Innervation zones in the biceps brachii measured with a surface grid electrode

A back analysis system has been used to assess the occurrence of low back pain by evaluating the fatigue characteristics of back muscle during a sustained, constant-force trunk extension. A study was made to compare the median frequency values simultaneously obtained from six back muscles of patients (in remission, but having a history of chronic back pain) and normal control subjects. The median frequency was obtained while the subjects extended their trunks isometrically. Statistically significant (p >