Psoas MusclesPsoas AbscessMusclesMuscle ContractionMuscle Fibers, SkeletalRabbitsSarcomeresIsometric ContractionMuscle, SkeletalMyosinsMyofibrilsMuscle ProteinsMagnesium CompoundsMuscle RelaxationTroponin CReflex, StretchPhotolysisMuscle, SmoothAdenosine TriphosphateParaspinal MusclesMuscle, Smooth, VascularPhosphatesBiophysical PhenomenaCalciumAdenosine DiphosphateActomyosinMuscle Fibers, Fast-TwitchMuscle DevelopmentBiomechanical PhenomenaMuscle Fibers, Slow-TwitchBiophysicsX-Ray DiffractionTroponinKineticsRetroperitoneal SpaceActinsGlycerolElasticityMyosin SubfragmentsMuscle SpindlesActin CytoskeletonRhodaminesMuscle FatigueModels, BiologicalAdenosine TriphosphatasesMuscle DenervationOsmolar ConcentrationDiscitisThighLumbosacral PlexusStress, MechanicalMyocytes, Smooth MuscleTemperatureMuscle Rigidity