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BackgroundThe radial groove is known as a sulcus on the posterior humerus and protects the radial nerve from adjacent muscle and soft tissue. In the literature, there exists heterogeneity regarding the presence of an actual radial groove and the radial nerve’s interaction with the periosteum of the humerus. This study aimed to determine if there is a real radial groove, “sulcus,” and define the relationship between the radial nerve and the periosteum of the posterior humerus.MethodsEighteen fresh-frozen cadaveric specimens were dissected using a posterior triceps splitting approach. The radial nerve’s interaction with the periosteum of the humerus was determined. The presence of a visible and palpable radial groove was also examined.ResultsIn 56% of specimens, the radial nerve was directly seated over the periosteum of the posterior humerus (direct contact between the nerve and bone). In comparison, 44% of specimens had a layer of the medial head of the triceps brachii muscle fibers interposition between the nerve and bone. 89% of specimens had no visible or palpable radial groove. In 11% of specimens, there was mild palpable depression.ConclusionThis study shows that the radial groove may not exist and is probably not a true anatomical structure. In addition, the nerve is in direct contact with the posterior periosteum of the humerus in most specimens. These anatomic relationships and findings add to the anatomical understanding of the radial nerve, which helps during operative approaches and fixation of the humerus.

ObjectivesAssess the insertional anatomy of the distal aspect of the triceps brachii muscle using magnetic resonance imaging (MRI) in cadavers with histologic correlation and Play-doh® models of the anatomic findings.MaterialsElbows were obtained from twelve cadaveric arm specimens by transverse sectioning through the proximal portion of the humerus and the midportion of the radius and ulna. MRI was performed in all elbows. Two of the elbow specimens were then dissected while ten were studied histologically. Subsequently, Play-doh® models of the anatomic findings of the distal attachment sites of the triceps brachii muscle were prepared.ResultsMRI showed a dual partitioned appearance of the distal attachment sites into the olecranon in all specimens. In the deeper tissue planes, the medial head muscle insertion was clearly identified while superficially, the terminal portion of the long and lateral heads appeared as a conjoined tendon. Histologic analysis, however, showed continuous tissue rather than separate structures attaching to the olecranon.ConclusionAlthough MRI appeared to reveal separate and distinct attachments of the triceps brachii muscle into the olecranon, histologic analysis delineated complex but continuous tissue related to the attachments of the three heads of this muscle. The Play-doh® models were helpful for the comprehension of this complex anatomy and might serve as a valuable educational tool when applied to the analysis of other musculoskeletal regions.

Shoulder pathologies are a common reason for presentation to veterinary sports medicine and rehabilitation practices. Currently there are no standardized rehabilitation protocols for shoulder injuries but controlled walking, either on flat ground or on inclines/declines, is recommended in nearly every recovery rehabilitation program. The objective of this study was to evaluate the peak and average muscle activity of commonly targeted forelimb muscle groups using fine-wire and surface electromyography (EMG) during treadmill walking at five treadmill positions. Our hypothesis was that the forelimb muscle activity would be significantly higher during decline walking than level walking and significantly lower during incline walking. Fine-wire and surface EMG of the supraspinatus, deltoideus, biceps brachii and lateral head of the triceps brachii muscles were performed during treadmill walking at 0, 5% incline, 10% incline, 5% decline, and 10% decline. The average and peak muscle enveloped EMG signals for 10 gait cycles were compared between the treadmill positions. Significant main effects were seen during decline walking for average supraspinatus muscle activity (  < 0.001), and both average and peak deltoideus muscle activity (  = 0.021,  < 0.001) respectively. There were no significant differences for peak or average lateral triceps brachii or biceps brachii activity between treadmill positions. Decline walking significantly increases muscle activity in the supraspinatus and deltoideus muscles of dogs. This study provides new insights regarding the muscle activity of the thoracic limbs in dogs during various treadmill positions at the walk. The impact of incremental treadmill positions on the average supraspinatus EMG activity, along with increases in the average and peak EMG activity of the deltoideus muscle during decline walking should be considered when developing a therapeutic exercise plan in canine patients with shoulder injuries.

