In order to realize the quantitative assessment of muscle strength in hand function rehabilitation and then formulate scientific and effective rehabilitation training strategies, this paper constructs a multi-scale convolutional neural network (MSCNN) - convolutional block attention module (CBAM) - bidirectional long short-term memory network (BiLSTM) muscle strength prediction model to fully explore the spatial and temporal features of the data and simultaneously suppress useless features, and finally achieve the improvement of the accuracy of the muscle strength prediction model. To verify the effectiveness of the model proposed in this paper, the model in this paper is compared with traditional models such as support vector machine (SVM), random forest (RF), convolutional neural network (CNN), CNN - squeeze excitation network (SENet), MSCNN-CBAM and MSCNN-BiLSTM, and the effect of muscle strength prediction by each model is investigated when the hand force application changes from 40% of the maximum voluntary contraction force (MVC) to 60% of the MVC. The research results show that as the hand force application increases, the effect of the muscle strength prediction model becomes worse. Then the ablation experiment is used to analyze the influence degree of each module on the muscle strength prediction result, and it is found that the CBAM module plays a key role in the model. Therefore, by using the model in this article, the accuracy of muscle strength prediction can be effectively improved, and the characteristics and laws of hand muscle activities can be deeply understood, providing assistance for further exploring the mechanism of hand functions .
Neural Networks, Computer ; Humans ; Hand Strength/physiology* ; Support Vector Machine ; Muscle Strength/physiology* ; Hand/physiology* ; Convolutional Neural Networks

Multimorbidity of chronic diseases is one of the most common health issues among older adults, and the resulting demand for long-term medical care and management imposes a considerable burden on healthcare systems. Muscle strength, a core indicator of overall health status, is closely associated with the risk of developing multimorbidity of chronic diseases in older adults. Decline in muscle strength not only increases the risk of multimorbidity of chronic diseases but also interacts with it to exacerbate disease burden. In older adults with existing multimorbidity of chronic diseases, muscle strength decline can impair physical function and quality of life, leading to a vicious cycle of disease progression and physical disability. Strength training can help prevent multimorbidity, with potential mechanisms including the promotion of anti-inflammatory effects and enhancement of mitochondrial energy metabolism. This review summarizes the impact of muscle strength decline on multimorbidity of chronic diseases in older adults and the effectiveness and potential mechanisms of exercise interventions, providing evidence to delay muscle strength decline, prevent the occurrence and progression of multimorbidity of chronic diseases, and improve quality of life in older adults.
Humans ; Aged ; Chronic Disease/prevention & control* ; Muscle Strength/physiology* ; Multimorbidity ; Quality of Life ; Resistance Training ; Exercise Therapy ; Exercise ; Sarcopenia

