Short Tilte:Elbow extension using anterior deltoids and upper pectorals in spinal cord-injured subjects
Journal:Archives of Physical Medicine & Rehabilitation
Year, Volume, Issue, Page(s):95, 76, 5, 426-432
Reports a study that evaluated the electromyographic (EMG) activity in a voluntary kinetic closed chain elbow extension of individuals with C6 motor level spinal cord injuries. Subjects were from a regional spinal cord injury center and had a C6 motor level on the right side. A total of six subjects came for testing. All subjects performed a series of isometric elbow extension contractions of 25 percent, 50 percent, and 75 percent of maximum voluntary contraction (MVC) as measured by a force transducer. Researchers measured surface EMG of the right elbow extensor, anterior deltoid, and upper pectoral muscles using the root mean square (rms) of the amplitude of the motor unit activity as the parameter of muscle activity. Statistical analysis indicated that for each muscle tested, there was significantly greater rms activity for each percentage of MVC except between 50 percent and 75 percent MVC of the elbow extensor muscle. The elbow extensor muscle had minimal EMG activity as compared to the amplitude of the rms activity of the anterior deltoid and upper pectoral muscles for each percentage of MVC. The study indicates that the anterior deltoid and upper pectoral muscles exert an isometric elbow extension force for individuals with C6 quadriplegia.