Deep Muscle Group Research Articles

Novel Muscle Sensing by Radiomyography (RMG) and Its Application to Hand Gesture Recognition.

Conventional electromyography (EMG) measures the continuous neural activity during muscle contraction, but lacks explicit quantification of the actual contraction. Mechanomyography (MMG) and accelerometers only measure body surface motion, while ultrasound, CT-scan and MRI are restricted to in-clinic snapshots. Here we propose a novel radiomyography (RMG) for continuous muscle actuation sensing that can be wearable or touchless, capturing both superficial and deep muscle groups. We verified RMG experimentally by a wearable forearm sensor for hand gesture recognition (HGR). We first converted the sensor outputs to the time-frequency spectrogram, and then employed the vision transformer (ViT) deep learning network as the classification model, which can recognize 23 gestures with an average accuracy up to 99% on 8 subjects. By transfer learning, high adaptivity to user difference and sensor variation were achieved at an average accuracy up to 97%. We further extended RMG to monitor eye and leg muscles and achieved high accuracy for eye movement and body posture tracking. RMG can be used with synchronous EMG to derive stimulation-actuation waveforms for many potential applications in kinesiology, physiotherapy, rehabilitation, and human-machine interface.

Unexplained bacterial meat spoilage during the moose hunting in northern Norway – a review of cases 2008–2021

BackgroundSudden and unexpected spoilage of moose (Alces alces) carcasses has incidentally been reported in northern Norway. Hunters describe a strong foul odour and greenish discolouration of moose carcasses, hence the nickname “green moose”. Finnmark Estate has registered all reported cases of “green moose” in Finnmark county in the period 2008–2021. In 2013, a questionnaire was introduced to gather more detailed information. Bacteriological and histological examinations were performed on submitted samples of spoiled moose meat. The aim of the present report is to summarize the data gathered about the “green moose” cases, and to discuss possible causes.ResultsNinety-three valid cases of “green moose” meat spoilage were registered in Finnmark county, giving this form of meat spoilage a prevalence of 0.85% of hunted moose. The carcass weights of spoiled carcasses were within normal weights for moose carcasses in Finnmark. Adult bulls were significantly more, and calves were less frequently affected by meat spoilage. No distinct geographical pattern or “hotspots” could be identified, but multiple cases in the same hunting area same year were reported. The meat spoilage was detected within 5 h after shooting in five cases, and 53% of cases were detected within 2 days after shooting. The meat spoilage was primarily found in deep muscle groups. Bacteriological analyses of 13 samples of spoiled meat were not conclusive. A mixture of aerobic bacteria was detected in 12 samples, and swarming clostridia in 10 samples. Histological examination of seven samples showed abundance of bacteria in fasciae and connective tissue surrounding blood vessels. Injury shootings were not more frequent in “green moose” cases than in moose hunting in general. Other possibly predisposing events to meat spoilage were evisceration later than 60 min after shooting, delayed skinning and contamination by ruminal content. Whether these events occurred more often in “green moose” than normal moose was difficult to determine, due to lack of reference data.ConclusionsBased on the bacteriological results and the characteristics of the meat spoilage we suggest that clostridia are a main factor involved. How and why clostridia are spread to the muscles and causing the often rapid meat spoilage, is unexplained.

Comparison of the soleus and plantaris muscles in humans and other primates: Macroscopic neuromuscular anatomy and evolutionary significance.

In humans, the soleus is more developed compared to other primates and has a unique architecture composed of anterior bipennate and posterior unipennate parts, which are innervated by different nerve branches. The anterior part of the human soleus was proposed to be important for bipedalism, however, the phylogenetic process resulting in its acquisition remains unclear. Providing insights into this process, the anterior part of the soleus was suggested to be closely related to the plantaris based on the branching pattern of their nerve fascicles. To reveal the phylogeny of the soleus and plantaris in primates, the innervation patterns of the posterior crural muscles were compared among a wide range of species. From their branching pattern, posterior crural muscles could be classified into superficial and deep muscle groups. The anterior part of the soleus and plantaris both belonged to the deep muscle group. In all the examined specimens of ring-tailed lemurs and chimpanzees, as well as in one out of two specimens of siamang, the nerve branches corresponding to those innervating the anterior part of the human soleus were found. The muscular branches innervating the anterior part of the soleus and plantaris formed a common trunk or were connected in all the specimens. These results indicate that the anterior part of the soleus is closely related to the plantaris across different species of primates. In turn, this suggests that the anterior part of the soleus is maintained among primates, and especially in humans, where it develops as the characteristic bipennate structure.