Objective To evaluate the effects of knee flexor and extensor strength on the subjective function and motor performance of knees after anterior cruciate ligament reconstruction. Methods A total of 53 patients who underwent anterior cruciate ligament reconstruction in the National Institute of Sports Medicine,General Administration of Sport of China from June 2015 to June 2021 and met the inclusion criteria were enrolled in this study.The patients were followed up time for at least 2 years.An isometric muscle strength test system was used to measure the strength of bilateral quadriceps and hamstring muscles.The patients were grouped according to whether the limb symmetry index (LSI) of peak torque of quadriceps and hamstring muscle reached 85% at an angular velocity of 60°/s.Specifically,26 patients were classified into group A (LSI≥85%) and 27 patients were classified into group B (LSI<85%).The subjective function and motor performance of knees were compared between the two groups. Results In terms of subjective function of knees,the international knee documentation committee (IKDC) score (88.76±9.93 vs. 81.08±12.57,P=0.017) and knee injury and osteoarthritis outcome score (KOOS) (86.27±8.96 vs. 80.22±11.31,P=0.036) were different between groups A and B.There was no significant difference in Lysholm score [95.0 (79.8,100.00) vs. 86.00 (66.00,100.00),P=0.238],ACL return to sports after injury scale score (66.08±22.25 vs. 61.12±23.53,P=0.434),Marx score [6.00 (4.75,7.00) vs. 6.00 (4.00,7.00),P=0.805] or Tegner activity score [8.00 (4.00,12.00) vs. 4.00 (2.00,12.00),P=0.566] between the two groups.In terms of motor performance,the single-leg triple hop LSI (0.92±0.13 vs. 0.81±0.18,P=0.016) and single-leg crossover hop LSI (0.96±0.12 vs. 0.84±0.22,P=0.021) showed significant differences between groups A and B,while there was no significant difference in single-leg hop LSI (0.90±0.18 vs. 0.79±0.25,P=0.116) between the two groups.In addition,there was no statistical significance in proprioception [30°:8.83±4.66 vs. 10.73±4.63,P=0.143;45°:6.94±3.82 vs. 7.66±3.93,P=0.504;60°:4.10 (3.20,4.72) vs. 3.90 (2.30,5.20),P=0.493] or Y-balance test results [anterior LSI:0.98 (0.84,1.02) vs. 0.94 (0.86,0.98),P=0.328;posterolateral LSI:1.00±0.08 vs. 0.97±0.07,P=0.249;posteromedial LSI:1.00 (0.97,1.03) vs. 0.96 (0.93,1.03),P=0.179] between groups A and B. Conclusion The patients with good symmetry of quadriceps and hamstring muscle strength after anterior cruciate ligament reconstruction had better subjective function and movement performance of knees than the patients with poor symmetry,which was mainly reflected in the IKDC score,KOOS,single-leg triple hop,and single-leg crossover hop.
Humans ; Anterior Cruciate Ligament Reconstruction ; Muscle Strength/physiology* ; Male ; Quadriceps Muscle/physiology* ; Female ; Adult ; Anterior Cruciate Ligament Injuries/physiopathology* ; Hamstring Muscles/physiopathology* ; Knee Joint/physiopathology* ; Anterior Cruciate Ligament/physiopathology* ; Torque ; Knee/physiopathology*

Iliotibial band syndrome (ITBS), as an overused injury of the lower extremities, has developed into a common cause of lateral knee pain. At present, the treatment of ITBS includes drug therapy, muscle strength training, physical therapy, and surgical treatment. Among these methods, physical therapy, drug therapy, and surgical treatment can only alleviate the symptoms of patients. As a safe and effective treatment, lower limb muscle strength training can improve patients' muscle strength, correct abnormal gait, and reduce the recurrence rate of the disease by paying attention to the dynamic changes of patients' recovery process. At present, the pathogenesis of ITBS remains unclear, and the treatment methods are not unified. It is necessary to further study the biomechanical factors related to the lower extremities and develop more scientific and comprehensive muscle strength training methods.
Humans ; Resistance Training ; Running/physiology* ; Iliotibial Band Syndrome/diagnosis* ; Lower Extremity ; Physical Therapy Modalities/adverse effects* ; Knee Joint ; Muscle Strength/physiology* ; Muscles/injuries* ; Biomechanical Phenomena

Objective: To investigate the present situation of pelvic floor muscle strength, and to analyze the factors affecting pelvic floor muscle strength. Methods: The data of patients who were admitted into the general outpatient department of gynecology, Peking University People's Hospital from October 2021 to April 2022 were collected, and the patients who met the exclusion criteria were included in this cross sectional study. The patient's age, height, weight, education level, defecation way and defecation time, birth history, maximum newborn birth weight, occupational physical activity, sedentary time, menopause, family history and disease history were recorded by questionnaire. Morphological indexes such as waist circumference, abdomen circumference and hip circumference were measured with tape measure. Handgrip strength level was measured with grip strength instrument. After performing routine gynecological examinations, the pelvic floor muscle strength was evaluated by palpation with modified Oxford grading scale (MOS). MOS grade>3 was taken as normal group and ≤3 as decreased group. Binary logistic regression was used to investigate the related factors of deceased pelvic floor muscle strength. Results: A total of 929 patients were included in the study, and the average MOS grade was 2.8±1.2. By univariate analysis, birth history, menopausal time, defecation time, handgrip strength level, waist circumference and abdominal circumference were related to the decrease of pelvic floor muscle strength (all P<0.05). By binary logistic regression analysis, the level of handgrip strength (OR=0.913, 95%CI: 0.883-0.945; P<0.001) was correlated with normal pelvic floor muscle strength; waist circumference (OR=1.025, 95%CI: 1.005-1.046; P=0.016), birth history (OR=2.224, 95%CI: 1.570-3.149; P<0.001), sedentary time> 8 hours (OR=2.073, 95%CI: 1.198-3.587; P=0.009) were associated with the decrease of pelvic floor muscle strength. Conclusions: The level of handgrip strength is related to the normal pelvic floor muscle strength of females, while the waist circumference, birth history and sedentary time>8 hours are related to the decrease of pelvic floor muscle strength of females. In order to prevent the decrease of pelvic floor muscle strength, it is necessary to carry out relevant health education, enhance exercise, improve the overall strength level, reduce daily sedentary time, maintain symmetry, and carry out comprehensive overall intervention to improve pelvic floor muscle function.
Adult ; Female ; Humans ; Cross-Sectional Studies ; Gynecology ; Hand Strength ; Muscle Contraction/physiology* ; Muscle Strength/physiology* ; Outpatients ; Pelvic Floor/physiology*

