In children with spinal cord injury (SCI), scoliosis due to trunk muscle paralysis frequently requires surgical treatment. Transcutaneous spinal stimulation enables trunk stability in adults with SCI ...and may pose a non-invasive preventative therapeutic alternative. This non-randomized, non-blinded pilot clinical trial (NCT03975634) determined the safety and efficacy of transcutaneous spinal stimulation to enable upright sitting posture in 8 children with trunk control impairment due to acquired SCI using within-subject repeated measures study design. Primary safety and efficacy outcomes (pain, hemodynamics stability, skin irritation, trunk kinematics) and secondary outcomes (center of pressure displacement, compliance rate) were assessed within the pre-specified endpoints. One participant did not complete the study due to pain with stimulation on the first day. One episode of autonomic dysreflexia during stimulation was recorded. Following hemodynamic normalization, the participant completed the study. Overall, spinal stimulation was well-tolerated and enabled upright sitting posture in 7 out of the 8 participants.
Walking requires active control of frontal plane balance through adjustments to mediolateral foot placement and ground reaction forces. Previous work on mediolateral balance perturbations and control ...of foot placement has often focused on the bilateral gluteus medius muscles. However, additional leg and trunk muscles can influence foot placement by transferring power to the foot and pelvis during swing. Thus, the purpose of this study was to determine individual muscle contributions to balance control following medial and lateral foot placement perturbations. Ten participants performed treadmill walking trials which included perturbations immediately before randomized heel strikes. Muscle contributions to foot placement, ground reaction forces, trunk power and frontal plane external moments during representative perturbed and unperturbed gait cycles were estimated using musculoskeletal modeling and simulation. Net muscle contributions to foot placement were 61 ± 50% more medial during the first recovery step following lateral perturbations and 28 ± 14% less medial in the second recovery step following medial perturbations. Following lateral perturbations, the swing gluteus medius performed 57 ± 50% more lateral work and the stance gluteus medius performed 61 ± 50% more medial work on the foot. Following medial perturbations, the erector spinae performed 39 ± 33% less lateral work on the foot. Changes in net muscle work on the foot were inconsistent with changes in step width, suggesting that changes in step width were not due to active muscle control but rather the mechanical effect of the perturbation. These outcomes provide a foundation for future studies analyzing balance control in populations at risk of falling.
This study investigated the effects of carrying a backpack while walking. Critical changes featuring the disproportionality of increases in trunk muscle activation and lumbar joint loading between ...light and heavy backpack carriage weight may reveal the load-bearing strategy (LBS) of the lumbar spine. This was investigated using an integrated system equipped with a motion analysis, a force platform and a wireless surface electromyography (EMG) system to measure the trunk muscle EMG amplitudes and lumbar joint component forces. A predictive goal programming model was developed to determine the most critical changes in trunk muscle activation and lumbar joint loading. Results suggested that lightweight backpack carriage at approximately 3% of body weight (BW) might reduce the peak lumbosacral compression force by 3% during walking compared with no load condition. The most critical changes in both trunk muscle activation and lumbosacral joint loading were found at a backpack load of 10% of BW.
Practitioner Summary: This study investigated the effects of backpack load on the LBS of lumbar spine while walking. A backpack load of 3% of BW might reduce the peak lumbosacral compression force by 3 and 10% of BW induced the most critical changes in LBS of lumbar spine.
Physical inactivity due to cachexia and muscle wasting is well recognized as a sign of poor prognosis in chronic obstructive pulmonary disease (COPD). However, there have been no reports on the ...relationship between trunk muscle measurements and energy expenditure parameters, such as the total energy expenditure (TEE) and physical activity level (PAL), in COPD. In this study, we investigated the associations of computed tomography (CT)-derived muscle area and density measurements with clinical parameters, including TEE and PAL, in patients with or at risk for COPD, and examined whether these muscle measurements serve as an indicator of TEE and PAL.
The study population consisted of 36 male patients with (n = 28, stage 1-4) and at risk for (n = 8) COPD aged over 50 years. TEE was measured by the doubly labeled water method, and PAL was calculated as the TEE/basal metabolic rate estimated by the indirect method. The cross-sectional areas and densities of the pectoralis muscles, rectus abdominis muscles, and erector spinae muscles were measured. We evaluated the relationship between these muscle measurements and clinical outcomes, including body composition, lung function, muscle strength, TEE, and PAL.
All the muscle areas were significantly associated with TEE, severity of emphysema, and body composition indices such as body mass index, fat-free mass, and trunk muscle mass. All trunk muscle densities were correlated with PAL. The product of the rectus abdominis muscle area and density showed the highest association with TEE (r = 0.732) and PAL (r = 0.578). Several trunk muscle measurements showed significant correlations with maximal inspiratory and expiratory pressures, indicating their roles in respiration.
