How sIBM affects individuals is variable, as is the age of onset (which generally varies from the forties upwards). Because sIBM affects different people in different ways and at different rates, there is no "textbook case". Eventually, sIBM results in general, progressive muscle weakness. The quadriceps and forearm muscles are usually affected early on. Common early symptoms include frequent tripping and falling, weakness going upstairs and trouble manipulating the fingers (including difficulty with tasks such as turning doorknobs or gripping keys). Foot drop in one or both feet has been a symptom of<unk>  and advanced stages of polymyositis (PM). During the course of the illness, the patient's mobility is progressively restricted as it becomes difficult to bend down, reach for things, and walk quickly. Many patients say they have balance problems and fall easily, as the muscles cannot compensate for an off-balanced posture. Because sIBM makes the leg muscles weak and unstable, patients are very vulnerable to serious injury from tripping or falling down. Although pain has not been traditionally part of the "textbook" description, many patients report severe muscle pain, especially in the thighs. When present, difficulty swallowing (dysphagia) is a progressive condition in those with<unk>  and often leads to death from aspiration pneumonia. Dysphagia is present in 40 to 85% of<unk>  cases.<unk>  can also result in diminished capacity for aerobic exercise. This decline is most likely a consequence of the sedentary lifestyle leading to disuse muscle atrophy that is often associated with the symptoms of<unk>  (i.e. progressive muscle weakness, decreased mobility, and increased level of fatigue). Therefore, one focus of treatment should be the improvement of aerobic capacity. Patients with sIBM usually eventually need to resort to a cane or a walker and in most cases, a wheelchair eventually becomes a necessity. "The progressive course of s-IBM leads slowly to severe disability. Finger functions can become very impaired, such as manipulating pens, keys, buttons, and zippers, pulling handles, and firmly grasping handshakes. Arising from a chair becomes difficult. Walking becomes more precarious. Sudden falls, sometimes resulting in major injury to the skull or other bones, can occur, even from walking on minimally irregular ground or from other minor imbalances outside or in the home, due to weakness of quadriceps and gluteus muscles depriving the patient of automatic posture maintenance. A foot-drop can increase the likelihood of tripping. Dysphagia can occur, usually caused by upper esophageal constriction that often can be symptomatically improved, for several months to years, by bougie dilation per a GI or ENT physician. Respiratory muscle weakness can sometimes eventuate."
Inclusion body myositis
Dermatomyositis
Nemaline myopathy
Polymyositis
Dermatopolymyositis
Centronuclear myopathy
Hereditary inclusion body myopathy
Brody myopathy