Towards a short questionnaire for stepwise assessment of upper limb function,pain and stiffness in Duchenne muscular dystrophy

Purpose: Duchenne muscular dystrophy can lead to upper extremity limitations, pain and stiffness. In a previous study, these domains have been investigated using extensive questionnaires, which are too time-consuming for clinical practice. This study aimed at gaining insight into the underlying dimensions of these questionnaires, and to construct a short questionnaire that can be used for clinical assessment.

Methods: Exploratory factor analysis was performed on the responses of 213 participants to a web-based survey to find the underlying dimensions in the Capabilities of Upper Extremity questionnaire, the ABILHAND questionnaire, and questionnaires regarding pain and stiffness. Based on these underlying dimensions, a stepwise approach was formulated. In addition, construct validity of the factors was investigated.

Results: In total, 14 factors were identified. All had high internal consistency (Cronbach's alpha >0.89) and explained 80–88% of the variance of the original questionnaires. Construct validity was supported, because participants in the early ambulatory stage performed significantly better (pConclusion: The factors identified from the set of questionnaires provide a valid representation of upper extremity function, pain and stiffness in Duchenne muscular dystrophy. Based on the factor commonalities, the Upper Limb Short Questionnaire was formulated.

• Implications for Rehabilitation

• New insights into the underlying dimensions of upper extremity function, pain and stiffness in Duchenne muscular dystrophy are gained.

• Fourteen factors, with good internal consistency and construct validity, are identified regarding upper extremity function, pain and stiffness in Duchenne muscular dystrophy. Based on these factors, the Upper Limb Short Questionnaire is presented.

• The Upper Limb Short Questionnaire can be used as an identifier of arm-hand limitations and the start of more thorough clinical investigation.