Bilateral thumb's active range of motion and strength in de Quervain's disease: comparison with a normal sample.

The aims of the present study were to characterize the thumb active range of motion (AROM) and strength impairments resulting from unilateral de Quervain's disease; to verify the adequacy of standard clinical assessment tools to quantify impairments resulting from this pathology; and to validate the utilization of the asymptomatic thumb as a reference to quantify the symptomatic thumb's deficits by comparing the performances of asymptomatic to control thumbs. The thumb's AROM and strength were evaluated bilaterally in 31 participants with unilateral de Quervain's disease and 18 control participants using clinical assessments involving the flexors and adductors of the thumb and experimental assessment devices measuring strength and mobility in several directions of the thumb's movements. A comparison was made between the results obtained from the symptomatic, asymptomatic, and control thumbs. The AROM performance of symptomatic thumbs was found to be reduced when compared to the asymptomatic and control thumbs for maximal thumb flexion (p=0.008 and 0.003, respectively) and total circumduction displacement (p<0.001). The strength performance of the symptomatic thumb was also found to be reduced when compared to the asymptomatic and control thumbs for palmar pinch strength (p<0.001 and 0.002, respectively) and for maximal voluntary effort in all directions (p<0.001). Differences in performance were also found between the asymptomatic and control thumbs, reaching the significance level for some movement parameters of the thumb circumduction evaluations and when palmar pinch strength results are normalized (p<0.001 and 0.009, respectively). This study revealed bilateral impairments of thumb AROM and strength for participants with de Quervain's disease, the impairments being more pronounced on the symptomatic side. This finding may question the validity of using the asymptomatic thumb as a standard measure to identify the symptomatic thumb's impairments associated with de Quervain's disease. The study also demonstrated the validity of using clinical evaluations when assessing impairments associated with this disease.