Intramuscular Pressure and Electromyography in the Supraspinatus Muscle at Shoulder Abduction

Gender adjustment or stratification in discerning upper extremity musculoskeletal disorder risk?

“…To assess the effects of physical exposures imposed on the upper extremities in work activities, we focused first on determining the optimal cut points for each of the exposure variables based on the previous, although limited, epidemiological literature (29-36), biomechanical and physiological studies (37)(38)(39)(40)(41), and the distributions of the data in our study population.…”

Work postures and neck–shoulder pain among orchestra musicians

“…For each instrument, arm elevation while playing was assessed by the authors using photographs of experienced instrumentalists playing each of the instruments and were classified into: (a) Elevated arm position (!408 elevated arm position while playing), or (b) Neutral arm position (<408 elevated arm position while playing). This cut-off for elevated arms (>408) was chosen in line with an earlier study by Jarvholm et al [1989] who found that even at a moderate arm elevation of >308, blood flow in the supraspinatus muscle was impaired.…”

Effect of speed and precision demands on human shoulder muscle electromyography during a repetitive task

“…It has been shown that arm posture is a major determinant for the mechanical load on the tissues in the shoulder region and muscle activity relates to arm elevation as measured by electromyography (EMG) or intramuscular pressure (Sigholm et al 1984;JaÈ rvholm et al 1989). The plane of elevation, for example¯exion versus abduction, and the magnitude and direction of the external force have been found to modulate the response of the individual shoulder muscles (Mathiassen and Winkel 1990;Jensen et al1995;Laursen et al 1997).…”