The quantification of task-difficulty of upper limb motor function skill based on Rasch analysis

Area of Science:

• Rehabilitation Medicine
• Occupational Therapy
• Neuroscience

Background:

• The functional difficulty of paretic upper limb skills in daily life remains under-investigated.
• Stroke survivors often experience challenges with upper limb function, impacting independence.

Purpose of the Study:

• To evaluate the internal validity and item difficulty of the Functional Skills Measure After Paralysis (FSMAP).
• To establish a reliable tool for assessing daily living functional skills in stroke patients.

Main Methods:

• Rasch analysis was employed to examine the internal validity and difficulty levels of 65 items across 15 categories within the FSMAP.
• 105 first-stroke patients participated in the assessment.

Main Results:

• Eight items were identified as underfit (infit or outfit ≥1.5).
• "Shirt donning/doffing" was the easiest item (difficulty logit -35.8), while "Coin manipulation" was the most difficult (difficulty logit 41.5).
• Significant difficulty variations were noted, with "Trouser donning/doffing" and "Paper manipulation" showing high infit/outfit logits.

Conclusions:

• The FSMAP provides therapists with insights into patient performance and item difficulty.
• Understanding item difficulty facilitates the identification of appropriate functional skills for targeted rehabilitation post-stroke.