A Cadaveric Study of Palmaris Longus Muscle

Background: Aim: To assess the palmaris longus muscle.Methods:40 formalin fixed cadavers of both genders were included. Routine dissection of the upper limb was carried following the Cunnigham’s Manual of Practical Anatomy. During the dissection of the anterior compartment of forearm, the Palmaris longus muscle was identified & carefully dissected.Results:Out of 40 cadavers, 22 were of males and 18 were of females. Morphology of Palmaris longus found to be normal in 18, agenesis in 6, fusiform in 4, hybrid in 6, bifurcated tendon in 5 and fleshy in 1 case. A significant difference was observed (P< 0.05).Conclusions:Surgeon must be aware of the variations of palmaris longus muscle. Morphology of Palmaris longus found to be normal, agenesis, fusiform, hybrid, bifurcated tendon and fleshy.

Gross anatomy of the gluteal and posterior thigh muscles in koalas based on their innervations

There are not many descriptions of the muscle morphology of marsupials, despite the fact that they should show diversity according to the adaptation and dispersal to a variety of environments. Most of the previous studies regarding the gross anatomy of marsupials were conducted in the 1800 - 1900’s, and many issues still remain that need to be reexamined. For instance, the muscle identification had been performed based only on their attachments and thus, muscle descriptions are often inconsistent among the studies. These classic studies often do not include figures or photographs, so the discrepancies in the descriptions of the muscles could only be verified by performing the muscle identification again with a more reliable method. This problem can be solved by performing muscle identification by innervation. This method, which focuses on the ontogenic origin of the muscle as opposed to the attachment site, is prone to individual and interspecies variation and is a common technique in recent anatomical research. This technique is more reliable than previous methods and is suitable for comparison with other taxa (i.e., eutherians). In this study, we first conducted muscle identification based on innervation in the gluteal and posterior thighs of koalas in order to reorganize the anatomical knowledge of marsupials. This is because the gluteus and posterior thighs of koalas are the areas where previous studies have been particularly inconsistent. We dissected five individual koalas and clarified discrepancies in previous studies, as well as investigated the unique muscle morphology and their function in koalas. Specifically, the koala's gluteal muscle group is suitable for abduction, while the posterior thigh muscles are particularly suitable for flexion. In the future, we will update the anatomical findings of marsupials in the same way to clarify the adaptive dissipation process of marsupials, as well as to contribute to the understanding of the evolutionary morphology of mammals.

Training-Induced Muscle Adaptations During Competitive Preparation in Elite Female Rowers

Training-induced adaptations in muscle morphology, including their magnitude and individual variation, remain relatively unknown in elite athletes. We reported changes in rowing performance and muscle morphology during the general and competitive preparation phases in elite rowers. Nineteen female rowers completed 8 weeks of general preparation, including concurrent endurance and high-load resistance training (HLRT). Seven rowers were monitored during a subsequent 16 weeks of competitive preparation, including concurrent endurance and resistance training with additional plyometric loading (APL). Vastus lateralis muscle volume, physiological cross-sectional area (PCSA), fascicle length, and pennation angle were measured using 3D ultrasonography. Rowing ergometer power output was measured as mean power in the final 4 minutes of an incremental test. Rowing ergometer power output improved during general preparation [+2 ± 2%, effect size (ES) = 0.22, P = 0.004], while fascicle length decreased (−5 ± 8%, ES = −0.47, P = 0.020). Rowing power output further improved during competitive preparation (+5 ± 3%, ES = 0.52, P = 0.010). Here, morphological adaptations were not significant, but demonstrated large ESs for fascicle length (+13 ± 19%, ES = 0.93), medium for pennation angle (−9 ± 15%, ES = −0.71), and small for muscle volume (+8 ± 13%, ES = 0.32). Importantly, rowers showed large individual differences in their training-induced muscle adaptations. In conclusion, vastus lateralis muscles of elite female athletes are highly adaptive to specific training stimuli, and adaptations largely differ between individual athletes. Therefore, coaches are encouraged to closely monitor their athletes' individual (muscle) adaptations to better evaluate the effectiveness of their training programs and finetune them to the athlete's individual needs.