OBJECTIVE: To explore relationship between intramuscular fat content of quadriceps femoris and clinical severity of knee osteoarthritis (KOA). METHODS: Totally 30 KOA patients were selected from February 2021 to June 2021, including 6 males and 24 females, aged with an average of (64.20±9.19) years old, and body mass index (BMI) was (24.92±3.35) kg·m-2. Patients were divided into relative severe leg (RSL) and relative moderate leg (RML) according to severity of pain on visual analogue scale(VAS). Musculoskeletal ultrasound was used to collect muscle images of quadriceps muscles on both sides of the patient, and Image J was used to analyze echo intensity (EI) of each muscle. Both VAS and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) were used to assess pain and function. Quadriceps muscle EI on both sides of patients was compared. Pearson correlation analysis was conducted to analyze correlation between quadriceps muscle EI value between RSL and RML, and linear regression was used to analyze relationship between each muscle EI and VAS and WOMA scores of patients. RESULTS: The EI of RSL lateral vastus lateralis (VL) was 123.78±36.25 and RSL vastus medialis (VM) was 109.46±30.36 which were significantly higher than those of 108.03±31.34 and 93.32±26.04 of RML (P<0.05), but there was no statistical significance in EI values of rectus femoris (RF) on both sides (P>0.05). EI values of VL and VM on both sides were significantly correlated (P<0.05). There was a significant positive correlation between VM EI value and VAS score in RSL and RML (P<0.05). VM EI values in RSL were positively correlated with total WOMAC (P<0.05), and VM VL EI values in RML were positively correlated with total WOMAC score (P<0.05). CONCLUSION Intramuscular fat content of quadriceps is closely related to severity of clinical symptoms in KOA patients, and the most obvious one is VM. Therefore, the intramuscular fat content of quadriceps may be an objective indicator to evaluate severity of KOA patients. At the same time, reducing intramuscular fat content of the quadriceps muscle of KOA patients may be a new direction for the prevention and treatment of KOA.
Male ; Female ; Humans ; Aged ; Middle Aged ; Quadriceps Muscle/physiology* ; Osteoarthritis, Knee/diagnosis* ; Pain ; Body Mass Index ; Muscle Strength/physiology* ; Knee Joint

OBJECTIVE: To explore application value and effectiveness of virtual reality technology combined with isokinetic muscle strength training in the rehabilitation of patients after anterior cruciate ligament (ACL) reconstruction surgery. METHODS: Forty patients who underwent ACL reconstruction surgery from December 2021 to January 2023 were selected and divided into control group and observation group according to treatment methods, 20 patients in each group. Control group was received routine rehabilitation training combined with isokinetic muscle strength training, including 15 males and 5 females, aged from 17 to 44 years old, with an average of (29.10±8.60) years old. Observation group was performed virtual reality technology combined with isokinetic muscle strength training, including 16 males and 4 females, aged from 17 to 45 years old with an average of (30.95±9.11) years old. Lysholm knee joint score, knee extension peak torque, and knee flexion peak torque between two groups at 12 (before training) and 16 weeks (after training) after surgery were compared. RESULTS: All patients were followed up for 1 to 6 months with an average of (3.30±1.42) months. There were no statistically significant difference in Lysholm knee joint score, peak knee extension peak torque, and peak knee flexion peak torque between two groups (P>0.05) before training. After training, Lysholm knee joint score, knee extension peak torque, and knee flexion peak torque of both groups were improved compared to before training (P<0.05);there were significant difference in Lysholm knee joint score, knee extension peak torque, and knee flexion peak torque between two groups(P<0.05). CONCLUSION The application of virtual reality technology combined with isokinetic muscle strength training could promote recovery of knee joint function and enhance muscle strength in patients after ACL reconstruction surgery in further.
Male ; Female ; Humans ; Adolescent ; Young Adult ; Adult ; Middle Aged ; Anterior Cruciate Ligament Injuries/surgery* ; Resistance Training ; Knee Joint/surgery* ; Anterior Cruciate Ligament Reconstruction/methods* ; Knee Injuries/surgery* ; Muscle Strength/physiology*

