wet-weight ratio and muscle fiber cross-sectional area. The inter-reader agreements were good. Conventional ultrasound combined with shear-wave elastography is feasible for the quantitative evaluation of the morphological and mechanical properties of crushed nerves and denervated muscles.
Animals ; Crush Injuries ; diagnostic imaging ; Elastic Modulus ; Elasticity Imaging Techniques ; Male ; Muscle, Skeletal ; innervation ; pathology ; Rabbits ; Random Allocation ; Sciatic Nerve ; injuries ; Ultrasonography

PURPOSE: Defects around the distal one third of the leg and ankle are difficult to manage by conservative measures or simple split thickness skin graft. Distally based peroneus brevis muscle flap is a well described flap for such defects. METHODS: This is a retrospective analysis conducted on 25 patients with soft tissue and bony defects of distal third of lower leg and ankle, which were treated using distally based peroneus brevis muscle flap from January 2013 to January 2018. Information regarding patient demographics, etiology, size and location of defects and complications were collected. All patients were followed up for at least 3 months after surgery. RESULTS: There were 21 males and 4 females with the mean age of 39 (5-76) years. The most common cause of injuries was road traffic accident, followed by complicated open injury. The average size of defects was 20 (4-50) cm. The mean operating time was 75 (60-90) min for flap harvest and inset. We had no patient with complete loss of the flap. Five patients (20%) had marginal necrosis of the flap and two patients have graft loss due to underlying hematoma and required secondary split thickness skin grafting. CONCLUSION The distally based peroneus brevis muscle flap is a safe option with reliable anatomy for small to moderate sized defects following low velocity injury around the ankle. The commonest complication encountered is skin graft loss which can be reduced by primary delayed grafting.
Adolescent ; Adult ; Aged ; Ankle Injuries ; surgery ; Child ; Child, Preschool ; Female ; Follow-Up Studies ; Humans ; Leg Injuries ; surgery ; Male ; Middle Aged ; Muscle, Skeletal ; Operative Time ; Retrospective Studies ; Surgical Flaps ; Tissue and Organ Harvesting ; Treatment Outcome ; Young Adult

BACKGROUND: Rhabdomyolysis is a syndrome caused by injury to skeletal muscle and characterized by myalgia and swelling of the affected muscles. Peripheral nerve injury rarely occurs in patients with rhabdomyolysis. METHODS: We reviewed the medical records of 8 consecutive patients with peripheral neuropathies associated with rhabdomyolysis. We assessed the clinical characteristics and electrodiagnostic findings of eight patients. RESULTS: In seven patients, rhabdomyolysis occurred after prolonged immobilization. In one patient, blunt trauma was a cause of rhabdomyolysis. All patients presented with weakness and paresthesia in lower extremities and electrodiagnostic tests showed peripheral nerve injury suggesting sciatic neuropathy or lumbosacral plexopathy. Although rhabdomyolysis itself recovered completely in all patients, neurologic deficits from neuropathy recovered partially and slowly. CONCLUSIONS: Sciatic nerve or lumbosacral plexus was injured in all eight patients. Among the various causes of rhabdomyolysis, prolonged immobilization is associated with development of peripheral neuropathy.
Electrodiagnosis ; Humans ; Immobilization ; Lower Extremity ; Lumbosacral Plexus ; Medical Records ; Muscle, Skeletal ; Muscles ; Myalgia ; Neurologic Manifestations ; Paresthesia ; Peripheral Nerve Injuries ; Peripheral Nervous System Diseases ; Rhabdomyolysis ; Sciatic Nerve ; Sciatic Neuropathy

PURPOSE: This study aimed to investigate effect of ankle instability on peripheral muscle activation among female ballet dancers to provide information on the development of prevention programs for ankle injury rehabilitation. METHODS: 32 female ballet dancers were randomly divided into two groups: experience ankle sprain group (n=16, age, 20.7±0.8years, BMI 18.6±1.2kg/m2) and non-experience ankle sprain group (n=16, age=21.0±0.8 years, BMI 19.6±2.0kg/m2). Activation of the peroneus longus, tibialis anterior muscle, and gastrocnemius during vertical landing, half pointe, and gait between the two groups were measured. Body composition analyzer was used to examine skeletal muscle mass and body fat mass. RESULTS: A total of 32 patients were included. In the experience ankle sprain group (n=16: left sprain 14, right sprain 2), average ankle sprain injury occurred 7.5 months before the study. The average age of the dancers in the experience ankle sprain group and non-experience ankle sprain group was 20.7±0.8 and 21.0±0.8years, major period was 64.5±23.8 and 71.6±25.8months, BMI was 18.6±1.2 and 19.5±2.0kg/m2, respectively. No significant differences were found on body composition between the two groups (p>0.05). The experience ankle sprain group showed significantly lower tibialis anterior and peroneus longus muscle activation (p<0.5), while gastrocnemius muscle activation appeared to be significantly higher (p<0.05) during landing, half pointe, and normal gait. CONCLUSION: Ankle sprain can cause a decline in peripheral muscle activation and coordination, which increased the risk for repetitive ankle sprain in the future. Moreover, ankle peripheral muscle selective strength training, coordination program development, and application need to be considered to prevent ankle sprain.
Adipose Tissue ; Ankle Injuries ; Ankle ; Body Composition ; Dancing ; Female ; Gait ; Humans ; Leg ; Muscle, Skeletal ; Muscles ; Program Development ; Rehabilitation ; Resistance Training ; Sprains and Strains

