Clinical trials have demonstrated that kilohertz-frequency transcutaneous spinal cord stimulation (TSCS) can be used to facilitate the recovery of sensory-motor function for patients with spinal cord injury, whereas the neural mechanism of TSCS is still undetermined so that the choice of stimulation parameters is largely dependent on the clinical experience. In this paper, a finite element model of transcutaneous spinal cord stimulation was used to calculate the electric field distribution of human spinal cord segments T ₁₂ to L ₂, whereas the activation thresholds of spinal fibers were determined by using a double-cable neuron model. Then the variation of activation thresholds was obtained by varying the carrier waveform, the interphase delay, the modulating frequency, and the modulating pulse width. Compared with the sinusoidal carrier, the usage of square carrier could significantly reduce the activation threshold of dorsal root (DR) fibers. Moreover, the variation of activation thresholds was no more than 1 V due to the varied modulating frequency and decreases with the increased modulating pulse width. For a square carrier at 10 kHz modulated by rectangular pulse with the frequency of 50 Hz and the pulse width of 1 ms, the lowest activation thresholds of DR fibers and dorsal column fibers were 27.6 V and 55.8 V, respectively. An interphase delay of 5 μs was able to reduce the activation thresholds of the DR fibers to 20.1 V. The simulation results can lay a theoretical foundation on the selection of TSCS parameters in clinical trials.
Humans ; Spinal Cord Stimulation/methods* ; Nerve Fibers/physiology* ; Finite Element Analysis ; Spinal Cord/physiology* ; Computer Simulation ; Spinal Cord Injuries/physiopathology* ; Lumbosacral Region ; Lumbar Vertebrae ; Transcutaneous Electric Nerve Stimulation/methods* ; Models, Neurological

BACKGROUND: There is a gap in understanding the effects of different acupoints and treatment methods (acupuncture and moxibustion) on microcirculatory changes in the lumbar region. OBJECTIVE: This study aimed to assess the thermal effects of acupuncture at Weizhong (BL40), with acupuncture at Chize (LU5) and moxibustion at both acupoints as control interventions. DESIGN, SETTING, PARTICIPANTS AND INTERVENTIONS: In this randomized controlled trial, 140 healthy participants were equally divided into four groups: acupuncture at BL40 (Acu-BL40), acupuncture at LU5 (Acu-LU5), moxibustion at BL40 (Mox-BL40) and moxibustion at LU5 (Mox-LU5). Participants underwent a 30-minute session of their assigned treatment. Infrared thermal imaging was used to collect temperature data on the areas of interest for analysis. MAIN OUTCOME MEASURES: The primary measure was the change in average temperature of the observed area after the intervention. The secondary measures included periodic temperature changes every 5 min and the temperature changes of the Governor Vessel and Bladder Meridian in the observed area after the intervention. RESULTS: Significant interactions were observed between treatments and acupoints affecting temperature (P < 0.001). The Acu-BL40 group showed a notably higher increase in mean temperature after 30 min compared to the Acu-LU5 and Mox-BL40 groups, with increases of 0.29 (95% confidence interval [CI] = 0.17 to 0.41) and 0.24 (95% CI = 0.08 to 0.41) °C, respectively. CONCLUSION: Acupuncture at BL40 acupoint can significantly increase the mean temperature in the observed area, highlighting the specific thermal effect of acupuncture compared to moxibustion in the lumbar area. This suggests a potential therapeutic benefit of acupuncture at BL40 for managing lumbar conditions. TRIAL REGISTRATION ClinicalTrials.gov (NCT05665426). Please cite this article as: Zheng SY, Wang XY, Lin LN, Liu S, Huang XX, Liu YY, Yu XS, Pan W, Fang JQ, Liang Y. Lumbar temperature change after acupuncture or moxibustion at Weizhong (BL40) or Chize (LU5) in healthy adults: A randomized controlled trial. J Integr Med. 2025; 23(2): 145-151.
Adult ; Female ; Humans ; Male ; Young Adult ; Acupuncture Points ; Acupuncture Therapy ; Body Temperature ; Healthy Volunteers ; Lumbosacral Region/physiology* ; Moxibustion ; Adolescent

OBJECTIVETo investigate the correlation between the lumbar bone marrow fat and abdominal fat.

METHODSA total of 68 individuals (32 men and 36 women, aged 21-74 years with a median of 49.5 years) were included in this study. All the subjects underwent spectroscopic examination of the third lumber vertebra with the single voxel method on a 1.5T MR scanner to measure the fat fraction (FF%). Quantitative CT was also performed for measurement of the abdomen subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT). The measurements were compared between subjects aged ≥50 years and those below 50 years, respectively,in male or female subjects.

