Differential diagnosis:
(1) muscle strain
(2) muscle tear and/or hematoma
(3) localized rhabdomyolysis
Historical features:
(1) level of exercise relative to conditioning of patient. An unconditioned person starting an exercise program is likely to have strain, as is a conditioned person after excessively strenuous exercise.
(2) Blunt trauma, as in football players or collision with equipment.
(3) Rhabdomyolysis may be associated with viral infection, recent alcohol excess, or medications.
Physical finding may show swelling in the muscle with pain on contraction of the muscles. In muscle strain tenderness may be present over the insertion into the os pubis.
Ultrasound may show muscle swelling and/or echo-dense areas in rhabdomyolysis.
In rhabdomyolysis, the serum creatine kinase (CK) is markedly elevated.
