For normal shoulder joint movements, sternoclavicular articulation, the acromioclavicular joint, the glenohumeral joints, and the scapulothoracic joints should be coordinated. For remedial program after arthroscopic surgery for rotator damage, muscle exercise for the rotator should be regarded as an important factor, and clinical approaches should be adopted to promote muscle control and balanc...

[Purpose] This study was performed to determine which set of below-knee working conditions minimizes upper extremity muscle activity and which of upward- or downward-direction workstations poses the greater risk of upper extremity disorder. [Subjects] The study population consisted of 15 young male workers. [Methods] EMG activities of the right anterior deltoid, biceps brachii, and lower trapez...

[Purpose] This study examined the differences in the activities of three parts of the trapezius muscle-the upper trapezius (UT), middle trapezius (MT), and lower trapezius (LT)-among three different rotation conditions of the shoulders, while subjects performed prone horizontal abduction (PHA) at 30°, 60°, 90°, and 120° of abduction. [Subjects and Methods] The subjects of this experimental stud...

Work related musculoskeletal disorders (WMSDs) in the neck/shoulder area and the upper extremities are common among computer users, despite the relatively low muscle load levels involved. Muscle pain (myalgia), primarily experienced in the neck/shoulder area, is a frequent type of WMSD. The Cinderella hypothesis postulates that groups of muscle fibres (motor units, MUs) are continuously active ...

OBJECTIVES Myofascial trigger points (MTrPs) are considered the principal clinical feature of myofascial pain syndrome (MPS). An MTrP consists of spot tenderness within a taut band of muscle fibers and its stimulation can produce both local and referred pain. The clinical diagnosis of MPS depends on correct history taking and a physical examination aimed at identifying the presence of MTrP. The...

[Purpose] The purpose of this study was to identify changes in the activity and fatigue of the splenius capitis and upper trapezius muscles, which are agonists to the muscles supporting the head, under the three postures most frequently adopted while using a smartphone. [Subjects and Methods] The subjects were 15 college students in their 20s. They formed a single group and had to adopt three d...