RESULTSIn male subjects, BMI, FF%, VAT or SAT showed no significant differences between the two age groups (P>0.05), and FF% was not correlated with BMI, VAT or SAT (r=0.109, 0.034, 0.066, respectively; P>0.05). In the female subjects, BMI, FF%, VAT and SAT differed significantly between the two age groups (P<0.05), and in ≥50 years group, FF% showed a positive correlation with VAT (r=0.499, P<0.05) but was not correlated with SAT (r=0.221, P>0.05); in<50 years group, FF% was not correlated with VAT or SAT (r=0.076, -0.067, respectively; P>0.05).

CONCLUSIONFF% is positively correlated with VAT in female subjects aged beyond 50 years, but is not correlated with VAT or SAT in male subjects or in younger female subjects.

Adiposity ; Adult ; Aged ; Bone Marrow ; physiology ; Female ; Humans ; Intra-Abdominal Fat ; physiology ; Lumbosacral Region ; Male ; Middle Aged ; Prospective Studies ; Spine ; Subcutaneous Fat, Abdominal ; physiology ; Young Adult

OBJECTIVETo investigate the effect of exercise load on apparent diffusion coefficient (ADC) and fractional anisotropy (FA) of normal lumbar intervertebral discs in magnetic resonance (MR) diffusion tensor imaging (DTI).

METHODSThirty healthy volunteers (24 males and 6 females, aged 19 to 25 years) underwent examinations with MR T2WI and DTI of the lumbar intervertebral discs before and after exercise load. Pfirrmann grading was evaluated with T2WI, and the B0 map, ADC map and FA map were reconstructed based on the DTI data to investigate the changes in ADC and FA after exercise.

RESULTSOf the 30 volunteers (150 intervertebral discs) receiving the examination, 27 with discs of Pfirrminn grade II were included for analysis. In these 27 volunteers, the average ADC and FA before exercise were (1.99 ± 0.18)×10⁻³ mm²/s and 0.155∓0.059, respectively. After exercise, ADC was lowered significantly to (1.93 ± 0.17)×10⁻³ mm²/s (P<0.05) and FA increased slightly to 0.1623 ± 0.017 (P>0.05).

CONCLUSIONDTI allows quantitatively analysis of the changes in water molecular diffusion and anisotropy of the lumbar intervertebral discs after exercise load, which can cause a decreased ADC and a increased FA value, and the change of ADC is more sensitive to exercise load.

Adult ; Anisotropy ; Diffusion Magnetic Resonance Imaging ; Diffusion Tensor Imaging ; Exercise ; Female ; Humans ; Intervertebral Disc ; physiology ; Lumbosacral Region ; physiology ; Male ; Reference Values ; Young Adult

OBJECTIVETo investigate the relationship between backrest thickness and lumbar muscle fatigue so as to confirm the fitting backrest thickness.

METHODTwenty subjects coming from university seated at a computer workstation in three backrest thicknesses: 4, 7 and 10 cm. The time that the subjects reported the lumbar muscle fatigue was collected during each trial and subjective appraise was collected at the end of the entire protocol.

RESULTSThe MF value decreased and lumbar muscle felt fatigue in all three backrest thickness. Subject could feel fatigue more late [(45.0 +/- 10.8) min] and subject felt more comfort at 7 cm thickness.

CONCLUSIONIt is better to relive computer worker lumbar muscle fatigue when the backrest thickness was kept on 7 cm. Work break was needed because one hour work could cause muscle fatigue.

Adult ; Female ; Humans ; Lumbosacral Region ; Male ; Muscle Fatigue ; Muscle, Skeletal ; physiology ; Occupational Health ; Posture ; Sprains and Strains ; etiology ; prevention & control ; Young Adult

OBJECTIVETo investigate the recovery duration of manual lifting tasks.

METHODS30 college student volunteers with gender equally distributed were involved in the simulated stoop-, squart- and semi squart-lifting tasks in the laboratory. Signals of electromyography (EMG) at the back muscles (left and right thorax m. erector spinae, LT(10) and RT(10); left and right lumbar m. erector spinae, LL(3) and RL(3)) and electrocardiography (ECG) were recorded during the rest intervals. The percentage of maximum voluntary electrical activation (MVE%), EMG median frequency (MF), and heart rate (HR) were analyzed to predict the recovery time required.

