Objective To investigate the mediating effect of phase angle between muscle strength and muscle function in maintenance hemodialysis (MHD) patients, aiming to provide a reference basis for clinical improvement of muscle strength and muscle function in MHD patients. Methods Random sampling was used to collect patients undergoing outpatient MHD in the Wenjiang Hemodialysis Room of the Department of Nephrology, West China Hospital, Sichuan University between September and December 2023 as the subjects of this study. Muscle strength was assessed by handgrip strength, muscle function was assessed by Short Physical Performance Battery (SPPB), and phase angle was measured by bioelectrical impedance analysis. The mediating effect of phase angle between muscle strength and muscle function was analyzed. Results A total of 239 MHD patients were included, including 125 males (52.3%) and 114 females (47.7%). The mean phase angle of MHD patients was (5.77±1.17)°, 89 patients (37.2%) showed decreased muscle strength, and 109 patients (45.6%) showed muscle hypoplasia. Spearman’s correlation analyses showed that phase angle was significantly and positively correlated with both handgrip strength and SPPB in MHD patients (P<0.001). The results of mediation effect analysis showed that handgrip strength was able to positively predict phase angle (β=0.535, P<0.001); handgrip strength was able to positively predict SPPB (β=0.481, P<0.001); phase angle was able to positively predict SPPB (β=0.296, P<0.001); and when both handgrip strength and phase angle entered in the regression equation, both handgrip strength (β=0.392, P<0.001) and phase angle (β=0.165, P<0.05) could positively predict SPPB. Phase angle in MHD patients partially mediated the association between muscle strength and muscle function, with the mediating effect accounting for 32.5% of the total effect. Conclusions There is a close relationship between phase angle, muscle strength and muscle function in MHD patients, and muscle strength can affect muscle function directly or indirectly through phase angle. Medical professionals should pay attention to the muscle function of MHD patients and further improve their muscle function by improving their phase angle and muscle strength.
ObjectiveTo systematically review the dose-effect relationship between resistance exercise intervention and lower extremity muscle strength and function enhancement in the aging. MethodsEBSCO, PubMed, Web of Science, CNKI, VIP, and WanFang Data databases were electronically searched to collect randomized controlled trials (RCTs) on the effects of resistance exercise on muscle strength and function of the lower extremities in older adults from inception to July 2022. Two reviewers independently screened literature, extracted data and assessed the risk of bias of the included studies. A network meta-analysis was then performed by using RevMan 5.4 and Stata 15.0 software. ResultsA total of 32 RCTs with a total sample size of 1 594 individuals were included. The results of network meta-analysis showed that the elements of resistance exercise prescription: intensity 50%-70% 1RM, period 8-12 weeks, frequency 3-4 times/week, duration 30-45 min, and intervals 1.1-2 min were superior to other doses. ConclusionThe optimal dose of resistance exercise for improving lower extremity muscle strength and function in older adults is moderate exercise intensity (50%-70% 1RM) for 8-12 weeks, 3-4 times per week, 30-45 min per exercise, and 1.1-2 min interval between sets.
The development of muscle strength evaluating system based on Android system was developed in this research. The system consists of a lower unit and an intelligent mobile terminal. The pressure sensor of the lower unit was used to collect muscle strength parameters. And the parameters were sent to the Android device through the wireless Bluetooth serial port. Then the Android device would send the parameters to the doctor monitored platform through the Internet. The system realized analyzing the muscle strength parameters and real-time displaying them. After it ran on the Android mobile phones, it showed an effective result which proved that the system combined with mobile platform could make more convenient for the patients to assess their own muscle strength. It also provided reliable data references for doctors to know the patients' rehabilitation condition and to make the next rehabilitation plan.