MRI Segmentation of Cervical Muscle Volumes in Survived Strangulation: Is There an Association between Side Differences in Muscle Volume and the Handedness of the Perpetrator? A Retrospective Study.

We evaluate the potential value of magnetic resonance imaging (MRI) in the examination of survivors of manual strangulation. Our hypothesis was that trauma-induced edema of the cervical muscles might lead to a side difference in the muscle volumes, associated with the handedness of the perpetrator. In 50 individuals who survived strangulation, we performed MRI-based segmentation of the cervical muscle volumes. As a control group, the neck MRIs of 10 clinical patients without prior trauma were used. The ratio of the right to left muscle volume was calculated for each muscle group of the control and strangulation groups. Cutoff values for the assumed physiological muscle volume ratios between the right and left sides were identified from our control group. There was no significant difference among the individuals in the pathological muscle volume ratio between right-handed versus both-handed strangulation for the sternocleidomastoid, pretracheal, anterior deep, or trapezoid muscle groups. Only the posterior deep muscle group showed a statistically significant difference in the pathological muscle volume ratio for both-handed strangulations (p = 0.011). Measurement of side differences in cervical muscle volume does not allow for a conclusion concerning the probable handedness of the perpetrator.

Meta-Analysis of Elderly Lower Body Strength: Different Effects of Tai Chi Exercise on the Knee Joint-Related Muscle Groups.

Objective To determine whether lower body strength such as keen extension and flexion strength may be improved by Tai Chi exercise in older adults from the perspective of evidence-based medicine. Methods Databases of PubMed, Embase, and Cochrane Library were searched up to July 1, 2021. Randomized clinical trials are adopted to compare Tai Chi exercise with sedentary behavior or other low intensity exercise in terms of influence on lower body strength rehabilitation, especially keen extension and flexion strength in people aged over 60. A meta-analysis was performed to discuss outcomes of lower body strength, knee muscle strength, and knee extension/flexion strength. Results A total of 25 randomized trials involving 1995 participants fulfilled the inclusion criteria. (1) Tai Chi exercise significantly improved elderly lower body strength (−0.54, [−0.81, −0.28], p < 0.00001, I2 = 74%), but there was no differential improvement in the strength of the knee joints (0.10, [−0.02, 0.23], p=0.11, I2 = 34%). (2) Elderly individual lower body strength declined with age, while this trend was suppressed by Tai Chi exercise (−0.35, [0.14, 0.56], p=0.001, I2 = 70%). (3) Although Tai Chi exercise did no significantly improve the large muscle group of knee joint extensor like quadriceps femoris (3.15, [−0.69, 6.99], p=0.24, I2 = 26%), it showed marked enhancement to the strength of deep small muscle group of knee joint flexor (10.25, [6.90, 13.61], p < 0.00001, I2 = 0%). The heterogeneity might be caused by distinguished measurements of muscle strength. Therefore, Tai Chi exercise specifically enhanced some certain muscle strength of knee joints and improved muscle fitness rehabilitation as well as function activity for elderly. Conclusions In this RCT meta-analysis, Tai Chi exercise has positive effects on lower body strength of elderly. Although no obvious improvement on the knee extensor is observed, it may be used as a rehabilitation treatment for training stable deep muscle groups to improve the knee flexion strength significantly.

Damages of Neuromuscular System After Mechanical-Induced Limb Ischemia (Experimental Study)

Relevance. Traumatic and ischemic injury of the limbs is accompanied by damage of the skeletal muscles and peripheral nerves of the limbs. The dynamics and consequences of ischemic lesions remain poorly understood and need to be corrected.&#x0D; Objective: using quantitative morphological and sonographic methods, to study the dynamics of skeletal muscle damage of the limb after traumatically induced ischemia with and without the injection of platelet-rich plasma, bone marrow aspirate, and adipose tissue fraction.&#x0D; Materials and Methods. In 3 experiments, rabbits were modeled with 6-hour limb ischemia by applying an elastic tourniquet. After compartment syndrome detection, based on the assessment of subfascial pressure, cell suspensions were injected into the leg muscles. Sonographic and histological examination of the muscles was performed on days 5, 15, and 30. The results of sonography and morphometry were evaluated by statistical methods.&#x0D; Results. The developed model of ischemia consists of 6-hour immobilization of the limb, on тwhich medical elastic tourniquets were imposing. The action of the tourniquets causes high subfascial pressure and necrosis of the superficial muscle groups of the lower third of the thigh and lower leg. According to sonography, the δ-entropy of damaged tissues on day 5 is reduced relative to the intact limb, as in the case of administration of bone marrow aspirate cells. On days 15 and 30, sonography showed no difference between the comparison groups. The dynamics of morphological features of limb tissue damage consist of necrosis of superficial muscle groups, atrophy in the middle layers, and almost intact deep muscle groups. Necrosis was replaced by scar tissue, the density of which increases 11-14 times, and does not differ in the period 5-30 days. The administration of platelet plasma, bone marrow aspirate, and adipose tissue fraction did not change the dynamics of fibrotic changes in ischemic damaged muscles. Muscle atrophy is accompanied by activation of endogenous repair of single muscle fibers, which tended to intensify after injection of bone marrow aspirate. The sciatic nerve of the injured limb was not structurally damaged according to the deep topography, while the nerves of the tibia develop degenerative changes from the 15th day.

