Reply to the letter to the editor of L. Russo et al. concerning “Relationship between sagittal spinal curves geometry and isokinetic trunk muscle strength in adults” by W. Elsayed, A. Farrag, Q. Muaidi, N. Almulhim (2018) Eur Spine J 27:2014–2022

[摘要] A Letter to the Editor has been submitted concerning our recently published article [1]. The authors stated that the data collection instrument, Formetric 4D System (DIERS International GmbH, Germany), for spinal postural assessment is invalid and lacks accuracy. In this reply, we will refute the proposed assumptions.