Objective To investigate the effect of preoperative lower-limb muscle strength on perioperative blood loss, postoperative pain, and functional recovery in patients undergoing total knee arthroplasty (TKA).Methods A retrospective analysis was conducted on the clinical data of 380 patients who underwent TKA and met the selection criteria between February 2023 and December 2024. Based on the gender-specific median of standardized preoperative lower-limb extensor isokinetic muscle strength (IMS), the patients were divided into a low-extensor strength group and a high-extensor strength group, with 190 cases in each group. The following data of the two groups were collected and compared, including age, gender, body mass index, comorbidities, surgical side, length of hospital stay, Kellgren-Lawrence grade, perioperative parameters [including hematocrit (Hct) and hemoglobin (Hb) levels within 1 week preoperatively and 2-3 days postoperatively, with the calculation of Hct loss and Hb loss (the difference between the pre- and post-operative measurements), and whether intraoperative allogeneic blood transfusion was performed], preoperative knee flexion and extension IMS, 5-time sit-to-stand (5-STS) test within 2 weeks preoperatively, as well as visual analogue scale (VAS) score for pain and active range of motion (AROM) within 2 weeks preoperatively and 1 day postoperatively. Pearson correlation analysis was used to analyze the correlation between preoperative lower-limb extensor IMS and TBL. Through multiple linear regression analysis, the effect of IMS on TBL was further explored after adjusting for confounding factors such as age, body mass index, hypertension, diabetes mellitus, coronary atherosclerotic heart disease, and chronic obstructive pulmonary disease. Results There was no significant difference between the two groups in age, gender, body mass index, surgical side, Kellgren-Lawrence grade, comorbidities, length of hospital stay, preoperative Hct and Hb levels, intraoperative allogeneic blood transfusion rate, and changes in VAS scores (P>0.05). The high-extensor strength group was superior to the low-extensor strength group in preoperative VAS scores, AROM, 5-STS, as well as postoperative Hct and Hb loss, and the changes of AROM and TBL were less than those in the low-extensor strength group, with all differences being significant (P<0.05). Pearson correlation analysis showed a negative correlation between preoperative lower-limb extensor IMS and TBL (r=–0.460, P=0.043). Multiple linear regression analysis showed that after adjustment, a lower TBL was associated with a higher preoperative lower-limb extensor IMS. Specifically, for every 1 N·m increase in preoperative lower-limb extensor IMS, TBL decreased by 9.973 mL. TBL was not significantly affected by other factors such as age, body mass index, and comorbidities. Conclusion Higher preoperative lower-limb muscle strength is associated with reduced intraoperative blood loss during TKA and improved postoperative pain relief and functional recovery. These findings highlight the critical role of preoperative muscle strength management, providing scientific evidence for designing standardized postoperative rehabilitation protocols and offering guidance for optimizing surgical timing to maximize recovery outcomes.
Objective To investigate the early effectiveness of fixed-bearing unicompartmental knee arthroplasty (FBUKA) in patients with anterior cruciate ligament deficiency (ACLD), and to evaluate postoperative muscle strength and functional recovery through isokinetic muscle strength testing. Methods A retrospective analysis was performed on the clinical data of 181 patients with unilateral medial compartment knee osteoarthritis who underwent FBUKA treatment between January 2023 and June 2024 and met the selection criteria. According to the integrity of the anterior cruciate ligament, the patients were divided into the ACLD group (45 cases) and the anterior cruciate ligament intact (ACLI) group (136 cases). There was no significant difference in baseline data between the two groups (P>0.05), including age, gender, body mass index, affected side, disease duration, and preoperative Hospital for Special Surgery (HSS) score, Lysholm score, and visual analogue scale (VAS) score. A standardized rehabilitation protocol was adopted after surgery. Isokinetic muscle strength parameters [peak torque (PT) and total work (TW) of quadriceps and hamstring, and hamstring-to-quadriceps ratio (H/Q) at angular velocities of 60°/s and 180°/s] and HSS score, Lysholm score, and VAS score were measured preoperatively and at 6 weeks, 3 months, 6 months, and 12 months after operation; posterior tibial slope (PTS) was measured at 12 months after operation. Results All patients were followed up 12-18 months, with a mean of 13.6 months. No complication such as aseptic loosening of the prosthesis, dislocation of the mobile bearing insert, infection, or revision occurred after operation. Isokinetic muscle strength testing showed that at angular velocities of 60°/s and 180°/s, the PT and TW of quadriceps and hamstring significantly decreased and H/Q increased in both groups at 6 weeks after operation when compared with preoperative values (P<0.05); then PT and TW increased gradually, and H/Q decreased gradually. Except for no significant difference at 3 months after operation compared with preoperative values (P>0.05), all indicators were significantly different from preoperative values at 6 and 12 months after operation (P<0.05). There was no significant difference in isokinetic muscle strength parameters between the two groups at any time point before and after operation (P>0.05). The HSS score, Lysholm score, and VAS score at each postoperative time point in both groups significantly improved when compared with preoperative values (P<0.05), and there was no significant difference in each score between the two groups at each postoperative time point (P>0.05). At 12 months after operation, the PTS in the ACLD group was significantly smaller than that in the ACLI group (P<0.05). Conclusion For ACLD patients without anteroposterior knee instability, the isokinetic muscle strength recovery trajectory and clinical functional scores after FBUKA are comparable to those of ACLI patients. For such patients, FBUKA can achieve satisfactory muscle strength and functional recovery, and isokinetic muscle strength testing can provide objective quantitative evidence for postoperative rehabilitation evaluation.