Iliopsoas the Hidden Muscle: Anatomy, Diagnosis, and Treatment.

The iliopsoas is a deep muscle group which anatomically connects the spine to the lower limbs. It is composed of the iliacus, psoas major, and psoas minor muscles. The iliopsoas functions as the primary hip flexor. Because the iliopsoas is important for daily activities, including sports, impairments and pathology associated with this muscle group can cause significant limitations. Evaluating pathology associated with the iliopsoas muscle group can be challenging because the patient's complaints are often vague and difficult to discern from other hip problems. This article will review relevant anatomy, discuss common pathologies, present clinical based examination methods, and outline conservative treatment interventions focusing on manual therapy and active exercises.

MRI Findings of Early Myositis Ossificans without Calcification or Ossification.

Purpose To characterize and evaluate the MR imaging features of early myositis ossificans (MO) without calcification or ossification. Methods The MRI manifestations of seven patients with pathologically proven early MO were retrospectively analyzed with regard to tumor location, size, margins, signal intensity, and enhancement appearance in MR images. Additionally, the surrounding soft-tissue edema and adjacent bone change were assessed. Results All cases (n=7) had intramuscular tumor-like masses without calcifications. The lesions appeared as isointense in T1-weighted images (T1-WI) and inhomogeneous hyperintense in T2-weighted MR images (T2-WI). On T2-WI and postcontrast T1-WI, the heterogeneously high signal intensity in the expanded muscle interspersed with a few hypointense linear structures consistent with intact muscle fibers showed “striate pattern” in the plane parallel with muscle fibers. The relatively hypointense areas with geometrical pattern consistent with the bundles of intact muscle fibers are found within the lesion with diffuse high signal intensity, displaying the “checkerboard-like pattern” in the plane vertical to muscle fibers. A “striate pattern” (n = 7) and “checkerboard-like pattern” (n = 3) in the lesion appeared in T2-WI. In contrast-enhanced MRI images, all cases showed diffuse “striate pattern” enhancement. Among them, one case demonstrated “checkerboard-like pattern” enhancement. All cases had diffuse and prominent muscle edema that preserved the muscle fascicles. For two lesions located in the deep muscle group, the adjacent bone showed bone marrow edema. Conclusion MR imaging has unique advantages for diagnosis of early MO without calcification or ossification: the “striate pattern” and “checkerboard-like pattern” appearance shown in T2-WI and contrast-enhanced MRI images can be helpful for differential diagnosis. MRI can delineate the extent of the tumor and provides accurate anatomical information, which is important in diagnosis, treatment, and follow-up.

척추 운동 분절의 유합에 따른 주변 근육력의 변화 및 인접 분절 추간판의 추가적 변성에 대한 해석

The incidence of adjacent segment degeneration (ASD) after lumbar spinal fusion have not been precisely verified. In the presence of mild degeneration in the proximal segment adjacent to the fused segment, selection of additional fusion is not agreed upon. Muscle activity change and ASD after fusion was analyzed with a developed three-dimensional finite element model of musculoskeletal system. The paraspinal muscle activities were calculated based on a hypothesis, the intervertebral disc was assumed to have a transducer function and the muscle is activated according to a sensor driven control mechanism to maintain the stability of the lumbar spine. Simulation was conducted for erect standing and 60° isometric forward flexed posture. Total muscle force produced in each deep muscle group was similar however activity of some muscle fascicles which inter-connected to the vertebrae above the fused segment showed increased value. In the presence of mild degeneration in the proximal adjacent segment, muscle activity across the degenerated segment was reduced. Despite changes in muscle activity, nucleus pressure at adjacent segment was increased in both cases. This change would eventually lead to the ASD.

