
Keywords: ایالات مؤتلفهٔ آمریکا; BMI; body mass index; CSA; cross sectional area; Dmax; maximal muscle belly displacement; ES; erector spinae; LBP; low back pain; LDS; laser displacement sensor; MMG; mechanomyography; MT; multifidus; TNS; transcutaneous neuromuscular stimulation; SEM; st