Objective To investigate the expression of cannabinoid type 2 receptor （CB2R） at different time points after brain contusion and its relationship with wound age of mice. Methods A mouse brain contusion model was established with PCI3000 Precision Cortical Impactor. Expression changes of CB2R around the injured area were detected with immunohistochemical staining, immunofluorescent staining and Western blotting at different time points. Results Immunohistochemical staining results showed that only a few cells in the cerebral cortex of the sham operated group had CB2R positive expression. The ratio of CB2R positive cells gradually increased after injury and reached the peak twice at 12 h and 7 d post-injury, followed by a decrease to the normal level 28 d post-injury. The results of Western blotting were consistent with the immunohistochemical staining results. Immunofluorescent staining demonstrated that the changes of the ratio of CB2R positive cells in neurons, CB2R positive cells in monocytes and CB2R positive cells in astrocytes to the total cell number showed a single peak pattern, which peaked at 12 h, 1 d and 7 d post-injury, respectively. Conclusion The expression of CB2R after brain contusion in neurons, monocytes and astrocytes in mice suggests that it is likely to be involved in the regulation of the biological functions of those cells. The changes in CB2R are time-dependent, which suggests its potential applicability as a biological indicator for wound age estimation of brain contusion in forensic practice.
Animals ; Blotting, Western ; Brain Contusion/metabolism* ; Brain Injuries ; Forensic Pathology ; Mice ; Muscle, Skeletal/pathology* ; Receptor, Cannabinoid, CB2/metabolism* ; Receptors, Cannabinoid ; Time Factors ; Wound Healing/physiology*

OBJECTIVESTo explore the possible biological mechanism of skeletal muscle contusion repair through researching the changes in expression of autophagy-related genes and proteins in SD rats with acute skeletal muscle contusion.

METHODSSix rats were randomly selected as the control group from 30 male SD rats, acute skeletal muscle contusion model were established in the remaining 24 rats with self-made hitter, then the model rats were randomly divided into 4 groups (3 d, 5 d, 7 d, 14 d groups, =6). On the 3, 5, 7 and 14 day after injury, injured gastrocnemius of each group was harvested. The morphological and the ultra-microstructure changes of gastrocnemius after injury were observed by HE staining and transmission electron microscope (TEM) respectively. The relative protein levels of (LC3-Ⅱ) and P62 of each group were observed by Western blot. The relative mRNA levels of atg7, atg10, atg12, atg16L1 of each group were observed by RTPCR.

RESULTSThe results of HE staining showed that compared with the control group, the inflammation reached its peak on the 5 day after injury, new muscle fibers were clearly observed in 7 d group. The results of TEM showed that, compared with the control group, oncotic mitochondria could be clearly seen in the 3 d, 5 d, 7 d groups. Also, the Z line changed from disappearing to drift thickening, sarcoplasmic reticulum dilatation gradually improved, there was no evident difference between the 14 d group and the control group, suggesting that the damage has preliminarily healed. The results of Western blot showed that the expressions of LC3-Ⅱand P62 were increased at first and then decreased. The expression of LC3-Ⅱwas markedly up-regulated in the 3 d, 5 d, 7 d groups compared with the control group and the 14 d group (<0.01). Similarly, compared with the control group, the expression of P62 reached its peak on the 3 day after injury (<0. 01), and returned to normal level on the 14 day. The results of RT-PCR showed that the expression of atg10 mRNA in the natural recovery group of 3 d, 5 d, 7 d, 14 d was firstly decreased and then increased, the atg10 mRNA was markedly down-regulated in the 3 d, 5 d, 7 d groups compared with the control group and the 14 d group (<0. 01). The expression of atg7, atg12, atg16L1 mRNA was generally increased at first and then decreased, it was markedly up-regulated in the 3 d, 5 d, 7 d groups compared with the control group and the 14 d group (<0.01, <0.05, <0.01).

CONCLUSIONSThe above results indicate that the autophagy is involved in repair of skeletal muscle injury by its autophagyrelated factors,regularly changes after contusion, and the rate of damage repair may be related to the level of autophagy.

Animals ; Autophagy ; Contusions ; physiopathology ; Male ; Muscle, Skeletal ; injuries ; RNA, Messenger ; Rats ; Rats, Sprague-Dawley