Whole Body Muscle Activity During Weightlifting Exercise Evaluated By Positron Emission Tomography

Background: This study investigated the whole-body skeletal muscle activity pattern of hang power clean (HPC), a major weight training exercise, using positron emission tomography (PET). Methods: Twelve college weightlifting athletes performed three sets of HPC 20 times with a barbell set to 40 kg both before and after an intravenous injection of 37 MBq 18F-fluorodeoxyglucose (FDG). PET-computed tomography images were obtained 50 min after FDG injection. Regions of interest were defined within 71 muscles. The standardized uptake value was calculated to examine the FDG uptake of muscle tissue per unit volume, and FDG accumulation was compared to the control group. The Mann–Whitney U-test was used to evaluate the differences in the mean SUV between groups. The difference between SUVs of the right and left muscles was evaluated by a paired t-test. A P-value <0.05 was considered statistically significant.Results: FDG accumulation within the vastus lateralis, vastus intermedius, and vastus medialis was higher than that of the rectus femoris. FDG accumulation within the triceps surae muscle was significantly higher only in the soleus. In the trunk and hip muscles, FDG accumulation of only the erector spinae was significantly increased. In all skeletal muscles, there was no difference between SUVs of the right and left muscles.Conclusions: The monoarticular muscles in the lower limbs were active in HPC. In contrast, deep muscles in the trunk and hip were not active during HPC. HPC is not suitable for core training and needs to be supplemented with other training.

Is lumbar erector spinae plane block (L-ESPB) a lumbar plexus block?: a case report of three cases

Background Lumbar erector spinae plane block (L-ESPB) is being used in fractured hip patients for the postoperative pain relief and as a sole anesthetic technique. Various clinical and cadaveric studies have differences of opinion about its mechanism of action and pathways of local anesthetic spread; however, the role of lumbar plexus (LP) in the mechanism of action is still not considered. In our clinical experience, we observed that the action on LP could be a pathway for the analgesic action of local anesthetic along with paravertebral spread. Case presentation We report here three cases of the fractured hip who were given L-ESPB for postoperative pain management. The radiological examination was done after injection of non-ionic contrast to know the spread of local anesthetic. In two cases, the contrast spread was seen towards LP and in one case spread of contrast was observed towards the paravertebral area. Conclusions Effect of local anesthetic on the lumbar plexus is one of the plausible pathways in L-ESPB for its analgesic mechanism of action.

Validation for measurements of skeletal muscle areas using low-dose chest computed tomography

Various methods were suggested to measure skeletal muscle areas (SMAs) using chest low-dose computed tomography (chest LDCT) as a substitute for SMA at 3rd lumbar vertebra level (L3-SMA). In this study, four SMAs (L1-SMA, T12-erector spinae muscle areas, chest wall muscle area at carina level, pectoralis muscle area at aortic arch level) were segmented semi-automatically in 780 individuals taking concurrent chest and abdomen LDCT for healthcare screening. Four SMAs were compared to L3-SMA and annual changes were calculated from individuals with multiple examinations (n = 101). Skeletal muscle index (SMI; SMA/height2) cut-off for sarcopenia was determined by lower 5th percentile of young individuals (age ≤ 40 years). L1-SMA showed the greatest correlation to L3-SMA (men, R2 = 0.7920; women, R2 = 0.7396), and the smallest annual changes (0.3300 ± 4.7365%) among four SMAs. L1-SMI cut-offs for determining sarcopenia were 39.2cm2/m2 in men, and 27.5cm2/m2 in women. Forty-six men (9.5%) and ten women (3.4%) were found to have sarcopenia using L1-SMI cut-offs. In conclusion, L1-SMA could be a reasonable substitute for L3-SMA in chest LDCT. Suggested L1-SMI cut-offs for sarcopenia were 39.2cm2/m2 for men and 27.5cm2/m2 for women in Asian.

Different degeneration patterns of paraspinal muscles in degenerative lumbar diseases: a MRI analysis of 154 patients

Study design A retrospective study. Objective To evaluate the different degeneration patterns of paraspinal muscles in degenerative lumbar diseases and their correlation with lumbar spine degeneration severity. Summary of background data The degeneration characteristics of different paraspinal muscles in degenerative lumbar diseases remain unclear. Methods 78 patients diagnosed with single-level degenerative lumbar spondylolisthesis (DLS) and 76 patients with degenerative lumbar kyphosis (DLK) were included as DLS and DLK groups. Paraspinal muscle parameters of psoas major (PS), erector spinae (ES) and multifidus muscle (MF) were measured, including fatty infiltration (FI) and relative cross-sectional area (rCSA), namely the ratio of the paraspinal muscle CSA to the CSA of the vertebrae of the same segment. Sagittal parameters including lumbar lordosis (LL) and sagittal vertical axis (SVA) were measured. The paraspinal muscle parameters and ES/MF rCSA ratio were compared between the two groups. Paraspinal muscles parameters including rCSA and FI were also compared between each segments from L1 to L5 in both DLS and DLK groups. In order to determine the influence of sagittal spinal alignment on paraspinal muscle parameters, correlation analysis was conducted between the MF, ES, PS rCSA and FI and the LL in DLS and DLK group. Result MF atrophy is more significant in DLS patients compared with DLK. Also, MF fatty infiltration in the lower lumbar spine of DLS patients was greater compared to DLK patients. DLK patients showed more significant atrophy of ES and heavier ES fatty infiltration. MF FI was significantly different between all adjacent segments in both DLS and DLK groups. In DLS group, ES FI was significantly different between L2/L3 to L3/L4 and L4/L5 to L5/S1, while in DLK group, the difference of ES FI between all adjacent segments was not significant, and ES FI was found negatively correlated with LL. Conclusions Paraspinal muscles show different degeneration patterns in degenerative lumbar diseases. MF degeneration is segmental in both DLS and DLK patients, while ES degenerated diffusely in DLK patients and correlated with the severity of kyphosis. MF degeneration is more significant in the DLS group, while ES degeneration is more significant in DLK patients. MF is the stabilizer of the lumbar spine segments, while the ES tends to maintain the spinal sagittal balance.