CT-derived measurements for trunk muscles are helpful in evaluating physical status and function in patients with or at risk for COPD. Particularly, trunk muscle evaluation may be a useful marker reflecting TEE and PAL.
The aim of this study was to establish maturation-, age-, and sex-specific anthropometric and physical fitness percentile reference values of young elite athletes from various sports. Anthropometric ...(i.e., standing and sitting body height, body mass, body mass index) and physical fitness (i.e., countermovement jump, drop jump, change-of-direction speed i.e., T-test, trunk muscle endurance i.e., ventral Bourban test, dynamic lower limbs balance i.e., Y-balance test, hand grip strength) of 703 male and female elite young athletes aged 8-18 years were collected to aggregate reference values according to maturation, age, and sex. Findings indicate that body height and mass were significantly higher (p0.001; 0.95less than or equal todless than or equal to1.74) in more compared to less mature young athletes as well as with increasing chronological age (p0.05; 0.66less than or equal todless than or equal to3.13). Furthermore, male young athletes were significantly taller and heavier compared to their female counterparts (p0.001; 0.34less than or equal todless than or equal to0.50). In terms of physical fitness, post-pubertal athletes showed better countermovement jump, drop jump, change-of-direction, and handgrip strength performances (p0.001; 1.57less than or equal todless than or equal to8.72) compared to pubertal athletes. Further, countermovement jump, drop jump, change-of-direction, and handgrip strength performances increased with increasing chronological age (p0.05; 0.29less than or equal todless than or equal to4.13). In addition, male athletes outperformed their female counterpart in the countermovement jump, drop jump, change-of-direction, and handgrip strength (p0.05; 0.17less than or equal todless than or equal to0.76). Significant age by sex interactions indicate that sex-specific differences were even more pronounced with increasing age. Conclusively, body height, body mass, and physical fitness increased with increasing maturational status and chronological age. Sex-specific differences appear to be larger as youth grow older. Practitioners can use the percentile values as approximate benchmarks for talent identification and development.
Study design
A multicenter cross-sectional study.
Objectives
To clarify the relationship of trunk muscle mass with low back pain, spinal sagittal balance, and quality of life.
Summary of background ...data
Few reports have investigated the relationship of trunk muscle mass with lumbar spine function and spinal balance, and the clinical significance of trunk muscle mass remains unclear.
Methods
Patients attending spinal outpatient clinics at 10 different medical institutions were enrolled in this study. Patient demographics, trunk muscle mass and appendicular skeletal muscle mass (ASM) measured by bioelectrical impedance analysis (BIA), body mass index (BMI), Charlson Comorbidity Index (CCI), the Oswestry Disability Index (ODI), visual analog scale (VAS) for low back pain, sagittal vertical axis (SVA), and EuroQol 5 Dimension (EQ5D) score were investigated. Multivariate nonlinear regression analysis was used to investigate the association of trunk muscle mass with the ODI, VAS score, SVA, and EQ5D score.
Results
Of 2551 eligible patients, 1738 (mean age 70.2 ± 11.0 years; 781 men and 957 women) were enrolled. Trunk muscle mass was significantly correlated with the ODI, VAS score, SVA, and EQ5D score (
P
< 0.001) when adjusted for age, sex, BMI, ASM, CCI, and history of lumbar surgery. Patient deterioration was associated with a decrease in trunk muscle mass, and the deterioration accelerated from approximately 23 kg.
Conclusions
Trunk muscle mass was significantly associated with the ODI, VAS score, SVA, and EQ5D score. Trunk muscle mass may assume an important role to elucidate and treat lumbar spinal dysfunction and spinal imbalance.
Graphical abstract
These slides can be retrieved under Electronic Supplementary Material.
•Postural control declines with age.•Low back pain can affect balance performance during a one-legged stance.•Trunk muscle activation changes with age and the presence of low back pain.•Patients with ...chronic low back pain present decreased back muscle activation.
Postural control declines with age and can be affected by low back pain. Poor balance has been reported in people with chronic low back pain (CLBP), which in turn could be explained by the changes in trunk muscle activation.
Are there differences between younger and older adults with and without chronic low back pain (CLBP) on trunk muscle activity during one-legged stance task?
Twenty (20) with, and 20 subjects without nonspecific CLBP participated in the study. Each group was comprised of 10 younger (50% males; mean age: 31 years) and 10 older adults (50% males; mean age: 71 years). Subjects performed 3 × 30-second trials of one-legged stance, with eyes open, on a force platform, while surface electromyography (EMG) measurements were obtained bilaterally on the multifidus at L5, iliocostalis lumborum at L3, rectus abdominis and biceps femoris muscles.EMG amplitude analysis was processed by the Root Mean Square (250 ms window epochs) and normalized by the peak of activation during the balance tasks, to determine the muscular activity of each muscle.
