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Neuromuscular Physiology
Published in Michael H. Stone, Timothy J. Suchomel, W. Guy Hornsby, John P. Wagle, Aaron J. Cunanan, Strength and Conditioning in Sports, 2023
Michael H. Stone, Timothy J. Suchomel, W. Guy Hornsby, John P. Wagle, Aaron J. Cunanan
Skeletal muscle is made up of approximately 75% water, 20% protein, and 5% non-protein substances such as minerals, carbohydrates, and fats. There are approximately 650 muscles in humans, consisting of different sizes and shapes. Skeletal muscles are typically attached to bones at two or more places and create a lever system by crossing skeletal joints. The lever ends move closer together as a result of muscle contraction, thus creating movement and locomotion. Chapter 1 deals with the various macro and micro components of skeletal muscle, its innervation, and function.
Thermography by Specialty
Published in James Stewart Campbell, M. Nathaniel Mead, Human Medical Thermography, 2023
James Stewart Campbell, M. Nathaniel Mead
Although technically a myopathy, myositis is a condition causing inflammation in muscles. Infection, trauma (acute or chronic), autoimmune conditions, and drug effects may cause myositis (Table 11.1). Weakness, local swelling, and pain are the most common symptoms, generally occurring in central muscles in younger individuals, and in peripheral muscles in older subjects. The onset of myositis may herald an occult malignancy. Myositis involves local invasion of mast cells releasing histamine and macrophages generating NO.
Inflammatory Myopathy
Published in Maher Kurdi, Neuromuscular Pathology Made Easy, 2021
In muscle biopsy, myositis is histologically characterized by the presence of myonecrosis, regeneration, and inflammation (Figure 20.1a). It is sometimes difficult to reach a specific diagnosis by only hematoxylin and eosin (H&E) stain and the pathologist may sign the case as either inflammatory myositis (non-specific) or necrotizing myopathy. Sub-diagnosis comments, where pathologists can explain the histopathological findings within the clinical context, are important for the clinician.
Growth differentiation factor-15 as an emerging biomarker for identifying myositis
Published in Expert Review of Clinical Immunology, 2022
A heterogeneous group of rare muscle diseases are due to autoimmune processes that target the skeletal muscle tissue, and are termed myositis. Division of myositis patients in subgroups relevant to disease management are continuously refined and scrutinized [1–7], and myositis may associate with risk of malignancy [8]. Different patient subgroups present with distinct clinical and myopathological characteristics, and differing disease prognosis and therapeutic response. Diagnostic criteria include disease phenotyping, clinical testing, and assaying muscle damage patterns with electromyography, magnetic resonance imaging and histopathologic evaluation in a muscle biopsy. To aid subtyping of patients, an expanding variety of myositis-specific and myositis-associated autoantibodies are being described. The major subgroups recognized today are immune-mediated necrotizing myopathy (IMNM), dermatomyositis (DM), sporadic inclusion body myositis (IBM), polymyositis (PM), and myositis as part of the anti-synthetase syndrome (ASS).
A pilot study of children and parents experiences of the use of a new assistive device, the electro suit Mollii
Published in Assistive Technology, 2021
Birgitta Nordstrom, Maria Prellwitz
Cerebral palsy (CP) describes a group of permanent disorders in the development of movement and posture, causing limitations in activity due to a non-progressive neurological disorder that occurred in the developing brain. The motor disturbance is often accompanied by other disorders such as epilepsy and secondary musculoskeletal problems (Rosenbaum et al., 2007). In Sweden, one out of 400 children are diagnosed with CP, making it the most common cause of impaired motor function in children (Hägglund, 2013). Common impairments associated with CP are muscle weakness, incoordination, and spasticity, causing difficulties with everyday activities that can lead to activity limitations and restrictions in participation (Moreau et al., 2016). Restriction due to spasticity may, for example, create walking difficulties for the child (Beckung, Brogren, & Rösblad, 2002). These difficulties can negatively affect the child’s health and affect their ability to keep up with peers (Moreau et al., 2016). Spasticity generally involves sudden involuntary movements or convulsive muscle contractions. At present, there is no cure for spasticity, but there are different ways to try to manage it (Jacobs, 2001).
The effect of sitting position changes from pedaling rehabilitation on muscle activity
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2021
Lu Zongxing, Wei Xiangwen, You Shengxian
From Figure 9, the maximum activities of BFl, RF, SM, VI, VL, and VM are 78%, 75.6%, 49.8%, 75.2%, 92.5%, and 77%, respectively. The activity of these muscles are less than 100%, which shows that in the process of simulation, the limit of the muscles is not exceeded, and movement in horizontal position [−500 mm, −180 mm] and vertical height [500 mm, 700 mm] will not cause muscle damage. However, considering that the strength of the muscles varies and the strength of the patient’s muscles is reduced, preventing activity from being too high will cause secondary damage to low-intensity muscles. A comprehensive analysis of the activities of the abovementioned six main muscles, comparing the maximum activity of each muscle at different positions, can help obtain the comprehensive activity of these six muscles (Figure 10).