The Effect of Phasic Versus Combined Neuromuscular Electrical Stimulation Using the StimaWELL 120MTRS System on Multifidus Muscle Morphology and Function in Patients with Chronic Low Back Pain: A Randomized Pilot Control Trial Protocol

BackgroundNeuromuscular electrical stimulation (NMES) is used to improve muscle strength clinically when rehabilitating various musculoskeletal disorders. However, the effects of NMES on muscle morphology and function in individuals with non-specific chronic low back pain (CLBP) have scarcely been investigated. Although research links deficits in the paraspinal musculature with subjective reports of pain and disability, it is unknown if treatment with NMES can help reverse these deficits. Therefore, the primary aim of this study is to compare the effects of two muscle therapy protocols with a medium-frequency electrotherapy device (the StimaWELL 120MTRS system) on multifidus muscle morphology in CLBP patients. The secondary aims are to determine the effects of these protocols on multifidus muscle function, as well as subjective reports of pain intensity, pain interference, disability, and catastrophizing. MethodsA total of 30 participants with non-specific CLBP, aged 18-60, will be recruited from local orthopedic clinics and databases. Participants will be randomized (1:1) to either the phasic or combined (phasic + tonic) muscle therapy protocols on the StimaWELL 120MTRS system. Participants will undergo 20 supervised electrotherapy treatments over a 10-week period. The primary outcomes will be multifidus cross-sectional area (CSA) and fat infiltration. Secondary outcomes will include multifidus contraction (measured via %thickness change from a rested to contracted state), multifidus stiffness (at rest, and during contraction), as well as pain intensity, interference, disability, and catastrophizing. Both primary and secondary outcomes will be obtained at baseline and at 11-weeks; secondary outcomes measured via questionnaires will also be obtained at 6-weeks, while low back pain intensity will be measured before and after each treatment. Paired t-tests will be used to assess within-group changes for all primary outcome measures. A two-way repeated-measures analysis of variance will be use to assess changes in secondary outcomes over time. DiscussionThe results of this trial will help clarify the role of medium-frequency NMES on lumbar multifidus morphology and function. Trial RegistrationNCT04891692 Trial SponsorConcordia University, Montreal, Quebec, Canada

Validity of freehand three-dimensional ultrasound system in measurement of three-dimensional surface shape of shoulder muscles

Accurate measurement of muscle morphology is crucial for assessing skeletal muscle capacity. Although the freehand three-dimensional ultrasound (3DUS) system is a promising technique for assessing muscle morphology, its accuracy has been validated mainly in terms of volume by examining lower limb muscles. The purpose of this study was to validate 3DUS in the measurements of 3D surface shape and volume by comparing them with MRI measurements while ensuring the reproducibility of participant posture by focusing on the shoulder muscles. The supraspinatus, infraspinatus, and posterior deltoid muscles of 10 healthy males were scanned using 3DUS and MRI while secured by an immobilization support customized for each participant. A 3D surface model of each muscle was created from the 3DUS and MRI methods, and the agreement between them was assessed. For the muscle volume, the mean difference between the two models was within 0.51 cm3 for all muscles. For the surface shape, the distances between the closest points of the two models was calculated for every point on the 3DUS surface model. The results showed that the median (third quartile) of the distances was less than 1.21 mm (1.89 mm) for all muscles. These results suggest that, given the above error is permitted, 3DUS can be used as an alternative to MRI in measuring volume and surface shape, even for the shoulder muscles.

Length-dependent changes of lower limb muscle morphology in Chronic Inflammatory Demyelinating Polyneuropathy assessed with magnetic resonance imaging

The objective of the present study was to assess muscle quantity of the thigh and leg in patients with chronic inflammatory demyelinating polyneuropathy (CIDP) compared to age and sex matched controls in exploring length-dependent changes of innervated muscles. In five people with CIDP and seven controls, magnetic resonance imaging was used to assess muscle morphology of the four parts of the quadriceps and medial hamstring muscles. Findings were compared to the triceps surae from a subset of participants. The CIDP group had less contractile tissue in the quadriceps (11.5%, P<0.05), hamstrings (15.6%, P<0.05) and triceps surae (35.9%, P<0.05) compared to controls. Additionally, CIDP had less contractile tissue (18.7%) in the triceps surae compared to the hamstrings (P<0.05). Muscle quantity in the quadriceps and hamstrings in CIDP was less than controls, but differences were greater for the distal triceps surae. These findings support a length-dependent affect of CIDP on limb musculature composition.

A study of psoas minor muscle morphology

Psoas minor is long, slender skeletal muscle it lies anterior to psoas major. It is an inconstant muscle. It was absent in 40-70% of subjects. To determine the frequency and morphometry of psoas minor muscle.: 20 cadavers were dissected during routine dissection for undergraduate students at Ayaan institute of medical sciences, Moinabad, Hyderabad and Government medical college, Mahabubnagar. Bilateral variations were observed in one specimen, unilateral variations were observed in two specimens.: Out of forty specimens Psoas minor was present in three specimens. In one specimen bilateral variations observed, other two specimens unilateral. If it is present, clinical importance to radiologists, surgeons and physiotherapists as it can mimic certain abdominal emergencies.