Pre-clinical disability refers to a transitional state on the disablement pathway between impairment and disability that is characterised by early changes to task performance, but precedes self perception of difficulty with task performance[ 11].
Our underlying conceptual framework for defining health was the disablement process, beginning with disease/pathology, through functional limitation to disability[ 25].
We chose the disablement process over other disability models, among other reasons, because it considers the stages in disablement as an explicit sequence of linked events, one leading to the next.
Poor lower-body function plays a crucial role in the disablement process and has been associated with increased disability days, physician contacts, fear of falling, falls, hip fracture, depression, nursing home placement, and mortality [ 2, 3].
In studying the development of disability in RA, we proposed a theoretical framework [ 10], which we based on the disablement process that occurs with aging [ 8].
29 Depressive symptoms therefore contribute to the "disablement process speeding up disease to disability".
The instrument parallels the disablement framework described by Nagi on disability in community-dwelling older adults and correlates well with the physical functioning subscale of the Medical Outcomes Study 36-item Short Form (SF) Heandh Survey and the London Handicap Scale [ 27].
With the exception of the papers on the disablement model (Goal 6), we found that authors neither discuss nor try to envision how they would position their goal relative to other goals.
The reason for this finding is unknown however, it may relate to the complex nature of the disablement process [ 49] and the interaction with activity and behavioural factors associated with LBP [ 50].
The LLDFI, conceptually founded on the Disablement Process and Nagi models, is one of the few disability instruments that provides a comprehensive assessment of all aspects of progressive disablement and disability.
