Musculoskeletal disorders among nursing assistants in Spain; a comparative study between old people’s homes and hospitals

•Greater frequency of back-related injuries at old people’s homes than in hospitals.•Greater frequency of shoulder-related injuries in hospitals.•Hour: More injuries between 8 to 10 at old people’s homes, and 11 to 14 in hospitals.•Duration of sick leave in musculoskeletal injuries is 8.7 days higher at hospitals. An analysis of musculoskeletal injuries among nursing assistants and the duration of sick leave due to musculoskeletal-related injuries is presented. 33,200 injuries are analyzed in Spain, over the period 2013–2017. Our results showed differences for injuries, their causes and injured body parts, confirming a greater frequency of back-related injuries at old people’s homes, and of shoulder-related injuries at hospitals. As regards organization at work, the highest number of injuries at old people’s homes and hospitals were registered between 8:00 and 10:00 and, between 11:00 and 14:00 h, respectively. The average duration of sick leave at hospitals (35.63 days) was higher than at old people’s homes (26.89). Differences that were influenced by the older average age of hospital workers. The lengthier duration of sick leave was associated with centers within the public sector. These results recommend active breaks and physical exercise for older workers, reviewing sick leave at public centers and the incorporation of ergonomic training.