“…This could be the case when type I MUs or mechanically specialized subpopulations of MUs [156] are spatially clustered, such as in muscle compartments that have been identified in animal experiments [151]. In several arm and shoulder muscles, among them the trapezius muscle, indications for compartmentalization have been found [15,50,59,60,92,104]. In addition, prolonged pressure at lower levels (8 h, 30 mmHg) can cause muscle fiber damage at normal blood pressure [46].…”