IntroductionThe medial head of the triceps brachii flap is already described as a local muscular or as a free flap. It allows coverage of defects of the posterior cubital region. The aim of this study was to describe the vascular anatomy of the musculocutaneous medial triceps brachii pedicled flap.MethodsEleven fresh–frozen upper limbs (6 come from women and 5 from men) were proximally injected with Indian ink agar solution. The medial head of the triceps brachii muscle was dissected and the superior ulnar collateral artery (SUCA) was isolated with its collaterals. The collateral arteries were dissected to determine whether there were septocutaneous or musculocutaneous arteries for vascularization of the skin in front of the medial head. Lengths of those collaterals arteries were measured.ResultsThe average number of collaterals arteries from the SUCA supplying the medial head of the triceps brachii is 4.5 (from 3 to 6 arteries). Among these collaterals’ arteries, there are one average 1.5 (0.6–4.5) septocutaneous arteries and 3 (1–4.8) musculocutaneous arteries.Discussion and conclusionA musculocutaneous flap with the medial head of the triceps brachii muscle can be described with the muscle. The SUCA gives perforator arteries musculocutaneous and septocutaneous for the vascularization of the triceps brachii medial head. The use of local pedicled flap with similar tissue maximizes healing with a minimal morbidity of the donor site. This study demonstrated the feasibility of the medial head triceps brachii musculocutaneous flap to cover defect of the posterior aspect of the elbow.

To systematically review the effects of exercise on fascicle geometry and muscle size parameters of the upper extremity muscles, the CENTRAL, CINAHL, PubMed and OpenGrey databases were searched on 31 July 2021. Finally, 17 randomised controlled trials (RCTs) were included in this systematic review. High-intensity bench press training (g = 1.03) and 12 RM bench press exercises (g = 1.21) showed a large effect size on increasing pectoralis major muscle size. In the elbow extensors, large effects were reported for an increase in muscle size with isometric maximal voluntary co-contraction training (g = 1.97), lying triceps extension exercise (g = 1.25), and nonlinear periodised resistance training (g = 2.07). In addition, further large effects were achieved in the elbow flexors via traditional elbow flexion exercises (g = 0.93), concentric low-load forearm flexion-extension training (g = 0.94, g = 1), isometric maximal voluntary co-contraction training (g = 1.01), concentric low-load forearm flexion-extension training with blood flow restriction (g = 1.02, g = 1.07), and nonlinear periodised resistance training (g = 1.13, g = 1.34). Regarding the forearm muscles, isometric ulnar deviation training showed a large effect (g = 2.22) on increasing the flexor carpi ulnaris and radialis muscle size. Results show that these training modalities are suitable for gaining hypertrophy in the relevant muscles with at least four weeks of training duration. Future RCTs should investigate the effects of exercise modalities on the triceps brachii fascicle geometry, the infraspinatus muscle thickness (MT) and the subscapular MT due to their associations with sports performance.

There have always been practical demands for objective and accurate assessment of muscle spasticity beyond its clinical routine. A novel regression-based framework for quantitative assessment of muscle spasticity is proposed in this paper using wearable surface electromyogram (EMG) and inertial sensors combined with a simple examination procedure. Sixteen subjects with elbow flexor or extensor (i.e., biceps brachii muscle or triceps brachii muscle) spasticity and eight healthy subjects were recruited for the study. The EMG and inertial data were recorded from each subject when a series of passive elbow stretches with different stretch velocities were conducted. In the proposed framework, both lambda model and kinematic model were constructed from the recorded data, and biomarkers were extracted respectively from the two models to describe the neurogenic component and biomechanical component of the muscle spasticity, respectively. Subsequently, three evaluation methods using supervised machine learning algorithms including single-/multi-variable linear regression and support vector regression (SVR) were applied to calibrate biomarkers from each single model or combination of two models into evaluation scores. Each of these evaluation scores can be regarded as a prediction of the modified Ashworth scale (MAS) grade for spasticity assessment with the same meaning and clinical interpretation. In order to validate performance of three proposed methods within the framework, a 24-fold leave-one-out cross validation was conducted for all subjects. Both methods with each individual model achieved satisfactory performance, with low mean square error (MSE, 0.14 and 0.47) between the resultant evaluation score and the MAS. By contrast, the method using SVR to fuse biomarkers from both models outperformed other two methods with the lowest MSE at 0.059. The experimental results demonstrated the usability and feasibility of the proposed framework, and it provides an objective, quantitative and convenient solution to spasticity assessment, suitable for clinical, community, and home-based rehabilitation.

Optimal nutrition during pregnancy is vital for both maternal and child health. Our objective was to explore if prenatal diet is associated with children’s height and body fat. Nutrient intake was assessed through a food-frequency questionnaire from 808 pregnant women and summarized to a nutrition index, \"My Nutrition Index\"(MNI). The association with children’s height and body fat (bioimpedance) was assessed with linear regression models. Secondary analysis was performed with BMI, trunk fat and skinfolds. Overall, higher MNI score was associated with greater height (β=0.47; (95% CI: 0.00, 0.94), among both sexes. Among boys, higher MNI was associated with 0.15 higher BMI z-scores, 0.12 body fat z-scores, 0.11 trunk fat z-scores, and larger triceps, and triceps + subscapular skinfolds (β=0.05 and β=0.06; on the log2 scale) (p-value<0.05). Among girls, the opposite associations were found with 0.12 lower trunk fat z-scores, and smaller subscapular and suprailiac skinfolds (β= -0.07 and β= -0.10; on the log2 scale) (p-value<0.05). For skinfold measures this would represent a ±1.0 millimeters difference. Unexpectedly, a prenatal diet in line with recommended nutrient intake was associated with higher measures of body fat for boys and opposite to girls at a pre-pubertal stage of development. 