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

OBJECTIVE: To evaluate the feasibility and safety of Liuzijue exercise (LE) for the clinical effect in patients after cardiac surgery. METHODS: Totally 120 patients who underwent cardiac surgery and were admitted to the Cardiothoracic Intensive Care Unit of Nanjing Drum Tower Hospital between July and Oclober, 2022 were allocated to the LE group, the conventional respiratory training (CRT) group, and the control group by a random number table at a ratio of 1:1:1; 40 patients in each group. All patients received routine treatment and cardiac rehabilitation. LE group and CRT group respectively performed LE and CRT once a day for 30 min for 7 days. Control group did not receive specialized respiratory training. The forced vital capacity, forced expiratory volume in 1 s, peak inspiratory flow rate, peak expiratory flow rate, maximum inspiratory pressure, maximum expiratory pressure, modified Barthel index (MBI), and Hamilton Rating Scale for Anxiety (HAM-A) were evaluated before, after 3 and 7 days of intervention. In addition, the postoperative length of hospital stay (LOS) and the adverse events that occurred during the intervention period were compared. RESULTS: A total of 107 patients completed the study, 120 patients were included in the analysis. After 3 days of intervention, the pulmonary function, respiratory muscle strength, MBI and HAM-A of all 3 groups improved compared with that before the intervention (P<0.05 or P<0.01). Compared with the control group, pulmonary function and respiratory muscle strength were significantly improved in the CRT and LE groups (P<0.05 or P<0.01). MBI and HAM-A were significantly improved in the LE group compared with the control and CRT groups (P<0.05 or P<0.01). On the 7th day after intervention, the difference was still statistically significant (P<0.01), and was significantly different from that on the 3rd day (P<0.05 or P<0.01). In addition, on the 7th day of intervention, the pulmonary function and respiratory muscle strength in the LE group were significantly improved compared with those in the CRT group (P<0.01). MBI and HAM-A were significantly improved in the CRT group compared with the control group (P<0.01). There were no significant differences in postoperative LOS among the 3 groups (P>0.05). No training-related adverse events occurred during the intervention period. CONCLUSIONS LE is safe and feasible for improving pulmonary function, respiratory muscle strength, the ability to complete activities of daily living and for relieving anxiety of patients after cardiac surgery (Registration No. ChiCTR2200062964).
Humans ; Activities of Daily Living ; Breathing Exercises ; Cardiac Surgical Procedures/adverse effects* ; Respiratory Muscles ; Muscle Strength/physiology*

Objective: To evaluate the effects of exercise intervention on musculoskeletal disorders (MSD) in nursing staff. Methods: In september 2021, we searched the articles on exercise intervention for nurses with musculoskeletal diseases in Embase, PubMed, ClinicalTrails, Wanfang, CNKI and other databases in September 2021, and the search period was from database creation to August 2021. The quality of article was evaluated by Cochrane bias risk assessment tool and MINORS. The systematic review method with narrative synthesis was used to analyze the research results. Results: A total of 7 studies were included, including 6 randomized controlled trials and 1 quasi-experiment. The sample size of the experimental group was 276, and the control group was 273. Depending on the type of exercise intervention, muscle strength training, muscle strength training+stretch/flexibility training, Back School program can reduce the local pain of nursing staff. Among them, muscle strength training can improve the nursing staff's muscle function and quality of life, muscle strength training+stretching/flexibility training can increase muscle strength, range of physical activity and self-efficacy, the Back School program is effective for improving poor posture. Conclusion: Exercise intervention is effective on controlling musculoskeletal disorder symptoms in nursing staff, managers can develop exercise strategies for different MSD symptoms.
Exercise Therapy/methods* ; Humans ; Muscle Strength/physiology* ; Musculoskeletal Diseases ; Nursing Staff ; Quality of Life