AIMS: To explore ICU nurses' experiences of back and waist fatigue and establish a basis for developing effective intervention strategies to reduce low back muscle fatigue in the future. DESIGN: Qualitative study using focus group. METHODS: Eighteen ICU nurses participated in focus group interviews. Data were analysed using Nvivo11.0 software with content analysis. RESULTS: ICU nurses frequently suffer from lower back pain due to the severity of patient conditions and the use of numerous tubes and catheters, which often lead tounsafe postures. The absence of proper lifting systems exacerbates high-risk postures, contributing to acute lower back muscle injuries. Additionally, inadequate promotion of correct posture and prevention strategies, along with insufficent training on occupational hazards, futher exacerbates the issue. CONCLUSIONS: Human fator, machinery, environments, as well as their interactions significantly affect ICU nurses' experience of low back and waist muscle fatigue. REPORTING METHOD: Reported according to the SRQR (Standards for Reporting Qualitative Research) guideline. IMPACT: Offersnew insights into applying the human-machine-environment theory toto clinical nursing practice research. Highlightsthat the unconscious or passive adoption of poor postures by ICU nurses as a major factor contributing to muscles fatigue. Emphasizes the need for comprehensive intervention programsto prevent work-related low back muscle fatigue among ICU nurses. PATIENT OR PUBLIC CONTRIBUTION: Based on our findings, we have discussed the result with hospital management highlighting the urgent need for mesures to protect ICU nurses back and waist muscles. We believe this proactive approach is essentialfor ensuring the long-term well-being of healthcare professionals and maintaining the high standards of patient care.