In sports and movement sciences isometric muscle function is usually measured by pushing against a stable resistance. However, subjectively one can hold or push isometrically. Several investigations suggest a distinction of those forms. The aim of this study was to investigate whether these two forms of isometric muscle action can be distinguished by objective parameters in an interpersonal setting. 20 subjects were grouped in 10 same sex pairs, in which one partner should perform the pushing isometric muscle action (PIMA) and the other partner executed the holding isometric muscle action (HIMA). The partners had contact at the distal forearms via an interface, which included a strain gauge and an acceleration sensor. The mechanical oscillations of the triceps brachii (MMGtri) muscle, its tendon (MTGtri) and the abdominal muscle (MMGobl) were recorded by a piezoelectric-sensor-based measurement system. Each partner performed three 15s (80% MVIC) and two fatiguing trials (90% MVIC) during PIMA and HIMA, respectively. Parameters to compare PIMA and HIMA were the mean frequency, the normalized mean amplitude, the amplitude variation, the power in the frequency range of 8 to 15 Hz, a special power-frequency ratio and the number of task failures during HIMA or PIMA (partner who quit the task). A “HIMA failure” occurred in 85% of trials ( p < 0.001). No significant differences between PIMA and HIMA were found for the mean frequency and normalized amplitude. The MMGobl showed significantly higher values of amplitude variation (15s: p = 0.013; fatiguing: p = 0.007) and of power-frequency-ratio (15s: p = 0.040; fatiguing: p = 0.002) during HIMA and a higher power in the range of 8 to 15 Hz during PIMA (15s: p = 0.001; fatiguing: p = 0.011). MMGtri and MTGtri showed no significant differences. Based on the findings it is suggested that a holding and a pushing isometric muscle action can be distinguished objectively, whereby a more complex neural control is assumed for HIMA.

Due to poling action and upper body engagement, Nordic walking (NW) has additional health benefits with respect to conventional walking. The aim of this study was to evaluate the differences in muscle activation and metabolic responses between NW, performed with the technique suggested by NW instructors, and with some modifications in the way to move upper limb and poles. Ten NW instructors volunteered to walk on a treadmill at 5.5 km•h-1 in five conditions: walking (W), Nordic walking (NW), NW with a weak poling action (NWweak), with straight-upper limbs moving the shoulders (NWshoulder) and with elbow flexion-extension pattern and shoulder freezed (NWelbow). Poling forces, body segments and poles movement, upper and lower body muscle activation, as well as metabolic parameters were measured.All modified NW techniques elicited lower muscular activation and metabolic responses with respect to the suggested NW technique (P < 0.05). All NW techniques elicited higher muscular activation and metabolic responses than W. All parameters observed with the NWweak were lower than NW. A decreased activation of shoulder extensor muscles and increased activation of anterior deltoid muscle were the main features of NWshoulder. Lower triceps brachii muscle activation and reduced propulsive poling action with respect to NW were seen for NWelbow, resulting also in shorter steps.Nordic walking instructors, sport technicians and practitioners should be aware that any deviation from the technique usually suggested might lead to lower benefits. However it is worth to note that any walking technique with poles elicits higher metabolic responses and muscular activation than walking.

This study attempts to analyze the relationship between free-throw efficiency and the time of arm muscle activation in players from 3 basketball teams with different levels of experience was investigated. During the experiment each player made 20 free throws during which the activation time of his right and left biceps and triceps brachii muscles were measured with the use of surface electromyography and high-speed cameras. Significant differences in muscle activation time (t) during a free throw were found between the groups of basketball players (p = 0.038) (novices: t = 0.664 ± 0.225 s, intermediate-level players: t = 1.15 ± 0.146 s, experts: t = 1.01 ± 0.388 s). In the right triceps brachii muscle in expert basketball players the coefficient of variation (CV) amounted to 44.60% at 81% efficiency, and in novices to 27.12% at 53% efficiency. The time of arm muscle activation during a free throw and its fluctuations vary along with the training experience of basketball players. In all studied groups of players, the variability of muscle activation time in accurate free throws is greater than in inaccurate free throws. Free-throw speed is irrelevant for free-throw efficiency.