Ultrasound evaluation in combination with finger extension force measurements of the forearm musculus extensor digitorum communis in healthy subjects

<p>Abstract</p> <p>Background</p> <p>The aim of this study was to evaluate the usefulness of an ultrasound-based method of examining extensor muscle architecture, especially the parameters important for force development. This paper presents the combination of two non-invasive methods for studying the extensor muscle architecture using ultrasound simultaneously with finger extension force measurements.</p> <p>Methods</p> <p>M. extensor digitorum communis (EDC) was examined in 40 healthy subjects, 20 women and 20 men, aged 35–73 years. Ultrasound measurements were made in a relaxed position of the hand as well as in full contraction. Muscle cross-sectional area (CSA), pennation angle and contraction patterns were measured with ultrasound, and muscle volume and fascicle length were also estimated. Finger extension force was measured using a newly developed finger force measurement device.</p> <p>Results</p> <p>The following muscle parameters were determined: CSA, circumference, thickness, pennation angles and changes in shape of the muscle CSA. The mean EDC volume in men was 28.3 cm³and in women 16.6 cm³. The mean CSA was 2.54 cm²for men and 1.84 cm²for women. The mean pennation angle for men was 6.5° and for women 5.5°. The mean muscle thickness for men was 1.2 cm and for women 0.76 cm. The mean fascicle length for men was 7.3 cm and for women 5.0 cm. Significant differences were found between men and women regarding EDC volume (p < 0.001), CSA (p < 0.001), pennation angle (p < 0.05), muscle thickness (p < 0.001), fascicle length (p < 0.001) and finger force (p < 0.001). Changes in the shape of muscle architecture during contraction were more pronounced in men than women (p < 0.01). The mean finger extension force for men was 96.7 N and for women 39.6 N. Muscle parameters related to the extension force differed between men and women. For men the muscle volume and muscle CSA were related to extension force, while for women muscle thickness was related to the extension force.</p> <p>Conclusion</p> <p>Ultrasound is a useful tool for studying muscle architectures in EDC. Muscle parameters of importance for force development were identified. Knowledge concerning the correlation between muscle dynamics and force is of importance for the development of new hand training programmes and rehabilitation after surgery.</p

Computational Intelligence in Electromyography Analysis

Electromyography (EMG) is a technique for evaluating and recording the electrical activity produced by skeletal muscles. EMG may be used clinically for the diagnosis of neuromuscular problems and for assessing biomechanical and motor control deficits and other functional disorders. Furthermore, it can be used as a control signal for interfacing with orthotic and/or prosthetic devices or other rehabilitation assists. This book presents an updated overview of signal processing applications and recent developments in EMG from a number of diverse aspects and various applications in clinical and experimental research. It will provide readers with a detailed introduction to EMG signal processing techniques and applications, while presenting several new results and explanation of existing algorithms. This book is organized into 18 chapters, covering the current theoretical and practical approaches of EMG research

A comparative study of tendinous interconnection in the forearm and hand of human cadavers and live subjects

Certain complex hand functions such as playing musical instruments, buttoning and writing require the action of the long flexor tendons. Repeated movements of these tendons cause inflammatory changes resulting in an increase in the Tendon Cross Sectional Area (TCSA), and, subsequently, tendinous interconnections (occurs in approximately 20% of the general population, commonly between the flexor pollicis longus [FPL] and index finger flexor digitorum profundus [FDP] - Linburg-Comstock syndrome). Coupled with an anatomically congested space at the wrist, such interconnections may compress the median nerve resulting in carpal tunnel syndrome. This study evaluated the prevalence of tendinous interconnection amongst 200 medical students at Cardiff University by a series of structured hand movements (n=12) in controlled setting. The findings were corroborated using Ultrasound Scan (USS) (n=4) and Magnetic Resonance Imaging (MRI) (n=1). The muscle mass, fibre length, density, angle of pennation and tendon length were ascertained by studying hands and forearms (n=30) of embalmed human cadavers. The data was used to determine the Physiological Cross Sectional Area (PCSA) and calculate the relation between PCSA and TCSA. Simple linear regression established the direct relation of PCSA to TCSA, muscle mass and tendon length. A direct relation between the TCSA of FPL and index finger FDP was identified. The cross sectional area of the median nerve increases as it traverses the carpal tunnel. The PCSA had no bearing on density and angle of pennation. USS was found to be more dynamic and sensitive than MRI in identifying tendinous and tenosynovial interconnections, as the tenosynovial interconnections <1 mm thick could be recognised. The study also (i) identified a lower percentage of tendinous interconnection (compared to the literature) in a randomly selected group of individuals, (ii) detected the limitation of photograpic measurements to study angles of finger movements and (iii) highlighted the disadvantage of calculating PCSA in cadavers

The Effects of Resistance Training on Architecture and Volume of the Upper Extremity Muscles: A Systematic Review of Randomised Controlled Trials and Meta-Analyses

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

Supporting and Locomotor Appаratus

Посібник рекомендований для студентів вищих медичних навчальних за-кладів IV рівня акредитації, які вивчають анатомію людини англійською мовою.This manual is intended for the students of medical higher educational institu-tions of IV accreditation level, who study Human Anatomy in the English language