Participants with CLBP presented 15% lower lumbar muscle activation (p < 0.05), and 23% higher co-activation (ratio between rectus adominis by multifidus) than participants without CLBP, regardless of age. Significant differences (p < 0.05) between older and young groups were observed only for lower lumbar muscles (mean 24% lower in older than younger adults) and rectus adominis muscles (mean 17% lower in older than younger adults).
CLBP individuals have different trunk muscle activity than those without CLBP, and older adults exhibit lower trunk activation during one-legged stance balance task. The use of the EMG in evaluation of trunk neuromuscular function during one-legged stance may thus be a valuable tool when assessing balance in CLBP and older people.
Purpose
The interrelations between age-related muscle deterioration (sarcopenia) and vertebral fractures have been suggested based on clinical observations, but the biomechanical relationships have ...not been explored. The study aim was to investigate the effects of muscle ageing and sarcopenia on muscle recruitment patterns and spinal loads, using musculoskeletal multi-body modelling.
Methods
A generic AnyBody model of the thoracolumbar spine, including > 600 fascicles representing trunk musculature, was used. Several stages of normal ageing and sarcopenia were modelled by reduced strength of erector spinae and multifidus muscles (ageing from 3rd to 6th life decade: ≥ 60% of normal strength; sarcopenia: mild 60%, moderate 48%, severe 36%, very severe 24%), reflecting the reported decrease in cross-sectional area and increased fat infiltration. All other model parameters were kept unchanged. Full-range flexion was simulated using inverse dynamics with muscle optimization to predict spinal loads and muscle recruitment patterns.
Results
The muscle changes due to normal ageing (≥ 60% strength) had a minor effect on predicted loads and provoked only slightly elevated muscle activities. Severe (36%) and very severe (24%) stages of sarcopenia, however, were associated with substantial increases in compression (by up to 36% or 318N) at the levels of the upper thoracic spine (T1T2–T5T6) and shear loading (by up to 75% or 176N) along the whole spine (T1T2–L4L5). The muscle activities increased for almost all muscles, up to 100% of their available strength.
Conclusions
The study highlights the distinct and detrimental consequences of sarcopenia, in contrast to normal ageing, on spinal loading and required muscular effort.
Graphical abstract
These slides can be retrieved under Electronic Supplementary Material.
Abstract Ligaments assist trunk muscles in balancing external moments and providing spinal stability. In absence of the personalized material properties for ligaments, finite element (FE) models use ...dispersed data from the literature. This study aims to investigate the relative effects of eight different ligament property datasets on FE model responses. Eight L4-L5 models distinct only in ligament properties were constructed and loaded under moment (15 N m) alone or combined with a compressive follower load (FL). Range of motions (RoM) of the disc-alone model matched well in vitro data. Ligament properties significantly affected only sagittal RoMs (∼3.0–7.1° in flexion and ∼3.8–5.8° in extension at 10 N m). Sequential removal of ligaments shifted sagittal RoMs in and out of the corresponding in vitro ranges. When moment was combined with FL, center of rotation matched in vivo data for all models (3.8 ± 0.9 mm and 4.3 ± 1.8 mm posterior to the disc center in flexion and extension, respectively). Under 15 N m sagittal moments, ligament strains were often smaller or within the in vitro range in flexion whereas some posterior ligament forces approached their failure forces in some models. Ligament forces varied substantially within the models and affected the moment-sharing and internal forces on the disc and facet joints. Intradiscal pressure (IDP) had the greatest variation between models in extension. None of the datasets yielded results in agreement with all reported measurements. Results emphasized the important role of ligaments especially under larger moments and the need for their accurate representation in search for valid spinal models.
This study investigated the age-related changes in muscle quantity and quality in the trunk and limbs of women. A total of 128 females were divided into four age groups: young, middle-aged, young-old ...and old-old. Muscle thickness (MT) and echo intensity (EI) of the biceps brachii, quadriceps femoris, rectus abdominis, external oblique, internal oblique and transversus abdominis were measured using B-mode ultrasonography. The EIs of the biceps brachii, quadriceps femoris and transversus abdominis were significantly higher in the middle-aged group than in the young group; however, there were no significant differences in MT. Compared with the young group, all other groups had significant changes in both MT and EI of the rectus abdominis, external oblique and internal oblique muscles. Thus, qualitative changes in muscle may occur earlier than quantitative changes, and loss of muscle mass may occur earlier in the superficial abdominal muscles than in the other muscles.
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