RESULTSDuring the break, MVE% at 4 back muscles of all the male subjects were recovered to resting level within 5 minutes and 91.8% were within 2 minutes. Except for RL(3) after squat- and stoop-lifting task, the MVE% of female subjects went back to resting level within 3 minutes and 67.8% were within 2 minutes. The MF of male subjects were recovered in 10 minutes and 74.9% within 2 minutes, with the exception of RL(3) after stoop- and squat-lifting tasks. All the female MF were recovered in 8 minutes and 83.4% were within 2 minutes. However, during the last 20 minute break after the lifting tasks, the MVE% and MF of all male and female subjects were recovered, while HR came back to resting level within 14 and 5 minutes, respectively.

CONCLUSIONSFor the three manual lifting tasks with 25% MVC workload lasting for 4.5 min, a break of 15 minutes is sufficient for most erectors spinae to recover from local muscle load. However, in terms of the HR, a break of 15 minutes is enough for the recovery of systematic load.

Adult ; Back ; Electrocardiography ; Electromyography ; Female ; Humans ; Lifting ; Lumbosacral Region ; Male ; Muscle, Skeletal ; physiology ; Posture ; Rest ; physiology ; Weight-Bearing ; Young Adult

OBJECTIVETo study training effect of upper limbs and lumbar muscles in the proceed of air striking of straight punch by analyzing boxing athletes' changes of electromyogram (EMG).

METHODSWe measured EMG of ten women boxing athletes' upper arm biceps (contractor muscle), upper arm triceps (antagonistic muscle), forearm flexor muscle (contractor muscle), forearm extensor muscle (antagonistic muscle), and lumbar muscles by ME6000 (Mega Electronics Ltd.). The stipulated exercise was to do air striking of straight punch with loads of 2.5 kg of dumbbell in the hand until exhausted.

RESULTSIn the proceed of exercise-induce exhausted, the descend magnitude and speed of median frequency (MF) in upper limb antagonistic muscle exceeded to contracting muscle, moreover, the work percentage showed that contractor have done a larger percentage of work than antagonistic muscle. Compared with world champion's EMG, the majority of ordinary athletes' lumbar muscles MF revealed non-drop tendency, and the work percentage showed that lumbar muscles had a very little percentage of work.

CONCLUSIONAfter comparing the EMG test index in upper limb and lumbar muscle of average boxing athletes with that of the world champion, we find the testees lack of the training of upper limb antagonistic muscle and lumbar muscle, and more trainings aimed at these muscles need to be taken.

Boxing ; physiology ; Electromyography ; Female ; Humans ; Lumbosacral Region ; physiology ; Muscle, Skeletal ; physiology ; Physical Endurance ; physiology ; Resistance Training ; methods ; Upper Extremity ; physiology ; Young Adult

Biomechanical Phenomena ; Humans ; Lumbosacral Region ; physiology ; Male ; Occupational Health ; Wood ; Workplace

OBJECTIVE: To examine the influence of exogenous fat (lard) on the bone mineral density (BMD) of lumbar spine measured by dual energy X-ray absorptiometer (DXA) Hologic QDR 4500A in different sites in healthy women. METHODS: Lard packets (5 cm or 10 cm thick) were prepared. The lumbar spine (LS) DXA scans were performed on 37 women(Group A), who were repeated with lard packets (5 cm or 10 cm thick) placed over the abdomen, and the hip DXA scans were performed on 18 women(Group B), who were repeated with lard packets (5 cm or 10 cm thick) placed over the left thigh. Whole body DXA scans were performed on 8 women(Group C), who were repeated with 5 cm thick lard packets over the abdomen. The pair t-test was used to compare the value of BMD with and without lard. RESULTS: After lard was placed over abdomen, the bone area (BA), bone mineral content (BMC), and BMD of the LS decreased significantly (P<0.001);at the hip, BA had no significant change, but the BMC and BMD of the neck, trochanter, and inter trochanter increased significantly (P<0.01~0.05). The BMD of the whole body had no significant change (P>0.05). CONCLUSION Lard impacted the BMD by DXA Hologic QDR 4500A, BMD of the LS significantly decreases, but BMD of the whole body has no significant change. BMD of the hip significantly increases with lard.
Absorptiometry, Photon ; Adiposity ; physiology ; Adult ; Aged ; Bone Density ; Female ; Humans ; Lumbosacral Region ; diagnostic imaging ; Middle Aged ; Phantoms, Imaging

Adult ; Back ; physiology ; Electromyography ; Humans ; Lumbosacral Region ; physiology ; Male ; Muscle Fatigue ; Muscle, Skeletal ; physiology ; Posture ; physiology