Muscle localization of heterotopic ossification following spinal cord injury

Background ContextHeterotopic ossification (HO) is a known complication especially in people with traumatic spinal cord injury (SCI). Although some risk factors have already been described, the pathophysiology of HO is still unknown. The pelvis is the most common region for HO occurrence. However, the prevalence of HO by muscle groups about the hip is not well described. PurposeTo analyze the prevalence of early HO in muscle groups about the hip in 267 patients with SCI. Patient Sample267 patients with traumatic SCI and pelvic HO. MethodsBetween January 2001 and December 2014, 267 patients with SCI were treated in our university hospital and were included in the study. Patients were routinely screened for HO using ultrasound. The diagnosis of HO was validated using magnetic resonance imaging (MRI) or computed tomography (CT). The primary outcome measure was the prevalence of HO by muscle groups around the hip. The following muscle groups around the hip were defined: (1) gluteal group, (2) adductor group, (3) iliopsoas group, and (4) deep muscle group. Additionally, the prevalence of concomitant trochanteric bursitis was recorded in all cases. ResultsThe gluteal group showed the highest HO prevalence with 55.8%, followed by the deep muscle group with 31.1%. Concomitant trochanteric bursitis was found in 62 patients (23.2%). No association between pelvic trauma and HO development was observed (n=16, 11%). ConclusionsThe most common muscular location for the occurrence of HO about the hip was the gluteal muscle group. Considering that no laboratory parameters are currently available for screening for HO, highly sensitive ultrasound screening examinations should be routinely performed, with particular attention paid to the gluteal muscles. Additionally, routine range of motion examination for extension and external rotation of the hip joint is warranted.

Novel technique for three-dimensional visualisation and quantification of deformable, moving soft-tissue body parts

Three-dimensional (3D) imaging of delicate, moving soft-tissue body parts is very difficult. Our understanding of the muscles that control lip movements is based largely on histological and cadaveric studies, which provide scant information about dynamic morphology. Our aim was to develop an innovative scanning technique for the imaging and reconstruction of dynamic orofacial morphology by use of 3D and four-dimensional (4D, ie, 3D plus time) ultrasonography. Four volunteers (including one patient) underwent ultrasonography with 3D/4D imaging systems. To avoid deformation of the delicate orofacial structures, a water bath with an acoustic window was devised. The orofacial part was immersed in the bath throughout scanning, and a timer was used to synchronize lip movements with the 4D scan. 4D views showed the functional differences in superficial and deep muscle groups of the lips, and clearly showed the changes occurring with movement of the lips and mouth. In the patient, a pathological layer and its extension corresponding to surface malformation were clearly identified. We have developed a prototype device that has made possible 3D and 4D examination of orofacial anatomy and function. With further refinement of the device and improvement in 4D acquisition timing, this technique may offer a new way of dynamically imaging and quantifying many soft-tissue parts in 3D without deforming structure or disturbing function.

EXPERIMENTAL STUDIES ON MUSCULAR RESPONSES OF INNER EAR ORIGIN IN RABBITS PRESSURE STIMULATION ON THE LABYRINTH

Giving compression and aspiration stimuli to the unilateral external meatus, the middle ear and the lateral semicircular canal of rabbits, labyrinthine tonic muscle responses were studied by inducing muscular potential from the surface muscle group (M. trapezius and M. splenius) and the deep muscle group (M. rectos capitis posterior minor et major and M. obliquus capitis superior) of the nape. The results obtained are as follows : I, By a minimal pressure to which a muscular response is available, clinically it develops the eye- and the head- deviation which is produced by only stimuli of the lateral semicircular canal. On electromyogram, the deep muscle group on the side of the non-stimulated ear shows increasing tonic muscle discharge by compressive stimuli, but shows the decrease by aspirative stimuli. The lateral semicircular canal shows more marked tonic muscle response than any other portions., That is, the compressive stimuli increase labyrinthine muscle tonus and facilitat laby- rinthine functions, while the aspirative stimuli decrease the former and inhibit the latter. 2. The tonic muscle responses shown by the EMG of the deep muscle group, appear earlier than ocular nystagmus does. When the nystagmus occcurs, electromyographical muscle responses are marked, but they become irregular being influenced by extra-labyrinthine factors. 3. The tonic muscle responses in the surface muscle group do not seem to be directry related with labyrinthine pressure stimuli, though a further study is required before the assumption is established, 4. The result of pressure stimuli supports the contralateral innervation theory of the musc- ular tonus of inner ear origin in the deep muscle group.